MODELS FOR ESTIMATING BIOMASS AND CARBON IN BIOMASS AND
SOILS IN Pinus adia a (D. Don), Eucalyp us globulus (Labill) AND
Eucalyp us ni ens (Deane & Maiden) Maiden PLANTATIONS ESTABLISHED
IN FORMER AGRICULTURAL LANDS IN NORTHWESTERN SPAIN
Depa amen o de P oducción Vege al
Escuela Poli écnica Supe io
Césa Pé ez-C uzado
Doc o al Thesis
June 2011
UNIVERSIDAD DE SANTIAGO DE COMPOSTELA
ESCUELA POLITÉCNICA SUPERIOR
DEPARTAMENTO DE PRODUCCIÓN VEGETAL
MODELS FOR ESTIMATING BIOMASS AND CARBON IN
BIOMASS AND SOILS IN Pinus adia a (D. Don), Eucalyp us
globulus (Labill) AND Eucalyp us ni ens (Deane & Maiden)
Maiden PLANTATIONS ESTABLISHED IN FORMER
AGRICULTURAL LANDS IN NORTHWESTERN SPAIN
TESIS DOCTORAL
A
UTOR:
CÉSAR PÉREZ-CRUZADO
DIRECTORES:
DR. D. ROQUE RODRÍGUEZ SOALLEIRO
DR. D. AGUSTÍN MERINO GARCÍA
Lugo, Junio 2011
UNIVERSIDAD DE SANTIAGO DE COMPOSTELA
ESCUELA POLITÉCNICA SUPERIOR
DEPARTAMENTO DE PRODUCCIÓN VEGETAL
MODELS FOR ESTIMATING BIOMASS AND CARBON IN
BIOMASS AND SOILS IN Pinus adia a (D. Don), Eucalyp us
globulus (Labill) AND Eucalyp us ni ens (Deane & Maiden)
Maiden PLANTATIONS ESTABLISHED IN FORMER
AGRICULTURAL LANDS IN NORTHWESTERN SPAIN
CÉSAR PÉREZ-CRUZADO
INGENIERO DE MONTES
Memo ia pa a op a al g ado de Doc o ealizada bajo la di ección de los Doc o es del Depa amen o de
P oducción Vege al y Eda ología y Química Ag ícola de la Uni e sidad de San iago de Compos ela:
DR. D. ROQUE RODRÍGUEZ SOALLEIRO DR. D. AGUSTÍN MERINO GARCÍA
Vº Bº
El di ec o
Vº Bº
El di ec o
DR. D. ROQUE RODRÍGUEZ SOALLEIRO
DR.
D.
A
GUSTÍN MERINO G
A
RCÍ
A
El au o
D.
CÉSAR PÉREZ-CRUZADO
Lugo, Junio 2011

El D . D. Roque Rod íguez Soallei o, P o eso Ti ula del Depa amen o de P oducción Vege al
de la Uni e sidad de San iago de Compos ela y D . D. Agus ín Me ino Ga cía, P o eso Ti ula del
Depa amen o de Eda ología y Química Ag ícola de la Uni e sidad de San iago de Compos ela, in o man:
Que la memo ia i ulada “Models o es ima ing biomass and ca bon in biomass and soils in Pinus
adia a (D. Don), Eucalyp us globulus (Labill) and Eucalyp us ni ens (Deane & Maiden) Maiden
plan a ions es ablished in o me ag icul u al lands in no hwes e n Spain”, que pa a ob ene el g ado
de Doc o Ingenie o de Mon es p esen a D. Césa Pé ez C uzado, ha sido ealizado bajo nues a
di ección. Conside ando que el abajo es á inalizado, y es ma e ia de esis, au o izamos su p esen ación.
Y pa a que así cons e a los e ec os opo unos, i mamos la p esen e en Lugo a 22 de Junio de
2011.
LOS DIRECTORES
Fdo. DR. D. ROQUE RODRÍGUEZ SOALLEIRO Fdo. DR. D. AGUSTÍN MERINO GARCÍA
Los abajos lle ados a cabo pa a la ealización de es a Tesis Doc o al han sido inanciados
median e los siguien es p oyec os de In es igación:
 “FORSEE: Ges ión sos enible de los bosques: Una ed de zonas pilo o pa a la pues a en
ma cha ope a i a” P oyec o inanciado po Inicia i a Comuni a ia de la Unión Eu opea
(Re . 020-FORSEE) median e el Fondo Eu opeo de Desa ollo Regional (FEDER -
In e eg IIIB A lan ic A ea). www.ie c.ne
 “Cap u a de ca bono en e enos ag ícolas epoblados con plan aciones o es ales pa a
uso made e o y ene gé ico” P oyec o inanciado median e el P og ama Nacional de
Recu sos y Tecnologías Ag oalimen a ias (Re . SUM2006-00006-00-00) po el Minis e io
de Educación y Ciencia y el Ins i u o Nacional de In es igación Ag a ia y Alimen a ia
(INIA), den o de la acción mo ilizado a “Sumide os ag o o es ales de e ec o
in e nade o”.
 “Es udio de la es abilización del ca bono en suelos ag ícolas e o es ados” Coo dinado
den o del p oyec o “CRONOCARB”, inanciado median e el Plan Nacional de I+D+I
2008-2011 (Re . AGL2009-13400-C05-04) po el Minis e io de Ciencia e Inno ación y el
Fondo Eu opeo de Desa ollo Regional.
Pa a la ealización de la p esen e Tesis Doc o al, el au o ha con ado con una beca p edoc o al del
P og ama de Fo mación de P o eso ado Uni e si a io (FPU-MEC, AP2007-04367) del Minis e io de
Educación (BOE 183, 30/07/2008), bajo la supe isión del P o eso D . D. Roque Rod íguez Soallei o,
den o del G upo de In es igación Unidade de Xes ión Fo es al Sos ible (www.usc.es/ux s).
AGRADECIMIENTOS:
Quie o exp esa mi sen imien o de g a i ud a odas aquellas pe sonas que, de alguna u o a o ma,
han colabo ado en la elabo ación del abajo que aquí concluye. Debido a que son muchas las pe sonas
que me han ayudado du an e es os años, espe o since amen e no habe me ol idado de nadie.
Muy especialmen e a mis di ec o es, Roque Rod íguez Soallei o y Agus ín Me ino, po la
dedicación y el a o ecibido en odo momen o, así como po habe me con agiado ues a pasión po la
in es igación. Espe o no habe ago ado ues as ganas de segui di igiendo esis.
A Nie es y Pepi del Dep o. de Física Aplicada po la ines imable ayuda con los análisis é micos y
NMR, con ado po oso as odo pa ece más ácil. A los p o eso es y p o eso as del G upo de In es igación
Unidade de Xes ión Fo es al Sos ible Juan Gab iel Ál a ez, Guille mo Riesco, Albe o Rojo, Ulises Diéguez,
Fede ico Sánchez, Fina Lomba de o, Ana Da ía, Ca los López y Manuel Guai a. También a odos los
p o eso es y p o eso as del Depa amen o de P oducción Vexe al y Eda oloxía e Química Ag ícola de la
Escuela Poli écnica Supe io , a los que he ecu ido en nume osas ocasiones. A Almudena Pé ez po es a
siemp e ahí, solucionando sob e la ma cha nues os p oblemas, muchas g acias po odo.
A F i s Moh en, F ans Bonge s, S e an Schni ze , Ellen Wilde ink, U e Sass-Klaassen, Lou ens
Poo e , Ma ielos Peña, Joke Jansen, Jan den Ouden, F ank S e ck, La s Ma kes eijn, Jose Que o, Pa ick
Jansen, Gus a o Schwa z, Co neille Ewango, Meenakshi Kaul, Ma isol Toledo, Es on Munyanziza, Hans
Polman, Leo Goudzwaa d, Lucy Amissah, Geo ana Ca eño, Abeje Eshe e, Mo uma Tole a, Neel je an
Hul en y al es o del pe sonal del Fo es Ecology and Fo es Managemen G oup (Wageningen Uni e si y),
po la dedicación y el buen a o ecibido du an e mi es ancia en Holanda. Heel e g bedank oo alles!
A Fe nando Basu co y Robe o As o ga (ENCE), Ca los Tejedo (SNIACE), Gab iel To al (CIFA-
Lou izán), Miguel Balboa (No en o), Fe nando Solla-Gullón (ISEMPA), Gus a o Iglesias (GIT), Ana
Cabanei o e I ene Fe nández (CSIC) po las con ibuciones como expe os en ues as espec i as
ma e ias. A Edelmi o, Robe o, Pacín, A ias, Jose Luis, Manuel, Fe nado, Robe o Vila, Román, Manuel
Vázquez, Julio, José Manuel y el es o de p opie a ios de las pa celas. A Mon se a Gómez, y Ve ónica
Piñei o po su dedicación incondicional pa a cumpli los plazos con los análisis de mues as.
A Ho acio, Samuel, Pablo Mansilla y Juan Daniel po la ines imable ayuda en los abajos de
campo. A Luís, Benja, Elena, Nohe, Noelia, Albe o, Moisés y Hugo po habe os a e ido a hace el
p oyec o in de ca e a con noso os, sin oso os nada hubie a sido posible.
A odos los compañe os y amigos que han es ado a mi lado du an e oda la e apa de o mación,
muy especialmen e a: Luis Rod íguez DaCos a, Do i, Ja i Pe ei a,Tino, Edu González, Lau a, Ismael
Cas o, Ma a Ille a, And ea Fe ei o, Da id Cas añe, Sand a, Fe nando Solla, Bea Omil, C is ina Eimil,
Es eban, And ea He ia, Felipe C ecen e, Fe nando Pé ez, E a, Iban, I onne, Pablo Guindos, Emmanuel,
Ra a, Noelia, Vanesa, Susi, Na alia. Muchas g acias po an os buenos momen os.
Y, po supues o, a oda mi amilia, especialmen e a mis pad es: A u o, Me cedes, Begoña y
Al onso; a mi he mano Da id, a mis abuelos y abuelas: Vidalina, Ani a, Facundo, Jesusa y Rosa. A mi
abuelo Facundo†.
Po úl imo y muy especialmen e a Bea, po u paciencia, comp ensión y ayuda. Espe o i i lo
su icien e pa a de ol e e odo el iempo que e debo.
Muchas g acias a od@s.
INDEX AND ABSTRACT
0.2. Gene al abs ac
Clima e change is one o he mos se ious en i onmen al p oblems nowadays. This has been
b ough abou by he so-called g eenhouse e ec , caused by he huge elease o g eenhouse
gases, pa icula ly CO2, om he bu ning o ossil uels. Ene gy sec o s con ibu e mos o clima e
change, al hough land use and land use change also con ibu e g ea ly o he g eenhouse e ec .
Despi e he obse ed end owa ds de o es a ion in opical zones, land use changes in Eu ope
and No h Ame ica a e ending owa ds an inc ease in o es co e . This was accele a ed in
Eu ope by he implemen a ion o a policy encou aging a o es a ion o o me ag icul u al land
(EEC 2080/92), which led o a o es a ion o la ge a eas in no he n Spain be ween 1992 and
2006. This usually in ol ed plan ing as g owing species (Eucalyp us globulus Labill., Eucalyp us
ni ens (Deane & Maiden) Maiden and Pinus adia a (D. Don)) on o me pas u e land.
In e na ional ag eemen s on global C emissions allow he coun ies in ol ed o compensa e o
he elease o CO2 by p o iding C sinks. Howe e , he e is a la ge deg ee o unce ain y associa ed
wi h he me hods used o es ima e he amoun s o ca bon seques e ed, mainly when e alua ing
some compa men s o C sinks, e en in s eady s a e sys ems. The p ocess is mo e complica ed
when he land use unde s udy has no eached equilib ium, and addi ional s udies a e equi ed o
e alua e he e ec s on C s ocks.
Al hough es ima ion o he ca bon densi y in ee biomass is simple, i is much mo e di icul o
es ima e changes in ca bon densi y in soils. Mos ca bon dynamics s udies a e based on modelling
app oaches, and s udies based on empi ical da a a e equi ed o mo e consis en assessmen s,
and o p o ide in o ma ion o alida ing eco-physiological model p edic ions o o de eloping
empi ical models. Howe e , di ec measu ing is ime consuming and he esul s a e highly a iable
and do no always enable signi ican conclusions o be eached. Changes in soil ca bon a e
di icul o es ima e because hey occu ela i ely slowly, and some ex e nal a iables may also
a ec he inal es ima ion. Ch onosequence sampling combined wi h pai wise compa ison o plo s
may be a use ul echnique o ansla ing spa ial di e ences in o empo al di e ences, while also
co ec ing local endencies in he measu ed plo s, hus enabling es ima ion o he changes in he
a iable o in e es a landscape le el.
Ca bon in ees is usually es ima ed om biomass equa ions, which a e supposed o be mo e
use ul o biomass es ima ion han biomass expansion ac o s. Howe e , es ima ion o he d y
mass o he sample ees used in de eloping models may no be e y accu a e. Mo eo e , he
inc easing in e es in ha es ing c own ac ions and in ca ying ou ecological and nu i ional
s udies, leads o he need o mo e accu a e models. The s udy o c own a iables as explana o y
a iables in biomass equa ions may lead o he de elopmen o mo e accu a e models han hose
based exclusi ely on s em a iables.
P oduc yield is usually exp essed in e ms o ha es ed o p oduced wood olume, whe eas
bioene gy subs i u ion and ca bon s ocks a e exp essed in e ms o ene gy, o onnes o oil

CHAPTER 0
i
equi alen . This depends on he ans o ma ion p ocedu e, which inally leads o es ima ions om
s and olume o biomass by he applica ion o bioene gy p oduc ion ac o s. Rela ing each o hese
o ms o ene gy o ca bon di ec ly by he use o speci ic models may a oid conca ena ing e o s in
he es ima ion, and a he same ime enable compa ison o se e al managemen al e na i es o
he use o pa icula species o ene gy pu poses.
The i s s ep in es ima ing changes in soil o ganic ca bon (SOC) a e land use change is o
examine changes in o al SOC. Howe e , he s abili y o SOC compounds a ies g ea ly, and
adi ional echniques o desc ibing hese p ocesses a e ime consuming and expensi e. The
de elopmen o inexpensi e and apid al e na i e me hods o assessing changes in soil s abili y is
a key ac o o la ge scale o high empo al esolu ion s udies.
When e alua ing he whole o es sec o in e ms o clima e change mi iga ion, ca bon
accumula ion in wood p oduc s and he associa ed dynamics mus be conside ed, al hough i is
s ill no clea how his pool will be acc edi ed in in e na ional emissions ag eemen s. The mos
commonly used echniques a e hose based on mechanis ic models, e.g. he CO2Fix model, which
enables es ima ion o he mi iga o y e ec o se e al managemen al e na i es by conside ing all
compa men s in which ca bon can be s o ed. Howe e , ew s udies ha e been ca ied ou o
alida e he esul s ob ained wi h his model in sou he n Eu ope.
The aim o his doc o al hesis is o discuss modelling and es ima ion o C accumula ion in
o es sys ems, pa icula ly o es plan a ions. The s udy ocused on he h ee le els a which
ca bon can be es ima ed: ee, s and and landscape le el. The s udy in ol ed e alua ion o a
speci ic dynamic p ocess, i.e. he a o es a ion o o me pas u e land in no he n Spain. The main
esea ch ques ions add essed we e hus ela ed o his issue, wi h he aim o imp o ing he ools
and models used o quan i y ca bon s ocks and ca bon changes esul ing om land use change.
The s udy was ca ied in he empe a e o es o A lan ic sou he n Eu ope, one o he mos
p oduc i e imbe p oduc ion a eas in Eu ope.
The expe imen al design and me hods used o collec da a a e summa ised in he ollowing
poin s, co esponding o di e en chap e s o he hesis.
 A ne wo k o 120 pai ed plo s ( o me pas u e land-new plan a ions o di e en ages) was
es ablished o cons uc h ee well- eplica ed ch onosequences o he mos common ee
species in A lan ic empe a e a eas. The pai ed plo s ep esen ed he o iginal land use
(pas u e) and o es plan a ions es ablished on his land. In each o he ch onosequences,
ca bon densi y was es ima ed in abo eg ound biomass, li e and mine al soil o a dep h o
30 cm. Changes in ca bon in mine al soil and li e we e e alua ed by non pa ame ic
analysis, whe eas in li ing biomass, ca bon was calcula ed by eg ession analysis. The
e ec o o a ion age on C s ock o he a e age ends in he measu ed plo s was also
assessed.
 Fo y specimens o E. ni ens we e elled and comple ely esh weighed. The ee biomass
was di ided in o he ollowing componen s: wood, ba k, hick b anches, hin b anches,
wigs, lea es and dead b anches along he s em. In ensi e sampling was ca ied ou along
INDEX AND ABSTRACT
ii
he s em o e alua e he e ec o sampling in ensi y on d y mass es ima ion, by a io ype
es ima o s. Two di e en me hods we e compa ed: comple e esh weigh and d y mass
es ima ion using disks sampled along he s em (CW), and comple e s em cubica ion and
pa ial esh weigh o d y mass and a e age basic densi y es ima ion (PW). Mo eo e ,
he use ulness o c own a iables o desc ibing biomass c own biomass ac ions was
assessed. The u ili y o he models de eloped o es ima ing changes in biomass ac ions
p opo ion in abo eg ound biomass was assessed o di e en dimensional classes.
 Measu emen s made in o 15 addi ional plo s o E. globulus and 36 o E. ni ens
es ablished on o es land we e used o de elop s a ic g ow h models o hese species.
The h eshold densi y limi de i ed om sel - hinning and ha es ing we e conside ed o
model de elopmen , and enabled e alua ion o echnical and sil icul u al limi a ions o he
single s em o a ion. The models enabled e alua ion o he e ec o wo di e en ini ial
s ocking on bioene gy p oduc ion in se e al di e en ways, as well as ca bon accumula ion
o he wo eucalyp species s udied.
 Se e al soil samples we e collec ed in he E. globulus and P. adia a ch onosequence
plo s, o ep esen he a e age ends o hese species, and we e analysed by calo ime y
and he mal analysis, as no el echniques o elucida e how a o es a ion a ec s he na u e
o soil o ganic ma e (SOM) and soil mic obial me abolism. The esul s we e compa ed
wi h hose ob ained by solid s a e nuclea magne ic esonance, o en used o s udy SOM.
The applica ion o bo h echniques enabled es ima ion o he na u e o changes in SOC
ollowing land use change, and highligh ed he use ulness o calo ime y and he mal
analysis o dis inguishing soil o ganic compounds.
 The CO2Fix mechanis ic model was pa ame e ized wi h da a ob ained in he
abo emen ioned plo s, and wi h addi ional measu emen s ega ding o es indus y sec o
p oduc s luxes and pe o mance. De ailed measu emen s o all compa men s es ima ed
by he CO2Fix model in he 120 pai ed plo s (see abo e) enabled alida ion o he CO2Fix
model es ima ions o he condi ions unde s udy. De ailed wood indus ial sec o da a
we e ob ain o pa ame e izing he wood p oduc s module. This, oge he wi h p e iously
de eloped yield models and hypo heses ega ding he li espan o p oduc , was used o
e alua e he e ec s o wo di e en managemen al e na i es o he species conside ed,
in ela ion o clima e change mi iga ion.
Rega ding he changes in C a e land use change om pas u e o o es plan a ions (Chap e
II), he mean a es o C seques a ion (biomass and soil) es ima ed h oughou he o a ion anged
be ween 8.7 and 14.6 Mg C ha-1 y -1 (Eucalyp us ni ens > Eucalyp us globulus > Pinus adia a),
and he con ibu ion o he soil (li e plus mine al soil) anged om 8 o 18% (Eucalyp us ni ens >
Pinus adia a > Eucalyp us globulus). The humid empe a e clima e and he sandy loam ex u e o
he soils a ou ed la ge losses o SOC om he uppe mos mine al soils du ing he 10 yea s
ollowing a o es a ion. The losses we e de i ed om he la ge con en o SOM in he pas u e soils
in he egion. The highe losses o SOC om he pine soil (26% o ini ial SOC compa ed wi h loss
CHAPTER 0
iii
o 19.5% o ini ial he SOC om soil unde eucalyp s) we e a ibu ed o he lowe ans e o
o ganic C o he mine al soil, as a esul o he lowe li e decomposi ion a e and he lowe
belowg ound li e inpu om associa ed ege a ion. The la e ac o was a ibu ed o di e ences
in shading p o ided by he di e en species, which inally leads o di e en mic oclima ic condi ions
in he plan a ions. The clima e also a ou ed he apid de elopmen o ee biomass and
subsequen C seques a ion in biomass and soils.
In he s udy o he e ec s con olling he SOC accumula ion, soil ca bon losses om he uppe
mine al soil laye s in he plo s wi h he highes si e indexes we e lowe and eco e y o he ini ial
con en s ook place as e han in he o he plo s. The ini ial ca bon con en du ing he p e ious
land use was a signi ican ac o de e mining he changes in SOC ollowing land use change. The
ini ial ca bon losses and la e eco e y o ini ial ca bon con en s we e highes in plo s in which he
ini ial soil ca bon con en was highes . This e ec was signi ican o bo h species o Eucalyp us,
bu no o P. adia a, possibly because o he dea h o he baceous ege a ion in Pinus plan a ions
in he i s yea s a e land use change.
The esul s o non-pa ame ic analysis o a e age ends enabled e alua ion o he e ec o
di e en o a ion ages on C s ock and accumula ion a e o he h ee species s udied and he
compa men s conside ed. The C sink capaci y o o es plan a ions can be maximized by
leng hening he o a ion and adop ing sui able managemen s a egies o each species. This is
especially impo an in plan a ions in which he high in ensi y o ha es ing may p e en
accumula ion o SOC in he long e m.
In Chap e III, he in ensi e sampling conside ed o he s em componen enabled es ima ion o
he e ec o sampling in ensi y and ini ial sampling poin in he s em on he accu acy and bias in
es ima ion o s em wood d y mass by a io ype es ima o s and sys ema ic sampling. Fo bo h
me hodologies conside ed (CW and PW), he esidues we e plo ed agains sampling in ensi y,
and h esholds we e es ablished o keep he ela i e e o below 10%. The inc eases in mois u e
con en and basic densi y along he s em explained he se ious isk o d y mass o e es ima ion
when sys ema ic subsamples we e conside ed. O he me hods conside ed he e, he CW
app oach p oduced be e esul s o he la ges dimensional class han he PW me hod o a
simila sampling in ensi y. This is impo an because he PW me hod is usually used o la ge ees
in which comple e weighing is ime-consuming.
The esul s clea ly show he ends in ela i e e o s de i ed om measu emen o he bo om
disk o he bo om log, conside ed by de aul as he i s sec ion ha should be measu ed. This
esul ed in o e es ima ions in he CW me hod and unde es ima ions in he PW me hod. I
sys ema ic sampling is used, i is ad isable o es ablish he sampling in ensi y be o e andomizing
he posi ion along he s em o he i s disk o log o be measu ed. In he case o he PW me hod, i
is no ecommended o ake only one sample log pe ee, and he sample should be spli along
s em in an a emp o ep esen he a e age basic densi y, which usually occu s a a ela i e heigh
o 30-35% along he s em.
INDEX AND ABSTRACT
ix
The biomass equa ions we e i ed by seemingly un ela ed eg ession, wi h co ec ions o
he e oscedas ici y ca ied ou by weigh ed i ing. Diame e a b eas heigh was he bes
explana o y a iable, and he inclusion o heigh did no imp o e he accu acy o es ima ion, excep
o he wood componen . The inclusion o c own a iables imp o ed he p edic i e abili y o c own
ac ions, inc easing he accu acy o es ima ing hick b anches (by 10.8%), wigs (by 19.1%) and
lea es (by 17.3%). The biomass o each ac ion dec eased in he ollowing o de : wood > ba k >
hick b anches > dead b anches along he s em > lea es > hin b anches > wigs. The changes in
hese pe cen ages wi h diame e classes and he p edic i e abili y o he i ed equa ions we e also
s udied.
De elopmen o s and le el models o es ima ing biomass yield, o al ene gy and ca bon
seques a ion in Eucalyp us globulus and Eucalyp us ni ens plan a ions is desc ibed in Chap e IV
o i s o a ion s ands es ablished a he usual ange o ini ial o es densi ies in sou h-wes e n
Eu ope. The imbe olume, o al abo eg ound biomass, logging esidue biomass, c own biomass,
ca bon in abo eg ound biomass and soil o ganic laye , ene gy in abo eg ound biomass, ene gy in
logging esidue biomass and usable cellulose yield we e ep esen ed in he o m o isolines ( aking
mo ali y in o accoun ) and plo ed agains dominan heigh .
These a iables we e calcula ed and compa ed wi h p e iously published da a on wo
sil icul u al op ions o sho o a ion o es y, one des ined o bioene gy p oduc ion and he o he
consis ing o he s anda d sil icul u e egime applied o bo h species in sou he n Eu ope,
conside ing he a e age si e index o each. Yield le els we e highe in Eucalyp us ni ens han in
Eucalyp us globulus o all a iables, because o as e diame e inc emen a simila densi ies. The
o al yield in e ms o biomass was 13.9-14.6 Mg ha-1 y -1 o Eucalyp us globulus and 20.4-21.5
Mg ha-1 y -1 o Eucalyp us ni ens. The ene gy in abo eg ound biomass anged be ween 233-245
GJ ha-1 y -1 o Eucalyp us globulus and 345-364 GJ ha-1 y -1 o Eucalyp us ni ens; he ca bon
accumula ion a e in abo eg ound biomass and soil o ganic laye was 6.9-7.2 Mg ha-1 y -1 o
Eucalyp us globulus and 12.7-13.5 Mg ha-1 y -1 o Eucalyp us ni ens, and usable cellulose was
5.7-5.9 Mg ha-1 y -1 o Eucalyp us globulus and 9.0-10.1 Mg ha-1 y -1 o Eucalyp us ni ens.
Simula ed o a ions we e longe han he a e age leng hs conside ed o sho o a ion woody
c ops. This has some posi i e e ec s, such as highe wood:ba k a ios and la ge a e age ee
sizes. I was ound ha 50% inc emen s in he ini ial densi y esul in only ma ginal inc emen s in
biomass and usable cellulose yields. The densi y managemen diag ams cons uc ed can be used
as a powe ul ool o managemen o eucalyp plan a ions wi h a mul ipu pose objec i e (pulp o
solid imbe p oduc ion, ossil uel subs i u ion o ca bon seques a ion).
The applica ion o calo ime y and he mal analysis as no el echniques o elucida e how
a o es a ion a ec s he na u e o SOM and soil mic obial me abolism is desc ibed in Chap e V.
The echniques we e applied o s udy he SOM dynamics in wo s ands a o es ed wi h Pinus
adia a and Eucalyp us globulus, es ablished on pas u es in a humid empe a e egion. Resul s o
he mal analysis and calo ime y we e compa ed wi h hose ob ained by solid s a e nuclea
magne ic esonance, which is o en used o examine changes in chemical SOC s abili y.
CHAPTER 0
x
The applica ion o di e en ial scanning calo ime y and solid s a e nuclea magne ic esonance
e ealed ha he SOM comp ised ca bohyd a es, ca bonyl/ca boxyl g oups, alipha ic componen s
and a oma ic ca bon in he i s yea s o he o a ion. All hese ac ions became deg aded a e
a o es a ion. The deg ada ion was moni o ed by calo espi ome y, which p o ided he
calo espi ome ic a io o he soil basal me abolism, oge he wi h he ac i e biomass and he
me abolic quo ien . These indexes p o ed o be sensi i e pa ame e s ha p o ided in o ma ion
abou changes in he pa e n o mic obial me abolism in esponse o changes in he na u e and
edox s a e o he ca bon subs a es, demons a ing deg ada ion o he a oma ic and alipha ic
o ganic ma e ac ion. The echniques we e able o dis inguish di e ences in SOM dynamics in
he wo ypes o s ands, a ibu able o he di e en de elopmen o unde s o y ege a ion and li e
composi ion.
A comp ehensi e s udy was ca ied ou conside ing he ca bon sink e ec in biomass, soil and
wood p oduc s, he subs i u i e e ec o bioene gy, and pa icula condi ions o he o es indus y
in sou he n Eu ope, as desc ibed in Chap e VI. The CO2Fix model was pa ame e ized by using
he yield models, lea and b anch u no e a ios de i ed om he plo s es ablished and egion-
speci ic pa ame e s o p oduc s and biomass. Valida ion was ca ied ou o he biomass and he
soil module wi h plo -speci ic clima e da a ob ained om a ne wo k o 120 plo s. Resul s showed
s ong bias in SOC es ima ion, which was a ibu ed o o e es ima ion o he decomposi ion a es
in soil compa men s. Sligh bias in he ca bon biomass es ima ion was also obse ed when yield
models speci ic o o es land we e used o simula e a o es a ion on o me pas u e land.
As ega ds he sensi i i y, he Yasso model was ound o be s ongly obus o lea , oo and
b anch u no e . The woodchip p oduc ion al e na i e yielded highe ca bon s ock in biomass and
p oduc s, as well as in bioene gy subs i u ion e ec , han he sawn-wood p oduc ion al e na i e.
Ne e heless, he sawn-wood al e na i e was he mos e ec i e as ega ds he ca bon s ock in he
soil. Si e index had an impo an e ec o all species, al e na i es and compa men s, and he
mi iga ing e ec s on clima e change inc eased wi h si e index. Ha es ing clea cu ing and hinning
slash o bioene gy use led o a sligh dec ease in he soil ca bon equilib ium, bu signi ican ly
inc eased he mi iga ing e ec h ough bione gy use.

INDEX AND ABSTRACT
xi
0.3. Resumen
El cambio climá ico es hoy en día uno de los p oblemas ambien ales más p eocupan es a
ni el mundial. Es causado po el denominado e ec o in e nade o, debido en úl imo é mino a la
libe ación de can idades ingen es de gases de e ec o in e nade o, pa icula men e CO2. El sec o
ene gé ico es el que ac ualmen e más con ibuye al e ec o in e nade o, aunque el cambio de uso
del suelo debido a la de o es ación ambién iene una ele ada impo ancia. A pesa de las
endencias obse adas en las zonas opicales, donde g andes supe icies de bosque na i o
con inúan siendo de o es adas, los cambios de uso del suelo en Eu opa y Ame ica del no e an
en la di ección con a ia. Es e e ec o ha sido acele ado en pa e debido a la pues a en ma cha de
la Di ec i a EU 2080/92 de e o es ación de ie as ag a ias, la cual de i ó en una g an supe icie
de e enos e o es ados en el no e de España en e 1992 y 2006. Es as e o es aciones ue on
ealizadas mayo i a iamen e con especies de c ecimien o ápido, undamen almen e Eucalyp us
globulus Labill., Eucalyp us ni ens (Deane & Maiden) Maiden y Pinus adia a (D. Don), y
es ablecidas en su mayo ía sob e p ade as.
Los acue dos in e nacionales sob e educción de emisiones de ca bono pe mi en a los países
i man es la compensación de emisiones de CO2 median e acumulación en sumide os
econocidos como al. Sin emba go, hay una ele ada ince idumb e asociada a la es imación de la
can idad de ca bono secues ada en los sis emas o es ales, p incipalmen e en algunos
compa imen os conc e os como po ejemplo el suelo mine al. La ince idumb e es aún mayo en
sis emas que, as un cambio de uso, aún no han alcanzado el equilib io, po lo que el es udio de
la e olución del ca bono median e la me odología habi ual, suponiendo cambios de s ock en el
es ado de equilib io, pod ía aca ea impo an es e o es en la es imación.
Aunque la es imación del ca bono en la biomasa a bó ea es ela i amen e sencilla, la
es imación en o os compa imen os, como po ejemplo el suelo, es mucho más complicada y
iene asociada una mayo ince idumb e. Es e es el mo i o de que la mayo ía de los es udios de la
dinámica del ca bono en el suelo es án basados en modelos. Sin emba go, la e aluación empí ica
es necesa ia pa a es udios más consis en es, y p opo ciona in o mación aliosa pa a alidación
de modelos eco isiológicos así como pa a el desa ollo de modelos empí icos. Sin emba go, la
medida di ec a del ca bono en el suelo es labo iosa y los esul ados son al amen e a iables,
p o ocando que a menudo no sea posible ob ene esul ados concluyen es debido a la al a
a iabilidad. Además, los cambios en el ca bono en el suelo son di íciles de es ima debido a que
los p ocesos son ela i amen e len os, y a que hay o as a iables ex e nas que a ec an a su
e olución. En es e sen ido, el diseño expe imen al median e c onosecuencias combinadas con
pa celas pa eadas puede se ú il pa a con e i di e en as espaciales en di e encias empo ales, al
mismo iempo que pe mi en co egi endencias locales debido a la al a a iabilidad espacial de la
a iable de in e és, pe mi iendo e alua la e olución del ca bono a escala coma cal.
CHAPTER 0
xii
El ca bono en la biomasa a bó ea suele es ima se median e ecuaciones de biomasa, las
cuales se les supone una mayo p ecisión que los ac o es de expansión de biomasa. Sin
emba go, la es imación de la masa seca de los pies ipo que se emplea án en el desa ollo de las
ecuaciones de biomasa es posible que p esen e algún p oblema median e las me odologías en
uso. Además, el in e és c ecien e en ap o echa acciones de biomasa de copa pa a usos
ene gé icos, así como la necesidad de su es imación pa a es udios nu icionales y ecológicos,
lle a a la necesidad de dispone de modelos p ecisos pa a la es imación de las acciones de
copa. La inclusión de a iables de copa como explica i as en las ecuaciones de biomasa puede
lle a al desa ollo de modelos más p ecisos que los basados únicamen e en a iables de us e.
La p oducción ene gé ica de una plan ación es á habi ualmen e exp esada en é minos de
olumen o peso seco de made a, mien as que el e ec o de subs i ución de ca bono debido al uso
bioene gé ico de los p oduc os o es ales suele es a exp esado en é minos de ene gía, o
oneladas equi alen es de pe óleo. La can idad de ene gía ob enida po cada unidad de biomasa
depende del p oceso de ans o mación, lo que al inal lle a a que la es imación de la can idad de
ene gía se haga en unción del olumen en pie o de la biomasa y la aplicación de los ac o es
co espondien es. La exis encia de modelos especí icos pa a la es imación de la p oducción
ene gé ica en unción del es ado de desa ollo de la masa puede e i a la conca enación de
e o es en la es imación, y al mismo iempo pe mi i la compa ación di ec a de la p oducción
ene gé ica de a ias al e na i as sil ícolas o de di e en es especies.
El p ime paso en el es udio la e olución del ca bono en el suelo as un cambio de uso es la
e aluación del cambio de s ock. Sin emba go, la es abilidad de los compues os o gánicos del
suelo mine al a ía as el cambio de uso. Debido a que las écnicas adicionales pa a su
es imación son labo iosas y ca as, la pues a a pun o de écnicas que pe mi an abaja con un
g an olumen de mues as, y a un cos e azonable, se á de g an ayuda pa a es udios de
modelización de la es abilidad de la ma e ia o gánica del suelo. Ello cob a mayo impo ancia
cuando se equie e una ele ada esolución empo al o cuando se p e ende hace es imaciones a
g an escala, pa a lo cual es necesa io analiza una ele ada can idad de mues as.
Cuando se e alúa el e ec o de mi igación conjun o del sec o o es al, se han de conside a
odos los compa imen os en los que el ca bono se puede encon a e enido. Ello incluyen los
p oduc os que se gene an el los bosques debido a las co as de made a u o os p oduc os,
aunque no es á cla o aún como es os an a se enidos en cuen a en los acue dos in e nacionales
de educción de emisiones. Las écnicas más habi uales en es os es udios son los modelos
mecanís icos, como po ejemplo el CO2Fix, el cual pe mi e la es imación del e ec o de mi igación
de a ias al e na i as sil ícolas conside ando odos los compa imen os en los que el ca bono se
puede encon a e enido en los sis emas o es ales. Sin emba go, son escasos los es udios en
los que se han e aluado los esul ados ob enidos con es e ipo de modelos en las condiciones del
su de Eu opa.
El p incipal obje i o de es a Tesis Doc o al es la dise ación ace ca de la modelización y la
es imación de la acumulación de ca bono en sis emas o es ales. Pa a ello se han conside ado
INDEX AND ABSTRACT
xiii
odos los ni eles de es imación: á bol indi idual, odal y paisaje. El es udio ha cen ado en el
es udio de un p oceso dinámico, como es la a o es ación de pas izales en el no e de España. En
los dis in os capí ulos de la p esen e Tesis se han desa ollado y mejo ado he amien as pa a la
es imación de ca bono en sis emas o es ales. El es udio se ha cen ado en plan aciones
o es ales es ablecidas sob e an iguos pas izales sob e clima a lán ico del su de Eu opa, uno de
las zonas más p oduc i as de Eu opa.
El diseño expe imen al y los mé odos empleados en la ecolección de da os se esumen en
los siguien es pun os, co espondien es a dis in os capí ulos de la Tesis.
 Se es ableció una ed de 120 pa celas pa eadas (cada pa cela cons a de una an igua
p ade a y plan ación o es al es ablecida sob e la an e io , de di e en es edades),
es ablecidas a modo de c onosecuencia pa a las es especies mas habi uales en
a o es ación de e enos ag ícolas en el no e de España. Las pa celas pa eadas
ep esen a on el uso que o igina iamen e cub ía la o alidad de la pa cela (p ade a), y la
plan ación o es al es ablecida en pa e de la pa cela sob e el an e io uso. En cada
c onosecuencia, la densidad de ca bono po hec á ea ue e aluada en biomasa a bó ea,
man illo y suelo mine al has a 30 cm de p o undidad. La e olución del ca bono en el suelo
mine al y en el man illo debida a la edad anscu ida desde la a o es ación ue e aluada
median e análisis no pa amé ico, mien as que el ca bono en la biomasa aé ea ue
e aluado median e análisis de eg esión. El e ec o del u no de co a en el s ock de
ca bono pa a las e olución media de las pa celas medidas ambién ue e aluado.
 Se apea on un o al de 40 pies de E. ni ens, los cuales ue on some idos a análisis
des uc i o pa a e alua su peso seco. Los pies ue on di ididos en los siguien es
componen es: made a, co eza, amas g uesas, amas inas, amillos, hojas y amas
secas en el us e. Pa a e alua la masa seca de made a se empleó una in ensidad de
mues eo muy ele ada, que pe mi ió e alua el e ec o de és a en la es imación de la masa
seca de made a del á bol ipo cuando se aplica la me odología de a io ype es ima o s.
Se e alua on dos me odologías di e en es: pesado comple o del á bol en e de y
es imación de la masa seca median e discos omados sis emá icamen e a lo la go del
us e pa a de e mina la humedad (CW), y cubicado comple o del us e y es imación de la
masa seca median e la es imación de la densidad básica (PW). Además, se p obó el
ajus e de algunas a iables de copa como p edic i as en las ecuaciones de biomasa. La
capacidad de las ecuaciones desa olladas pa a la es imación de la p opo ción de las
dis in as acciones de biomasa ue e aluada pa a dis in as clases dimensionales.
 Se desa olla on modelos es á icos de c ecimien o pa a las dos especies de eucalip o
es udiadas, pa a lo que se midie on 15 pa celas adicionales pa a E. globulus y 36 pa a E.
ni ens, odas ellas es ablecidas sob e suelo o es al. Pa a el desa ollo de los modelos, se
u ie on en cuen a los lími es máximos de densidad debido al au ocla eo así como o as
limi aciones dimensionales de i adas de la posibilidad de cosecha median e maquina ia
con encional. Los modelos pe mi ie on e alua el e ec o de dos densidades iniciales en la
CHAPTER 0
xi
p oducción ene gé ica e aluada median e a ios indicado es, así como la acumulación de
ca bono en dis in os compa imen os pa a las dos especies de eucalip o conside adas.
 Va ias mues as conside adas como ep esen a i as de la e olución media de las
pa celas de E. globulus y P. adia a ue on analizadas median e calo ime ía y análisis
é mico, como écnicas ecien es pa a la e aluación del e ec o de la a o es ación de
e enos ag ícolas abandonados sob e la na u aleza de la ma e ia o gánica del suelo y del
me abolismo mic obiano. Los esul ados ue on compa ados con los ob enidos median e
una écnica bien con as ada pa a la e aluación de la na u aleza de la ma e ia o gánica, la
esonancia magné ica nuclea en es ado sólido. La aplicación de las dos écnicas pe mi ió
la es imación de la na u aleza de los cambios en la composición de la ma e ia o gánica de
los suelos as el cambio de uso de pas izal a plan ación o es al, y puso de mani ies o la
capacidad de la calo ime ía y el análisis é mico pa a di e encia g upos de compues os
de la ma e ia o gánica del suelo.
 El modelo mecanís ico CO2Fix ue pa ame izado con los da os ob enidos en los
apa ados an e io es y con da os adicionales ecopilados del sec o o es al en el no e de
España espec o al des ino indus ial de los p oduc os po especie y endimien o en la
ans o mación. La pa ame ización del modelo CO2Fix ue alidada pa a las condiciones
desc i as en el p esen e es udio con los esul ados ob enidos en las 120 pa celas de los
apa ados an e io es, donde el ca bono en biomasa, man illo y suelo mine al ue e aluado
median e medición di ec a. Una ez pa ame izado el modelo, se e aluó el e ec o de
mi igación de ca bono en dis in os compa imen os pa a dos al e na i as sel ícolas y cada
una de las especies es udiadas.
Respec o a la e olución del ca bono as el cambio de uso de p ade a a plan ación o es al
(Capí ulo II), la acumulación media de ca bono en biomasa y suelos pa a el o al de las pa celas
de cada especie osciló en e 8.7-14.6 Mg C ha-1 año-1 (Eucalyp us ni ens > Eucalyp us globulus >
Pinus adia a), y la con ibución del suelo (man illo + suelo mine al) sob e el o al osciló en e
8-18% (Eucalyp us ni ens > Pinus adia a> Eucalyp us globulus). El clima emplado-húmedo y la
ex u a del suelo anco-a enosa a o ecie on las ele adas pé didas de ca bono en el suelo en los
ho izon es supe iciales du an e los p ime os 10 años as el cambio de uso. Las pé didas ue on
debidas en pa e a los ele ados con enidos de ma e ia o gánica en el uso del suelo p e io. Las
ele adas pé didas de ca bono obse adas en las pa celas de P. adia a (26% del con enido inicial
de ca bono, en e al 19,5% de pé dida en las pa celas de ambos eucalip os) ue on a ibuidas a la
meno asa de ans e encia de ma e ia o gánica esca al suelo mine al, debido a una meno asa
de descomposición del man illo y a una meno inco po ación de li e p oceden e de las aíces de
las especies he báceas. Es e úl imo ac o ue debido a di e encias en la somb a p oyec ada po
ambos g upos de especies, lo que al inal de i ó en di e encias mic oclimá icas bajo cubie a. Las
condiciones climá icas a o ecie on el ápido c ecimien o de la biomasa a bó ea y
consecuen emen e del apo e de ma e a o gánica al suelo mine al.
GENERAL INTRODUCTION AND OBJECTIVES
3
1. Gene al in oduc ion and objec i es
1.1. Clima e change and he o es sec o
1.1.1. Clima e change, a global p oblem
Almos he en i e scien i ic communi y now accep s he e idence ha he clima e is changing.
This e ec has been epo ed in ela ion o he end in annual empe a u es in he las 30 yea s
(T enbe h & Josey, 2007), and on a longe imescale in he las cen u y (Jones & Mobe g, 2003),
and in he las 1000 yea s (Jones e al., 2001). Al hough he e ha e been examples o na u al
clima e oscilla ions h oughou he Ea h’s his o y, he cu en e ec is a ibu ed o an h opogenic
ac i i y (IPPC, 2001; G ace, 2004). The wo main easons o clima e change a e inc easing
emissions o g eenhouse gases (GHGs) and ae osols, and land use change, bo h o which cause
changes in a mosphe ic empe a u e (Hough on e al., 1990) as a esul o he so called
g eenhouse e ec (GE).
The main GHGs a e wa e apou , CO2, CH4 and N2O. Emissions o GHGs used o be
exp essed in e ms o CO2-equi alen because CO2 alone con ibu es mo e han 30% o he o al
g eenhouse e ec in he a mosphe e, 56% o he an h opogenic adioac i e o cing (Hansen &
Lacis, 1990), mo e han 82% o o al emissions a Eu opean le el (IPPC, 2007), and also because
i can be cap u ed h ough biological p ocesses. Plan s, as au o ophic o ganisms, ans o m
ino ganic compounds in o o ganic issues, consuming CO2 in he p ocess. Releases ia espi a ion
and seques a ion by biomass g ow h we e in equilib ium un il he beginning o he indus ial age,
when huge amoun s o he sys em ca bon (C) was eleased as a esul o inc eased bu ning o
ossil uels ca ied ou in esponse o inc eased ene gy demands (Foley e al., 2005).
Some scien is s hink ha clima e change is i e e sible (Solomon e al., 2009). None heless,
e en g ea e inc eases in he a e age annual ai empe a u e will occu unless mi iga ion policies
a e adop ed (Meehl e al., 2007). The de elopmen o adap a ion s a egies and e alua ion o he
p edic able impac s on each sec o as ega ds he new si ua ion a e wo o he mos ac i e
esea ch lines a he momen (Campioli e al., 2009). The e a e se e al ways o educing CO2
emissions by he amoun s equi ed by in e na ional ag eemen s, bu hese can be summa ized in
wo se s o ac ions: inc easing he C sink, and educing C emissions.
Wo ldwide, GHGs emissions a e mainly ela ed o ene gy use (63%), p edomina ed by
elec ici y powe plan s, indus y and anspo (Fig. 1.1). Reduc ion in GHGs emissions he e o e

CHAPTER I
4
equi es a change in ene gy supply o al e na i e enewable ene gy sou ces. Al hough he e a e
a ious CO2- ee al e na i es o powe and indus y ene gy supplies (i.e. nuclea , wind, hyd aulic),
as ega ds anspo , he use o bio uels has ecei ed ex ensi e a en ion because a p esen he e
a e no o he CO2- ee al e na i es a ailable wi h he echnology in use (Ful on e al., 2004). Some
au ho s indica e ha o a signi ican mi iga ion o ossil uel emissions, e y la ge a eas o
c opland would be equi ed o p oduce su icien amoun s o bio uel o anspo needs (Righela o
& Sp acklen, 2007), which may lead o displacemen o ag icul u al p oduc ion and cause
addi ional land-use change, inally leading o ne inc eases in GHGs emissions (Sea chinge e al.,
2008; Melillo e al., 2009). In his sense, only con e sion o woody biomass may be compa ible
wi h e en ion o o es ca bon s ocks (Ki schbaum, 2003; Tilman e al., 2006; Righela o &
Sp acklen, 2007).
In Spain, 80% o GHGs emissions a e de i ed om he ene gy sec o , and enewable ene gies
ha e been conside ed as an impo an al e na i e o educing emissions, wi h biomass ha ing a
neu al emission e ec . The 2005-2010 Renewable Ene gy Plan (PER) in Spain aimed a a 12%
con ibu ion o enewable esou ces o p ima y ene gy consump ion by 2010. Howe e , he
cu en si ua ion clea ly shows ha biomass is he leas well de eloped among he enewable
ene gies in Spain. The sha e o o es biomass is di icul o calcula e, al hough i is clea ha
ecen ini ia i es o new powe plan s a e mainly linked o he use o o es and ag icul u al
indus y esidues, and ha o es ene gy c ops (sho o a ion coppice) would be impo an wi hin
he g oup o ene gy c ops. One o he key elemen s o he p e ious poin s is Royal Dec ee RD
661/2007, which es ablishes he g an sys em o al e na i e ene gy p oduc ion. The Dec ee
alloca es a la ge po ion o he incen i es o powe plan s ha u ilise biomass om ene gy c ops.
Indus y
Ene gy supply
Indus y
Was e and was ewa e
Buildings
De o es a ion
Ag icul u e
Global emissions by sec o
NON-ENERGY
EMISSIONS
Indus y
Ene gy supply
Indus y
Was e and was ewa e
Buildings
De o es a ion
Ag icul u e
Global emissions by sec o
Indus y
Ene gy supply
Indus y
Was e and was ewa e
Buildings
De o es a ion
Ag icul u e
Global emissions by sec o
NON-ENERGY
EMISSIONS
Figu e 1.1. Global g eenhouse gases emissions by economic sec o . Sou ce: IPPC (2007).
Inc ease o e es ial sinks also lead o dec eases in he concen a ion o a mosphe ic CO2,
al hough he mi iga ing e ec o his op ion is limi ed. Non ene gy emissions accoun o up o 37%
o global emissions (Fig. 1.1), and a change in land use o o he s wi h mo e a ou able C balance
may pa ly mi iga e he g eenhouse e ec . Mo eo e , al e na i e managemen schemes o cu en
GENERAL INTRODUCTION AND OBJECTIVES
5
land uses may p o ide di e en C balances, and mus he e o e be in es iga ed (Malhi e al.,
2002).
1.1.2. In e na ional ag eemen s ega ding educ ion o GHG emissions
All adminis a ions and policymake s now acknowledge clima e change as one o he mos
impo an cu en en i onmen al p oblems, and se e al a emp s ha e been made o ob ain
in e na ional ag eemen o educing CO2 emissions. Inclusion o ca bon sinks in he global ca bon
budge was discussed a he Uni ed Na ions F amewo k Con en ion on Clima e Change
(UNFCCC) celeb a ed in Rio de Janei o (1992). Howe e , i was a he Kyo o mee ing (UNFCCC,
1997) ha he UNFCCC limi ed GHGs emissions, aking as a baseline o accoun ing he
emissions le els in 1990; i was also ag eed ha emissions could be compensa ed h ough sinks.
This documen ecognizes wo main al e na i es o emissions compensa ion in he Land Use,
Land Use Change and Fo es y (LULUCF) sec o o indus ialized coun ies, depending on
whe he he ac ions ook place wi hin hei own e i o y (A . 3.3, 3.4 and 6) o in o he non-
indus ialized coun ies (A . 12). Fo ac ions wi hin hei own bo de , he Kyo o P o ocol (KP)
allows coun ies included in Annex I he ollowing ac i i ies o mee he equi emen s o he KP:
 A icle 3.3, o use “ne changes in g eenhouse gas emissions by sou ces and emo als by
sinks esul ing om di ec human-induced land-use change and o es y ac i i ies, limi ed
o a o es a ion, e o es a ion and de o es a ion (ARD) since 1990” (UNFCCC, 1997).
 A icle 3.4: “ o es managemen (FM), c opland managemen (CP), g azing land
managemen (GM) and e ege a ion (RV) a e eligible land-use, land-use change and
o es y ac i i ies” (UNFCCC, 2001).
 A icle 6: “ ans e o, o acqui e om, any o he such pa y educ ion uni s esul ing om
p ojec s aimed a educing an h opogenic emissions by sou ces o enhancing
an h opogenic emo als by sinks o g eenhouse gases in any sec o o he economy,
p o ided ha (…) any such p ojec p o ides a educ ion in emissions by sou ces, o an
enhancemen o emo als by sinks, ha is addi ional o any ha would o he wise occu ”
(UNFCCC, 1997), which is known as join implemen a ion (JI).
 A icle 12, Annex I coun ies a e allowed o acqui e om non-Annex I coun ies ce i ied
Emissions Reduc ion Uni s (ERUs), h ough he so called Clean De elopmen Mechanism
(CDM), which p o ides ha C emo al p ojec s a e “addi ional o any ha would occu in
he absence o he ce i ied p ojec ac i i y” (UNFCCC, 1997), and is limi ed o
a o es a ion and e o es a ion ac i i ies o he i s commi men pe iod (UNFCCC, 2001).
JI and CDM a e equi ed o conside a baseline o he ce i ied emission educ ions, in o he
wo ds he e e ence C le el wi h espec o gains o losses mus be es ima ed, and o ag icul u al
ac i i ies (CM, GM, and RV), ne -ne accoun ing is equi ed, which consis s o conside ing “ne
emissions o emo als o e he commi men pe iod less ne emo als in he base yea , imes i e”.
CHAPTER I
6
In subsequen mee ings (UNFCCC, 2002; UNFCCC, 2003) he ins uc ions o GHGs in en o ies
in he LULUCF sec o we e de ined. This a angemen de ines he me hodology, he de aul alues
and he pools ha mus be conside ed in o es GHGs in en o ies, as ollows: li e abo e and
belowg ound biomass, li e , dead ees and soil o ganic ma e . Ca bon in o es p oduc s canno
he e o e be conside ed in ca bon accoun ing calcula ions (UNFCCC, 2002).
The esul s o he las mee ings o he Uni ed Na ions Clima e Change Con e ences (COP)
celeb a ed in Copenhagen (COP15, 2009) and Cancun (COP16, 2010) a e ambi ious in ega d o
GHGs educ ion and de e ed he o ce pe iod o KP. Howe e , he cu en economic c isis, he
gene alized dependency o ossil uel ene gy, and he pe missi eness wi h de eloping coun ies
wi h high emissions a es, makes compliance o he in e na ional ag eemen s on emission
educ ions di icul . GHGs emissions inc eased by a eco d amoun in 2010, o he highes ca bon
ou pu in his o y (30.6 Tg), acco ding o he In e na ional Ene gy Agency, pu ing hopes o holding
global wa ming a sa e le els all bu ou o each.
To al emissions inc eased be ween 1990 and 2008 in Spain by on a e age 47.8%; inclusion o
LULUCF supposes a educ ion o 15.1 poin s as ega ds he la e igu e (UNFCCC, 2010). Fo he
pe iod 2008-2012, Spain is commi ed o inc easing emissions by 15% ela i e o he base yea
(1990), which is included in he emission allowance ading scheme wi hin he EU, i.e. global
educ ions in emissions o 8%. None heless, he p e isions o he go e nmen (II Assigna ion Plan)
conside an inc ease o 37% he mos likely es ima ion.
The Spanish Clima e Change and Clean Ene gy S a egy (EECCEL) conside s ha he
inc easing end o GHG emissions in he 1990-2008 pe iod co esponded o apid, sus ained
economic g ow h, and o an inc ease in popula ion in ecen yea s. The e o made by Spain in
ma e s o Ene gy Sa ing and E iciency was insu icien , bu he epo also shows ha he pe
capi a emissions eached an a e age o app oxima ely EU-15. The EECCEL s a es ha he a ge
es ablished by he Go e nmen o he i e-yea pe iod 2008-2012 is ha Spain’s o als do no
su pass a 37% inc ease ela i e o he emissions in he base yea . This ep esen s a di e ence o
22 pe cen age poin s wi h espec o +15%, 2% o which mus be ob ained by means o sinks, and
he emainde (20%) by means o lexible mechanisms (acquisi ion o ca bon c edi s). In o de o
each he said objec i e o +37%, he Na ional Alloca ion Plan (NAP) 2008-2012 equi es addi ional
measu es o ob ain educ ions o 27.1 M o CO2 eq. A Plan o U gen Measu es conside s
educ ions o 12.091 M CO2 eq y -1, so ha addi ional measu es a e s ill necessa y o p o ide
educ ions o 15.033 M CO2 eq y -1.
1.1.3. The ole o o es s and he o es -based sec o in clima e change mi iga ion
As p e iously epo ed, he main esea ch lines ega ding clima e change and he o es sec o
a e impac s, mi iga ion and adap a ion (Campioli e al., 2009). Mi iga ion is he ac ion aken o
educe he a mosphe ic concen a ion o GHGs in o de o p e en dange ous clima e change
(IPPC, 2007). Howe e , as GHGs mi iga ion alone is no su icien o p e en clima e change, we
GENERAL INTRODUCTION AND OBJECTIVES
7
mus be p epa ed o he possible impac s o inc eased empe a u es and changes in p ecipi a ion
egimes on o es s.
Se e al impac s a e cu en ly unde s udy; mos o hese a e ela ed o change in o es
p oduc i i y, abio ic and bio ic dis u bances, and species mig a ion and ex inc ion (Thuille , 2003;
Thomas e al., 2004; Ba is i e al., 2005; Blennow & Olo sson, 2008; Lindne e al., 2010;
McMahon e al., 2010). The suscep ibili y o o es s o hese impac s depends on he inhe en
adap i e capaci y o ees and o es ecosys ems (Ham ick, 2004; Thuille e al., 2005) as well as
on he in ensi y and di ec ion o clima ic a iables. Adap a ion is adjus men in na u al o human
sys ems in esponse o ac ual o expec ed clima ic s imuli o hei e ec s (IPPC, 2007).
The e a e se e al ways in which o es s and he o es -based sec o can con ibu e o
mi iga ing he g eenhouse e ec . In simpli ied e ms, he o es -based sec o can be seen o be
o med by he o es ecosys em, o es p oduc s, and ene gy om he o es s. Canadell & Raupach
(2008) indica ed ou o es managemen s a egies o mi iga ing GHGs emissions: (i) inc easing
he o es a ea h ough e o es a ion, (ii) inc easing he C densi y pe a ea, (iii) inc easing o es
p oduc use and ossil uel subs i u ion h ough bioene gy, and (i ) educing de o es a ion and
deg ada ion. Toge he hese p oposals can be summa ized as inc easing C s ock in all
compa men s in which o es s can con ibu e (biomass, soil, p oduc s), and gene a ing a s eam o
a oided emissions h ough bioene gy use.
Dec easing he o es a ea is one o he mos impo an ac o s as ega d elease o CO2, N2O
and CH4 o he a mosphe e (Shukla e al., 1990; Malhi e al., 2008). This is s ill occu ing in he
opics (Canadell & Raupach, 2008), whe eas he o es a ea is gene ally inc easing in empe a e
and bo eal egions (FAO, 2005). One o he mos e iden ways o mi iga ing clima e change
h ough he o es sec o is he e o e o inc ease o es a ea o main ain he a ea by slowing down
de o es a ion, al hough his is di icul because o es land in de eloping coun ies is being
ans o med o ag icul u e land o mee human eed equi emen s. In his con ex , he a ea co e ed
by o es plan a ions is expec ed o inc ease by 16-32% by 2030 ela i e o he le el in 2005
(es ima ed a 261 M ha, Ca le & Holmg en, 2009). Acco ding o hese au ho s, he highes
absolu e inc ease will ake place in Asia, whe eas he highes ela i e inc ease will occu in
Sou he n Eu ope.
O he ways o inc easing he C s ock a e o op imize managemen schemes ega ding C
seques a ion (Liski e al., 2001; Liski e al., 2002; Kaipainen e al., 2004; Canadell & Raupach,
2008). In adi ional o es y, managemen schemes conside wood supply o economic c i e ia,
and o he ypes o managemen schemes ha a ou be e C balance may no be compa ible wi h
adi ional managemen p ac ices (Lindne & Ka jalainen, 2007). Addi ional esea ch is he e o e
needed o e alua e he e ec o ac ual and po en ial managemen schemes on he di e en C
pools conside ed in he in e na ional ag eemen s (UNFCCC, 2002).
Finally, he las way in which he o es sec o can mi iga e clima e change is known as he
subs i u ion e ec . This in ol es he so-called a oided emissions, de i ed om consump ion o
ha es ed wood p oduc s (HWP), a he han o he p oduc s ha equi e consump ion o ossil
CHAPTER I
8
uels du ing hei ab ica ion. HWP a e no conside ed in global C budge s unless a coun y can
show ha i s long e m exis ing s ocks a e inc easing (UNFCCC, 2002), al hough he 26 h session
o he Subsidia y Body o Scien i ic and Technological Ad ice (UNFCCC/SBSTA/2007/4,
pa ag aphs 59-61) had in i ed pa ies in a posi ion o do so, o epo olun a ily on wood p oduc s
in hei na ional in en o ies. This is because he s ong e ec o HWP on he global ca bon cycle
due o he a oided emissions om sou ces ha ha e s o ed ca bon o housands o yea s.
The e o e, e en when he emissions om HWP a e immedia e (in he case o bioene gy), o when
he wood p oduc would ha e a longe li espan ( u ni u e, pape , e c.), he a oided emissions o
ob ain he same amoun o ene gy o o manu ac u e he al e na i e p oduc a e de i ed om a
pool ha has been s o ed o housands o yea s.
Keeping o es s a an in ense s age o g ow h may help maximize he supply o o es
p oduc s, and he e o e maximize he mi iga ing e ec , al hough his does no mean ha changes
om ma u e i gin o es s o plan a ions should be en isaged. Some s udies ha e shown he abili y
o old g ow h o es o cap u e C (Ca ey e al., 2001; P egi ze & Euski chen, 2004; Zhou e al.,
2006; Luyssae e al., 2008), and o he s udies ha e epo ed ha change om old-g ow h o es
o young as g owing o es does no esul in a posi i e ne C balance, e en i wood p oduc s a e
conside ed (Ha mon e al., 1990). Holding o es s a as g owing s ages implies in ense
managemen , which may inally lead o losses o soil o ganic ca bon (SOC), al hough he balance
is usually owa ds ne sink e ec s.
The igh agains clima e change may p oduce es ic ions, bu also oppo uni ies: mi iga ion
can educe ou ex e nal dependence on ossil uels and alle ia e en i onmen al p oblems, such as
u ban con amina ion. Land use planning can also be imp o ed and clean anspo sys ems
p omo ed.
1.2. The o es y sec o in no he n Spain and clima e change
mi iga ion
1.2.1. Fo es y, land-use change and ca bon seques a ion in Spain
The u al landscape unde wen a change du ing he las cen u y, mo i a ed by he change in
economic ac i i y. A he beginning o he 20 h cen u y, mos o he p ima y economic sec o was
based on ag icul u e and li es ock. The no mal de elopmen and mode niza ion o he p ima y
sec o we e held up by he ci il wa and he pos e io eco e y pe iod. F om he mid-1950s,
depopula ion o u al a eas led o huge abandonmen o land (Lasan a, 1996; La o el e al., 1998);
ag icul u e p oduc ion was concen a ed in he mos p oduc i e a eas, and less p oduc i e land
was abandoned o ans o med in o o es .

GENERAL INTRODUCTION AND OBJECTIVES
9
Du ing his ime he Spanish Go e nmen ini ia ed an ex ensi e a o es a ion p og am ac oss
he coun y, which led o in a huge a eas o land being a o es ed. In he pe iod 1940-1973, he
o al a ea a o es ed in Spain was 2306200 ha (Pemán Ga cía e al., 2009), and 48% o his
co esponded o a o es a ion o non o es land. The main objec i es o his policy we e o
inc ease he o es co e and o educe u al unemploymen . The mos commonly used species in
his ex ensi e a o es a ion p og am we e coni e ous species, because he land a ailable was he
leas p oduc i e land (Pemán Ga cía e al., 2009). As ega ds land p ope y, mos o his
a o es a ion in ol ed public land, al hough some in ol ed collec i ely owned land.
Mo e ecen ly (in 1992), he Eu opean Union implemen ed a policy o a o es o me
ag icul u al land (EEC 2080/92), which led o a o es a ion o app oxima ely 160000 ha o land in
no he n Spain (MAPA, 2006). Al hough he main aim o his policy was o educe ag icul u al
su pluses, he e ec on C s ock is s ill unde s udy. Li es ock p edomina es in he ag icul u al
sec o in he no h o Spain, he mos equen land use change was he e o e om pas u e o
o es land. Pas u e land was usually managed in o a ion wi h ape-seed, wi h inc easing
impo ance o he pas u e as abandonmen became s onge .
Finally, almos 3.0 M ha o land we e e o es ed in Spain in he las cen u y, o which a leas
1.4 M ha was non o es land, p edominan ly ag icul u al land (Pemán Ga cía e al., 2009). In 2005
he o al a ea co e ed by plan ed o es s in Spain was 1.4 M ha (Del Lungo, 2009). Because o he
peculia i y o his land use change, esea ch is equi ed o e alua e he e ec o his policy on he
global C sink.
The main objec i es o he Spanish o es -based sec o a e o inc ease he capaci y o CO2
seques a ion om he a mosphe e by wood s ocks, and o comply wi h he goal o compensa ing
2% o he base yea emissions by LULUCF. The ole o Spanish o es in clima e change mi iga ion
has been in es iga ed in speci ic s udies (B a o, 2007; Pa dos, 2010), which epo ed a alue o
670 M CO2 o ca bon s o ed in he abo eg ound biomass o ees, whe eas G acia e al., (2005)
epo ed a highe alue o 2050 M CO2 o a o al ca bon in o es s, wi h an annual ne inc ease in
seques a ion equi alen o 40 M . The balance be ween Na ional Fo es In en o ies IFN2 (1986-
1996) and IFN3 (1997-2006) has been s udied in de ail in some a eas (B a o, 2007) and he
alues o inc eased C (new o es s, g ow h o exis ing ees, ing ow h) and dec eased C ( elling,
na u al mo ali y) we e ound o lead o a ne inc ease o 54.6%.
This same sou ce o in o ma ion (IFN) shows ha in all egions Spanish o es s ha e ac ed as
C sinks du ing he 20 h cen u y, wi h a ne inc ease in he sink e ec in he pe iod 1990-1998
ela i e o he pe iod 1974-1987 (Rod íguez-Mu illo, 1999). Be ween he las wo in en o ies, he
o al amoun o C accumula ed in he abo eg ound biomass anged be ween 4.5 Mg C ha-1 o
Galicia (2.0 in he p e ious pe iod) and 1.1 Mg C ha-1 in Mu cia (0.27 in he p e ious pe iod). This
change is a ibu ed o he e o es a ions ca ied ou in Spain in he 1940s, and o mo e ecen
changes in land use, mainly in ag icul u al land, which led o an inc ease in he o es a ea as well
as in ca bon densi y (Rod íguez-Mu illo, 1999). Howe e , in hese es ima ions i is assumed ha
CHAPTER I
10
a o es ion on o me ag icul u al land ollows he same dynamics as seconda y successions o
e o es a ions, al hough his is s ill unde s udy.
1.2.2. The ee species s udied
The con ibu ion o o es plan a ions o he global wood supply is unques ionable. While o es
plan a ions ep esen ed less han 7% o global o es a ea wo ldwide in 2005 (FAO, 2005), in he
same yea hey sa is ied wo- hi ds o global indus ial oundwood needs (E ans e al., 2009). In
he no h o Spain, o es plan a ions also p edomina e in he o es indus y supply, and as
g owing ee species a e he mos commonly used in a o es a ion (Ál a ez, 2004). Pines and
eucalyp s a e he mos equen ly used species in o es plan a ions, and in plan a ions on o me
ag icul u al land, he mos commonly used ee species in no h-wes e n a e Eucalyp us globulus
(Labill), Eucalyp us ni ens (Dean & Maiden) Maiden and Pinus adia a (D.Don).
Eucalyp us globulus (Labill)
Eucalyp us globulus is na i e o sou h-eas e n Aus alia (Vic o ia) and he sou h coas o
Tasmania, whe e i g ows in he lowes zones o he island (0-550 m); he a e age p ecipi a ion in
he zone anges be ween 600 and 1500 mm, in a empe a e- ype clime. This species was i s
in oduced in Eu ope om Aus alia in 1863 (Ruiz de la To e e al., 1979), and nowadays is
dis ibu ed along he en i e coas o he A lan ic Ibe ian Peninsula. F os ole ance is he p incipal
cons ain o plan ing a ele a ions highe han 400-500 m. The ange o ain all in he a eas whe e
i has been in oduced is e y b oad, and he a e age alue o he No h and No hwes e n Ibe ian
Peninsula is highe han 1500 mm, which explains he good yields. One o he main p oblems o
his species as ega ds o es g ow h is disease a ack, which causes educed yield h ough
de olia ion a he young s age (Mycosphae ella spp. (O e o e al., 2007)), o a he adul s age
(Gonip e us scu ella us (Mansilla Vázquez, 1992)). Al hough se e al esis an clones o E. globulus
Mycosphae ella a e a ailable nowadays, in ec ion o he adul s ages by Gonip e us is mo e
di icul o manage.
Ini ially he species was widely used o mining imbe and a ange o o he uses. Nowadays,
eucalyp us imbe is mainly used o p oduce bleached pulp, al hough p oduc ion o ene gy c ops is
also a p omising managemen goal, because o he high p opo ion o cellulose in he imbe
(which can lead o high p oduc ion o bio-e hanol), and i s esp ou ing abili y. O he po en ial uses
unde s udy a e as high quali y sawn-wood (Nu o & Touza Vázquez, 2004), and also s uc u al
wood (Guai a & Ei as, 2007). The so-called chip indus y co e s he use o eucalyp imbe o pulp
p oduc ion, which is he main use o his species, because o i s a ou able speci ic consump ion
ela i e o o he species (Co e ill & Mac ae, 1997). Managemen o s ands o his pu poses s a s
wi h plan a ion densi ies be ween 1300 and 1400 s ems ha-1, and hinning is no ca ied ou . A e
he i s o a ion (13-16 yea s), se e al coppice o a ions a e expec ed un il new plan a ions a e
GENERAL INTRODUCTION AND OBJECTIVES
11
es ablished. In each coppice o a ion, sp ou selec ion is equi ed o main ain he sp ou densi y
cons an .
Eucalyp us ni ens (Dean & Maiden) Maiden
Eucalyp us ni ens is na i e o he sou h-eas o Aus alia, whe e i is discon inuously p esen in
he s a es o New Sou h Wales and Vic o ia. This species g ows na u ally a al i udes be ween 600
and 1600 m in he empe a e zone, wi h p ecipi a ions o be ween 750 and 1750 mm pe yea .
Moun ain blue gum ole a es absolu e minimum empe a u es o -10ºC in no h-wes e n Spain
(González-Río e al., 1997), and o 21-23ºC in he ho es mon h in i s egion o o igin (Boland e
al., 1980). Eucalyp us ni ens is one o he mos widely used plan a ion species wo ldwide in
empe a e cold egions, and co e ed mo e han 340000 ha in 2004 (INFOR, 2004). Expansion o
his species in no he n Spain began ecen ly; esea ch ials we e es ablished a ound 1950, and
comme cial plan a ions began in 1992 in no h-wes e n Spain. The eason o he success was he
possibili y o expansion in a eas ha we e oo cold o E. globulus, in addi ion o he high yield,
pes esis ance, and he ela i ely good wood p ope ies o he species.
In con as o he end obse ed o he species in Spain, he main des ina ion o E. ni ens
wood wo ldwide is he pulp indus y (INFOR, 2004). This is pa ly because o he good mechanical
p ope ies o E. ni ens pulp (Paz, 1999), bu also because o i s high yield. Ne e heless, he
speci ic consump ion o E. ni ens is highe han ha o E. globulus (Co e ill & Mac ae, 1997), and
he e a e some p oblems ela ed o pi ch, which cause pulp s ain. Ano he in e es ing p ope y o
E. ni ens is he calo i ic powe o i s was e and wood, which makes i sui able o ene ge ic
pu poses (Pé ez e al., 2008).
The mos common managemen scheme o E. ni ens in no he n Spain is plan ing a densi ies
o 1300-1400 s em ha-1, wi h no hinning. No coppice egimes a e applied in no h-wes e n Spain,
because he mos common p o enance used in e o es a ion in he egion (MacAlis e ), has li le
esp ou ing abili y (Sims e al., 1999b; Sims e al., 2001; Li le & Ga dne , 2003). The possibili y o
coppicing o o he p o enances in no he n Spain is s ill unde s udy. The e is some in e es in
p oducing sawn-wood wi h his species, and hinning and p uning schemes a e he e o e unde
s udy. Ano he cu en impo an line o esea ch is ene ge ic plan a ions, al hough he species
does no g ow pa icula ly well a high densi ies (Sims e al., 1999a; Sims e al., 2001).
Pinus adia a (D.Don)
Pinus adia a is na i e o a small a ea on he wes coas o No h Ame ica (Swan on,
Mon e ey and Camb ia in Cali o nia, and Guadalupe and Ced os in Mexico), bu is one o he
mos commonly used species in a o es a ion h oughou he wo ld, and also he mos commonly
used exo ic coni e o e o es a ion in he wo ld (La e y, 1986) and in Spain. The species was
in oduced in Spain in abou 1850, and hence o h i s co e inc eased h oughou empe a e-
clima e Spain (Galicia, As u ias, Can ab ia and he Basque Coun y). The success o expansion
was due o i s as g ow h in empe a e-clima e egions, he wood quali y and he plas ici y.
CHAPTER I
12
The main des ina ion o P. adia a wood is as sawn-wood, bu also as woodchip o he
chipboa d indus y. Managemen schemes o his species in he egion depend on he wood
des ina ion. Fo he sawn-wood indus y, managemen consis s o plan ing a 1200-1400 s ems
ha-1, wo hinnings, and a hi d in cases whe e high alue p oduc s a e he p oduc ion objec i e
and si e quali y is la ge enough. P oduc s om he i s hinning a e usually used in he chipboa d
indus y o o bioene gy, and only a ew ees (400 s ems ha-1) emain s anding a he end o he
o a ion, which in his case is 35-40 yea s. Two p unings a e equi ed o ensu e wood quali y a he
end o he o a ion. On he o he hand, managemen o woodchip o use in he chipboa d indus y
s a s wi h highe densi ies, and he o a ions a e sho e han o sawn-wood.
1.3. Managemen ools and me hods o ca bon in en o y and
e alua ion o mi iga ion e ec s in o es s
The e a e se e al ways o moni o ing ca bon s ocks and he mi iga ion e ec in o es
ecosys ems, bu all can be classi ied in wo main g oups: (i) me hods based on measu ing he
sys em C luxes (FA), and (ii) me hods based on measu ing changes in C s ock (SA) (Ney e al.,
2002; Hough on, 2003; Lindne & Ka jalainen, 2007; Dias e al., in p ess). The main di e ences
be ween he di e en ways o es ima ing he s ock and he mi iga ion e ec s a e ha C in he FA
app oach is e alua ed om a dynamic poin o iew (exchange a e), whe eas C in he SA
me hodology is e alua ed om he s a ic poin o iew (s ock). Wi h he i s app oach a en ion is
ocused on he speci ic p ocess unde s udy, mo e impo ance is gi en o he exchange o C in he
sys em o be ween wo pools in he same sys em (i.e. soil and li ing biomass, o al sys em and he
a mosphe e, e c.). In he second app oach, mo e impo ance is gi en o he inal esul o he
physiological p ocess, which in he end is he accumula ion o C in he sys em. Since he FA
app oach is sensi i e o sho - e m changes in he en i onmen al condi ions, e oneous
conclusions could be eached om his me hod unless a ep esen a i e empo al ime se ies is
measu ed. Mo eo e , he ini ial alue mus be gi en o assessmen o he inal s ock, and he SA
me hodology mus be applied anyway. The SA app oach is he e o e he mos commonly used
me hod o in es iga ing changes in o es sys ems and o es ima ing mi iga ion e ec . Howe e ,
he e is s ill some unce ain y as ega ds ce ain aspec s o his me hodology, as de ailed below.
O he me hods a e used almos exclusi ely o es ima ing he mi iga ion e ec associa ed wi h
ha es ing and wood p oduc s, hese a e he me hodologies based on measu ing p oduc ion (PA)
(B own e al., 1999; Dias e al., in p ess).
Depending on he me hodology, all app oaches may be classi ied as di ec measu emen o
es ima ion h ough p e iously de eloped models. Al hough di ec measu emen is he mos eliable
way o es ima ing he C s ock in o es sys em, his me hod is ime consuming and expensi e when
an adequa e eplica ion is applied. A modelling app oach is he e o e usually used o de e mine he
GENERAL INTRODUCTION AND OBJECTIVES
19
he s em o de e mine he d y mass om he a e age mois u e con en and he o al esh weigh ,
o om he s em olume and he a e age basic densi y. S udies in which biomass equa ions a e
de eloped a ee le el do no usually p o ide in o ma ion abou he exac posi ion o he samples
aken and hei dis ibu ion. Mo eo e , in such s udies samples a e usually aken sys ema ically
om s ump heigh , because o he accessibili y o his posi ion and ha ac ha no comme cial
logs a e was ed. Howe e , he e ec o his on he es ima ion o he d y mass is s ill no clea .
The ques ions add essed in Chap e IV a e:
 Wha is he e ec o sampling in ensi y on he d y mass es ima ion o sampling ees when
sys ema ic sampling and a io ype es ima o s a e applied?
 Do c own a iables imp o e he accu acy o c own ac ion biomass equa ions?
 Wha is he abili y o biomass equa ions o p edic he p opo ion o biomass ac ions?
 Is he e a sys ema ic bias inhe en in he bole sampling p ocedu e?
1.4.3. A e Eucalyp us plan a ions sui able o ca bon seques a ion and bioene ge ic
pu poses a he s and densi ies con en ionally used in sou he n Eu ope? Chap e IV
The e ec s o o es s as ega ds clima e change mi iga ion may be de i ed om p oduc yield,
bioene gy subs i u ion and C s ocks in biomass and soils (Canadell & Raupach, 2008). P oduc
yield is usually exp essed in e ms o ha es ed o p oduced olume, whe eas bioene gy
subs i u ion is usually exp essed in e ms o ene gy, o onnes oil equi alen (TOE). This depends
on he ans o ma ion p ocedu e o he biomass in ques ion. When ene gy is ans o med by
combus ion i is he high hea ing alue (HHV) o each biomass compa men ha de e mines he
ans o ma ion pe o mance. When he biomass is ans o med o second gene a ion bio uels (i.e.
bioe hanol), i is he cellulose con en ha de e mines he ans o ma ion a e o his ype o ene gy.
The TOE in each case depends on he sou ce o ene gy subs i u ed, while he same amoun o
ene gy can be ob ained o combus ion o se e al ypes o combus ible; as a con en ion, his mus
be exp essed in e ms o he ene gy eleased by he combus ion o one Mg o oil (4·1010 J), which
is equi alen o a 1.4 Mg o coal, 4.5 Mg o ligni e and 10·103 m3 o na u al gas.
The adi ional way o es ima ing his ype o bioene gy p oduc ion is om olume o biomass
(Fig. 1.2). This implies a second es ima ion phase in which he ene ge ic yield alue is es ima ed
om olume o biomass. A di ec ela ion o each one o hese o ms o ene gy o ca bon by
speci ic models may a oid conca ena ing e o s. Mo eo e , his would allow mo e accu a e
compa ison o se e al managemen al e na i es o he use o pa icula species o ene gy
pu poses.

CHAPTER I
20
BEFs
ENERGY
STAND-
TREE
VARIABLES
VE
ENERGY EQUATIONS
CARBON
CARBON EQUATIONS
USABLE
CELLULOSE
CC
LHV
SPECIFIC COMPSUMPTION
USABLE CELLULOSE EQUATIONS
BIOMASS EQUATIONS
BIOMASS
VOLUME
BEFs
ENERGY
STAND-
TREE
VARIABLES
VE
ENERGY EQUATIONS
CARBON
CARBON EQUATIONS
USABLE
CELLULOSE
CC
LHV
SPECIFIC COMPSUMPTION
USABLE CELLULOSE EQUATIONS
BIOMASS EQUATIONS
BIOMASS
VOLUME
Figu e 1.2. P ocess o biomass, ca bon, ene gy and usable cellulose es ima ion om s and o ee a iables. VE:
olume equa ions; BEFs: biomass expansion ac o s; CC ca bon concen a ion in biomass; LHV low hea ing alue.
Mos s udies ha compa e species o managemen al e na i es o sho o a ion woody c ops
(SRWC) a e based on a small numbe o plo s (Mi chell e al., 1999; Sims e al., 1999b; Dickmann,
2006), some imes a ew ees, and usually es ablished a e y high densi ies. As hinning is no
applied in SRWC managemen , s a ic g ow h models may be sui able o yield and bioene gy
p oduc ion modeliza ion, al hough such s udies a e s ill sca ce and ocus on species used o
SRWC in no he n Eu ope. Because o he la ge ins alla ion cos s o hese high densi y c ops, he
equi emen s o some dimensional cons ain s o ha es ing and p oduc ion o second gene a ion
combus ibles, and he low implemen a ion o his ype o c op in he no h o Spain, he p o i abili y
o he cu en managemen schemes o bioene gy p oduc ion is being in es iga ed. This is
impo an because i ep esen s he ac ual po en ial o p oduce biomass wi hou subs an ial
changes o exis ing managemen schemes.
The ques ions add essed in Chap e IV a e:
 How well a e s anda d low densi y plan a ions o Eucalyp us adap ed o bioene gy
pu poses and ca bon seques a ion in no he n Spain?
 How do ha es ing limi a ions as ega ds ee size a ec s and managemen in sho
o a ion woody c ops o Eucalyp us?
 How wide is he managemen window as ega ds sel hinning o each ini ial s ocking
densi y?
1.4.4. How does soil o ganic ma e na u e change du ing a o es a ion o o me
pas u e land? Chap e V
Al hough he i s s ep in desc ibing SOC dynamics a e land use change is o examine
changes in o al SOC, he e a e la ge di e ences among SOM compounds ega ding s abili y,
GENERAL INTRODUCTION AND OBJECTIVES
21
which mus he e o e be s udied in g ea e de ail. Al hough he e a e some s udies abou he e ec
o clima e change on he chemical s abili y o soil o ganic ma e compounds (Bellamy e al., 2005;
Ki schbaum, 2006), he e is an impo an gap in he knowledge abou he chemical na u e o he
SOC ollowing land use change. While in o ma ion abou o al SOC may sugges ha all C
eleased a e land use change occu in he mos labile ac ions, i is known ha deg ada ion o
ecalci an o ganic ma e eadily akes place in uppe ho izons in which some s abiliza ion
p ocesses a e less ac i e han in deepe ho izons ( on Lü zow e al., 2006). Mo eo e , mo e
de ailed wo k is necessa y o examine changes in his ype o p ocess, since he adi ional
classi ica ion o SOC in o labile and ecalci an is no su icien o desc ibing he SOC s abili y and
dynamics.
T adi ional echniques o examining changes in chemical SOC s abili y include 13C CP-MAS
NMR, Fou ie ans o m in a ed spec oscopy and py olysis/GC-MS. Al hough hese me hods a e
highly ep oducible and accu a e, hey a e also expensi e and ime consuming. Howe e , some
s udies on SOM dynamics, especially hose ocused on modelling equi es analysis o a la ge
numbe o samples, while a he same ime o e ing a high deg ee o ep oducibili y and accu acy.
In his sense, calo ime y and he mal analysis a e apid, inexpensi e echniques ha p o ide
in o ma ion abou he s abili y o SOC and ha e al eady been es ed in s eady s a e sys ems.
Ne e heless, accu a e me hods o desc ibing dynamic p ocesses a e being in es iga ed.
The ques ions add essed in Chap e V a e:
 Wha ac ions o SOC a e a ec ed by he losses when la ge losses o SOC occu in he
soil?
 How sui able a e calo ime y and he mal analysis o de ec ing SOC s abili y changes in
o es soils?
1.4.5. How do managemen p ac ices a ec he mi iga ion e ec o as g owing
plan a ions es ablished on o me pas u e land? Chap e VI
P edic ion h ough empi ical models is es ic ed o unchanged condi ions a he han o
adjus ed condi ions (IPPC, 2006). This also implies ha managemen p ac ices a e conside ed o
be he same as hose obse ed in he popula ion modelled. The equilib ium be ween managemen
in ensi y, C s ock and mi iga ion e ec is di icul o assess. Al hough excessi e ha es ing
schedules can lead o se e e damage o o es ecosys ems, unde -ha es ing can lead o unde
use o he s and po en ial, and main enance o he o es a mo e uns able s ages o de elopmen ,
as ega ds e.g. i es, s o m e en s and diseases. This mus be conside ed o maximizing he
po en ial o o es s as ega ds clima e change mi iga ion. The e ec o se e al managemen
p ac ices on changes in o es C accumula ion mus be assessed wi h models ha a e sensi i e o
his ype o change.
In his sense, he CO2Fix model (Nabuu s e al., 2002; Mase a e al., 2003; Schelhaas e al.,
2004) enables es ima ion o he changes in C s ocks and luxes by use o he ull ca bon
CHAPTER I
22
accoun ing app oach. This model is di ided in o six modules: biomass, soil, p oduc s, bioene gy,
inancial and ca bon accoun ing. Changes in C in all modules a e d i en by cu en annual
inc emen s in he species conside ed, and also by he clima ic da a and he ini ial condi ions
ega ding C s ock. The use ulness o he model has al eady been demons a ed o e en and
une en-aged o es s ands wo ldwide (Schelhaas e al., 2004; G oen e al., 2006), enabling
compa ison be ween di e en managemen p ac ices and also ini ial condi ions.
Since he e a e no ei he pu ely eco-physiological o empi ical models (Landsbe g & Sands,
2011), es ima ions o some modules o he model used a e ob ained om empi ical da a. Al hough
p e ious s udies o he sensi i i y o he chosen model in ega d o he inpu da a indica es ha
yield ables a e one o he mos impo an pa ame e s (Nabuu s e al., 2008), di e en models a e
some imes a ailable and di ec measu emen s a e no always a ailable o alida ion. Th ee
di e en models we e he e o e used o p oduce yield ables and we e alida ed wi h measu ed
da a. This same p ocess was ca ied ou wi h he soil module, since he e was no su icien
in o ma ion abou i s use ulness o sou he n Eu opean condi ions. Mo eo e , he e is no enough
in o ma ion abou he mi iga ion e ec o o es p oduc s a ailable on he no he n Spain ma ke .
The ques ions add essed in Chap e VI a e:
 How impo an a e accu a e yield ables o desc ibing C accumula ion on biomass by
using he CO2Fix model?
 How well does he soil module o he CO2Fix model (Yasso model) enable es ima ion o
he changes in C in o es soils in no he n Spain, and how sensi i e is he module o
u no e a e pa ame e s?
 How do si e condi ions and managemen al e na i es a ec he C accumula ion e ec in
as g owing plan a ions es ablished on o me pas u e land?
 Wha is he con ibu ion o o es p oduc s and bioene gy subs i u ion o he mi iga ing
e ec o he o es plan a ions in no he n Spain?
1.5. Objec i es
The o e all objec i e o his hesis was o de elop me hods and ools o es ima ing ca bon
s ocks in biomass and soil in Pinus adia a (D.Don), Eucalyp us globulus (Labill) and Eucalyp us
ni ens (Dean & Maiden) Maiden plan a ions o e o me ag icul u al land in no h-wes e n Spain.
The speci ic objec i es we e:
 To e alua e ca bon accumula ion in biomass, li e and soil on o me ag icul u al land
a o es ed wi h di e en species (Chap e II).
GENERAL INTRODUCTION AND OBJECTIVES
23
 To de elop biomass equa ions a ee le el o E. ni ens plan a ions, and o e alua e he
e ec s on ee d y mass es ima ion o he sampling in ensi y, sampling me hodology and
independen a iables conside ed (Chap e III).
 To e alua e he ene ge ic and ca bon seques a ion abili y o E. globulus and E. ni ens
plan a ions in sho o a ion woody c ops (Chap e IV).
 To e alua e he s abili y o he soil o ganic ma e a e land use change om pas u e o
o es plan a ion wi h as g owing ee species (Chap e V).
 To e alua e he mi iga ion e ec o se e al managemen egimes o he ee species
s udied, conside ing he whole p oduc cycle and he s ock e ec on soil and biomass
(Chap e VI).
1.6. Re e ences
Ál a ez, P. 2004. Vi e os o es ales y uso de plan a en epoblación en Galicia. Tesis Doc o al.
Lugo, Spain, Uni e si y o San iago de Comos ela.
An ónio, N.; Tomé, M.; Tomé, J.; Soa es, P. & Fon es, L. 2007. E ec o ee, s and, and si e
a iables on he allome y o Eucalyp us globulus ee biomass. Canadian Jou nal o Fo es
Resea ch. 37 (5): 895-906.
Baldocchi, D. 2008. 'B ea hing'o he e es ial biosphe e: lessons lea ned om a global ne wo k o
ca bon dioxide lux measu emen sys ems. Aus alian Jou nal o Bo any. 56 (1): 1-26.
Baldocchi, D.; Falge, E.; Gu, L.; Olson, R.; Hollinge , D.; Running, S.; An honi, P.; Be nho e , C.;
Da is, K. & E ans, R. 2001. FLUXNET: A new ool o s udy he empo al and spa ial a iabili y
o ecosys em-scale ca bon dioxide, wa e apo , and ene gy lux densi ies. Bulle in o he
Ame ican Me eo ological Socie y. 82 (11): 2415-2434.
Ba eson, L.; Vellico, M.; Beaubien, S.E.; Pea ce, J.M.; Annunzia ellis, A.; Cio oli, G.; Co en, F.;
Lomba di, S. & Ma sh, S. 2008. The applica ion o emo e-sensing echniques o moni o
CO2-s o age si es o su ace leakage: me hod de elopmen and es ing a La e a (I aly)
whe e na u ally p oduced CO2 is leaking o he a mosphe e. In e na ional Jou nal o
G eenhouse Gas Con ol. 2 (3): 388-400.
Ba is i, A.; S as ny, M.; Ne he e , S.; Robine , C.; Schop , A.; Roques, A. & La sson, S. 2005.
Expansion o geog aphic ange in he pine p ocessiona y mo h caused by inc eased win e
empe a u es. Ecological Applica ions. 15 (6): 2084-2096.
Bellamy, P.H.; Lo eland, P.J.; B adley, R.I.; La k, R.M. & Ki k, G.J.D. 2005. Ca bon losses om all
soils ac oss England and Wales 1978-2003. Na u e. 437 (7056): 245-248.
Blennow, K. & Olo sson, E. 2008. The p obabili y o wind damage in o es y unde a changed wind
clima e. Clima ic Change. 87 (3): 347-360.
Boland, D.J.; B ooke , M.I.H. & Tu nbull, J.W. 1980. Eucalyp us Seed Canbe a, Aus alia. 191 pp.
B a o, F. 2007. El papel de los bosques españoles en la mi igación del cambio climá ico
Fundación Gas Na u al, Ba celona, Spain. 315 pp.
B iggs, R.D.; Cunia, T.; Whi e, E.H. & Yawney, H.W. 1987. Es ima ing sample ee biomass by
subsampling: some empi ical esul s. Es ima ing T ee Biomass Reg essions and Thei
E o .P oceedings o he Wo kshop on T ee Biomass Reg ession Func ions and hei
Con ibu ion o he E o o Fo es In en o y Es ima es.Compiled by EH Wha on and
T.Cunia.USDA Fo .Se .Gen.Tech.Rep.NE-117. : 119-127.
CHAPTER I
24
B own, S.; Lim, B. & Schlamadinge , B. 1999. E alua ing app oaches o es ima ing ne emissions
o ca bon dioxide om o es ha es ng and wood p oduc s. Mee ing epo , Daka , 5-7 May
1998 Edn., IPCC/OECD/IDEA P og amme on Na ional G eenhouse Gas In en o ies, Pa is.
Campioli, M.; Hä könen, S.; Lomba di, F.; Lucas-Bo ja, M.E.M., D.; Pé ez-C uzado, C.; Rä y, T. &
Si ko a, Z. 2009. Role o Fo es Resea ch in Figh ing Clima e Change-Fo es Resea ch Wo k
G oup Repo . En: Figh ing Clima e Change: Adap ing Fo es Policy and Fo es Managemen
in Eu ope. Eds. T. Ka jalainen, M. Lindne , A. Niskanen & M. Lie , Joensuu Fo es y
Ne wo king Week 2009 Edn., Finnish Fo es Resea ch Ins i u e (METLA), Joensuu, Finland.
Canadell, J.G. & Raupach, M.R. 2008. Managing o es s o clima e change mi iga ion. Science.
320 (5882): 1456-1457.
Ca ey, E.V.; Sala, A.; Keane, R. & Callaway, R.M. 2001. A e old o es s unde es ima ed as global
ca bon sinks? Global Change Biology. 7 (4): 339-344.
Ca le, J.B. & Holmg en, L.P.B. 2009. Wood om Plan ed Fo es s: Global Ou look o 2030. En:
Plan ed Fo es s. Uses, Impac s & Sus ainabili y. Ed. J. E ans, Food and Ag icul u e
O ganiza ion o he Uni ed Na ions (FAO) and CAB In e na ional, Rome, I aly. 47-60 pp.
Ca alho, J.P. & Pa esol, B.R. 2003. Addi i i y in ee biomass componen s o Py enean oak
(Que cus py enaica Willd.). Fo es Ecology and Managemen . 179 (1-3): 269-276.
Cla k, A. 1982. P edic ing biomass p oduc ion in he Sou h. En: P edic ing G ow h and Yield in he
Mid-Sou h 119-139 pp.
Conen, F.; Ze a, A.; A ouays, D.; Joli e , C.; Ja is, P.G.; G ace, J. & Mencuccini, M. 2004. The
ca bon balance o o es soils: de ec abili y o changes in soil ca bon s ocks in empe a e and
bo eal o es s. En: The Ca bon Balance o Fo es Biomes. Eds. H. G i i hs & P.G. Ja is,
Ga land Science/BIOS Scien i ic Publishe s, Sou hamp on, UK. 233-247 pp.
Co e ill, P. & Mac ae, S. 1997. Imp o ing eucalyp us pulp and pape quali y using gene ic
selec ion and good o ganiza ion. Tappi Jou nal. 80 (6): 82-89.
Del Lungo, A. 2009. Plan ed Fo es A eas by Coun y. En: Plan ed Fo es s. Uses, Impac s &
Sus ainabili y. Ed. J. E ans, Food and Ag icul u e O ganiza ion o he Uni ed Na ions (FAO)
and CAB In e na ional, Rome, I aly. 155-180 pp.
Dias, A.C.; A oja, L. & Capela, I. in p ess. Ca bon s o age in ha es ed wood p oduc s:
implica ions o di e en me hodological p ocedu es and inpu da a—a case s udy o Po ugal.
Eu opean Jou nal o Fo es Resea ch. : 1-9.
Dickmann, D.I. 2006. Sil icul u e and biology o sho - o a ion woody c ops in empe a e egions:
Then and now. Biomass and Bioene gy. 30 (8-9): 696-705.
E ans, J.; Ca le, J.B.; Ball, J.B.; Del Lungo, A.; Neilson, D.A. & Holmg en, L.P.B. 2009. Plan ed
Fo es s. Uses, Impac s & Sus ainabili y Food and Ag icul u e O ganiza ion o he Uni ed
Na ions (FAO) and CAB In e na ional, Rome, I aly. 213 pp.
FAO 2005. Global Fo es Resou ces Assessmen 2005 Food and Ag iculu al O ganiza ion o he
Uni ed Na ions (FAO), Rome, I aly.
Foley, J.A.; DeF ies, R.; Asne , G.P.; Ba o d, C.; Bonan, G.; Ca pen e , S.R.; Chapin, F.S.; Coe,
M.T.; Daily, G.C. & Gibbs, H.K. 2005. Global consequences o land use. Science. 309 (5734):
570-574.
Ful on, L.; Howes, T. & Ha dy, J. 2004. Bio uels o anspo : an in e na ional pe spec i e OECD,
In e na ional Ene gy Agency, Pa is, F ance.
González-Río, F.; Cas ellanos, A.; Fe nández, O. & Gómez, C. 1997. Manual de sel icul u a del
Eucalip o Uni e sidad de San iago de Compos ela, Escuela Poli écnica Supe io de Lugo. 92
pp.
G ace, J. 2004. Unde s anding and managing he global ca bon cycle. Jou nal o Ecology. 92 (2):
189-202.

GENERAL INTRODUCTION AND OBJECTIVES
25
G acia, C.; Sánchez, A.; Pla, E.; Saba é, S.; Lexe , M.J. & Jäge , D. 2005. Adap i e o es
managemen s a egies. En: Managemen o Eu opean o es unde changing clima ic
condi ions. Eds. S. Kellomäki & S. Leinone, Resea ch No es Nº163 Edn., Facul y o Fo es y,
Uni e si y o Joensuu, Joensuu, Finland. 160-252 pp.
G oen, T.; Nabuu s, G. & Schelhaas, M. 2006. Ca bon accoun ing and cos es ima ion in o es y
p ojec s using CO2Fix V. 3. Clima ic Change, 74. 1 (3): 269-288.
Guai a, M. & Ei as, A. 2007. Es udio compa a i o en e la made a de pino y de eucalip o pa a
di e sas ipologías es uc u ales. Bole ín del CIDEU. 4: 71-76.
Ham ick, J.L. 2004. Response o o es ees o global en i onmen al changes. Fo es Ecology and
Managemen . 197 (1-3): 323-335.
Hansen, J.E. & Lacis, A.A. 1990. Sun and dus e sus g eenhouse gases: An assessmen o hei
ela i e oles in global clima e change. Na u e. 346 (6286): 713-719.
Ha mon, M.E.; Fe ell, W.K. & F anklin, J.F. 1990. E ec s on ca bon s o age o con e sion o old-
g ow h o es s o young o es s. Science. 247 (4943): 699.
Hough on, J.T.; Filho, L.M.; Lim, B.; T ean on, K.; Mama y, I.; Bonduki, Y.; G iggs, D. & Callende ,
B. 1997. Re ised 1996 IPPC guidelines o na ional g eenhouse gas in en o ies.
IPPC/OECD/IEA UK Me eo ological O ice, B acknell, UK.
Hough on, J.T.; Jenkins, G.J. & Eph aums, J.J. 1990. Clima e change: he IPCC scien i ic
assessmen Camb idge Uni e si y P ess, Camb idge, MA (Uni ed S a es). 310 pp.
Hough on, R.A. 2003. Why a e es ima es o he e es ial ca bon balance so di e en ? Global
Change Biology. 9 (4): 500-509.
House, J.I.; P en ice, I.C.; Ramanku y, N.; Hough on, R.A. & Heimann, M. 2003. Reconciling
appa en inconsis encies in es ima es o e es ial CO2 sou ces and sinks. Tellus B. 55 (2):
345-363.
INFOR 2004. Eucalyp us ni ens en Chile: P ime a monog a ía INFOR CORFO, Valdi ia, Chile. 142
pp.
IPPC 2007. Clima e change 2007: he phisical science basis, (suma y o Policymake s). URL:
h p://ipcc-wg1.uca .edu/wg1/docs/WG1AR4_SPM_Plena yApp o ed.pd
Consul ado:Diciemb e/15.
IPPC 2006. 2006 IPPC Guidelines o Na ional G eenhouse Gas In en o ies In e gube namen al
Pannel o Clima e Change, Japan.
IPPC 2003. Good p ac ice guidance o land use, land-use change and o es y. Na ional
G eenhause Gas In en o ies P og amme. In e gube namen al Pannel o Clima e Change,
Kanagawa, Japan. 295 pp.
IPPC 2001. Clima e change 2001: he scien i ic basis. En: Con ibu ion o Wo king G oup I o he
Thi d Assessmen Repo o he In e go e nmen al Panel on Clima e Change. Eds. J.T.
Hough on, Y. Ding, D.J. G iggs, e al, Camb idge Uni e si y P ess, Camb idge, U.K. 881 pp.
Jandl, R.; Lindne , M.; Ves e dal, L.; Bauwens, B.; Ba i z, R.; Hagedo n, F.; Johnson, D.W.;
Minkkinen, K. & By ne, K.A. 2007. How s ongly can o es managemen in luence soil ca bon
seques a ion? Geode ma. 137 (3-4): 253-268.
Jones, P.D.; Osbo n, T.J. & B i a, K.R. 2001. The e olu ion o clima e o e he las millennium.
Science. 292 (5517): 662.
Jones, P. & Mobe g, A. 2003. Hemisphe ic and la ge-scale su ace ai empe a u e a ia ions: An
ex ensi e e ision and an upda e o 2001. Jou nal o Clima e. 16 (2): 206-223.
Kaipainen, T.; Liski, J.; Pussinen, A. & Ka jalainen, T. 2004. Managing ca bon sinks by changing
o a ion leng h in Eu opean o es s. En i onmen al Science & Policy. 7 (3): 205-219.
Keenan, T.; Saba e, S. & G acia, C. 2008. Fo es eco-physiological models and ca bon
seques a ion. Managing Fo es Ecosys ems: The Challenge o Clima e change. 17 (3): 83-
102.
CHAPTER I
26
Ki schbaum, M.U.F. 2006. The empe a u e dependence o o ganic-ma e decomposi ion--s ill a
opic o deba e. Soil Biology and Biochemis y. 38 (9): 2510-2518.
Ki schbaum, M.U.F. 2003. To sink o bu n? A discussion o he po en ial con ibu ions o o es s o
g eenhouse gas balances h ough s o ing ca bon o p o iding bio uels. Biomass and
Bioene gy. 24 (4-5): 297-310.
Landsbe g, J.J. & Sands, P.J. 2011. Phisiological Ecology o Fo es P oduc ion. P inciples,
P ocess and Models. Volume 4 Edn., Else ie Academic P ess, Bu ling on, USA. 331 pp.
Lasan a, T. 1996. El p oceso de ma ginación de ie as en España. En: E osión y ecupe ación de
ie as en á eas ma ginales. Eds. T. Lasan a & J.M. Ga cía Ruiz, Sociedad Española de
Geomo ología, Log oño, Spain. 7-31 pp.
La e y, P.B. 1986. Plan a ion o es y wi h Pinus adia a: e iew pape s. Pape Nº 12 Edn., School
o Fo es y, Uni e si y o Can e bu y, New Zealand.
La o el, S.; Touza d, B.; Leb e on, J.D. & Clémen , B. 1998. Iden i ying unc ional g oups o
esponse o dis u bance in an abandoned pas u e. Ac a Oecologica. 19 (3): 227-240.
Lindne , M. & Ka jalainen, T. 2007. Ca bon in en o y me hods and ca bon mi iga ion po en ials o
o es s in Eu ope: a sho e iew o ecen p og ess. Eu opean Jou nal o Fo es Resea ch.
126 (2): 149-156.
Lindne , M.; Ma oschek, M.; Ne he e , S.; K eme , A.; Ba ba i, A.; Ga cia-Gonzalo, J.; Seidl, R.;
Delzon, S.; Co ona, P. & Kols öm, M. 2010. Clima e change impac s, adap i e capaci y, and
ulne abili y o Eu opean o es ecosys ems. Fo es Ecology and Managemen . 259 (4): 698-
709.
Liski, J.; Pe uchoud, D. & Ka jalainen, T. 2002. Inc easing ca bon s ocks in he o es soils o
wes e n Eu ope. Fo es Ecology and Managemen . 169 (1-2): 159-175.
Liski, J.; Pussinen, A.; Pingoud, K.; Mäkipää, R. & Ka jalainen, T. 2001. Which o a ion leng h is
a ou able o ca bon seques a ion? Canadian Jou nal o Fo es Resea ch. 31 (11): 2004-
2013.
Li le, K.M. & Ga dne , R.A.W. 2003. Coppicing abili y o 20 Eucalyp us species g own a wo high-
al i ude si es in Sou h A ica. Canadian Jou nal o Fo es Resea ch. 33 (2): 181-189.
Löwe, H.; Seu e , G. & Raes, F. 2000. Compa ison o me hods used wi hin Membe S a es o
es ima ing CO~ 2 emissions and sinks acco ding o UNFCCC and EU Moni o ing Mechanism:
o es and o he wooded land. Bio echnologie Ag onomie Socie e e En i onnemen . 4 (4):
315-319.
Luyssae , S.; Schulze, E.D.; Bö ne , A.; Knohl, A.; Hessenmölle , D.; Law, B.E.; Ciais, P. & G ace,
J. 2008. Old-g ow h o es s as global ca bon sinks. Na u e. 455 (7210): 213-215.
Malhi, Y.; Mei , P. & B own, S. 2002. Fo es s, ca bon and global clima e. Philosophical
T ansac ions o he Royal Socie y o London. Se ies A: Ma hema ical, Physical and
Enginee ing Sciences. 360 (1797): 1567-1591.
Malhi, Y.; Robe s, J.T.; Be s, R.A.; Killeen, T.J.; Li, W. & Nob e, C.A. 2008. Clima e change,
de o es a ion, and he a e o he Amazon. Science. 319 (5860): 169-172.
Mansilla Vázquez, J.P. 1992. P esencia sob e Eucalyp us globulus Labill de Gonep e us
scu ella us Gyll (Col. Cu culionidae) en Galicia. Bole ín de Sanidad Vege al: Plagas. 18 (3):
547-554.
MAPA 2006. Fo es ación de Tie as Ag ícolas: Análisis de su e olución y con ibución a la ijación
de ca bono y al uso acional de la ie a Spanish Minis y o Ag icul u e, Fishe ies and Food,
Mad id (Spain).
Mase a, O.R.; Ga za-Caliga is, J.F.; Kanninen, M.; Ka jalainen, T.; Liski, J.; Nabuu s, G.J.;
Pussinen, A.; De Jong, B.H.J. & Moh en, G.M.J. 2003. Modeling ca bon seques a ion in
a o es a ion, ag o o es y and o es managemen p ojec s: he CO2FIX V. 2 app oach.
Ecological Modelling. 164 (2-3): 177-199.
GENERAL INTRODUCTION AND OBJECTIVES
27
McMahon, S.M.; Pa ke , G.G. & Mille , D.R. 2010. E idence o a ecen inc ease in o es g ow h.
P oceedings o he Na ional Academy o Sciences. 107 (8): 3611-3615.
Meehl, G.A.; S ocke , T.F.; Collins, W.D.; F iedlings ein, P.; Gaye, A.T.; G ego y, J.M.; Ki oh, A.;
Knu i, R.; Mu phy, J.M. & Noda, A. 2007. Global clima e p ojec ions. En: Clima e Change
2007: The Physical Science Basis. Con ibu ion o Wo king G oup I o he Fou h Assessmen
Repo o he In e go e nmen al Panel on Clima e Change. Eds. S. Solomon, D. Qin, M.
Manning, e al, IPPC, Camb idge, U.K. 747-845 pp.
Melillo, J.M.; Reilly, J.M.; Kickligh e , D.W.; Gu gel, A.C.; C onin, T.W.; Pal se , S.; Felze , B.S.;
Wang, X.; Sokolo , A.P. & Schlosse , C.A. 2009. Indi ec emissions om bio uels: How
impo an ? Science. 326 (5958): 1397-1399.
Mi chell, C.P.; S e ens, E.A. & Wa e s, M.P. 1999. Sho - o a ion o es y- ope a ions, p oduc i i y
and cos s based on expe ience gained in he UK. Fo es Ecology and Managemen . 121: 123-
136.
Nabuu s, G.J.; Ga za-Caliga is, J.F.; Kanninen, M.; Ka jalainen, T.; Lap e elainen, T.; Liski, J.;
Mase a, O.; Moh en, G.M.J.; Olgin, M.; Pussinen, A. & Schelhaas, M. 2002. CO2FIX V2.0.
Manual o a model o quan i ying ca bon seques a ion in o es ecosys ems and wood
p oduc s. Repo 445 Edn., Al e a, Wageningen, The Ne he lands. 44 pp.
Nabuu s, G.J.; an Pu en, B.; Knippe s, T.S. & Moh en, G.M.J. 2008. Compa ison o unce ain ies
in ca bon seques a ion es ima es o a opical and a empe a e o es . Fo es Ecology and
Managemen . 256 (3): 237-245.
Ney, R.A.; Schnoo , J.L. & Mancuso, M.A. 2002. A me hodology o es ima e ca bon s o age and
lux in o es land using exis ing o es and soils da abases. En i onmen al Moni o ing and
Assessmen . 78 (3): 291-307.
Nu o, L. & Touza Vázquez, M.C. 2004. P oducción de Made a de Sie a de al a Calidad con
Eucalyp us globulus. CIS-Made a. 12: 6-18.
Oli e , G.R.; Bee s, P.N.; Ga e , L.G.; Pea ce, S.H.; Kimbe ly, M.O.; Fo d-Robe son, J.B. &
Robe son, K.A. 2004. Va ia ion in soil ca bon in pine plan a ions and implica ions o
moni o ing soil ca bon s ocks in ela ion o land-use change and o es si e managemen in
New Zealand. Fo es Ecology and Managemen . 203 (1-3): 283-295.
O e o, L.; Aguín, O.; Sainz, M. & Mansilla, J.P. 2007. El géne o Mycosphae ella en plan aciones
de Eucalyp us en Galicia. Bole ín de Sanidad Vege al: Plagas. 33 (4): 503-516.
Pa dos, J.A. 2010. Los ecosis emas o es ales y el secues o de ca bono an e el calen amien o
global. Monog a ías INIA: Se ie Fo es al Edn., Ins i u o Nacional de In es igación y
Tecnología Ag a ia y Alimen a ia, Minis e io de Ciencia e Inno ación, Mad id, Spain. 253 pp.
Paz, J. 1999. Análisis compa a i o de las p opiedades mic oscópicas y mac oscópicas de la
made a de Eucalyp us ni ens y Eucalyp us globulus. En: XII Sil o ecna, Realidad y po encial
del Eucalyp us en Chile (Concepción, Chile).
Pemán Ga cía, J.; Ru i e a B ujan, J. & Blanco O iz, R. 2009. In luencia de la disponibilidad de
supe icie en la ac i idad epoblado a desa ollada po la adminis ación en e 1940 y 1973.
En: Ac as del Cong eso de His o ia Fo es al, III Reunión sob e His o ia Fo es al. Eds. F.J.
Sil a-Pando, E. Ga cía Gómez, J. Pe ei a Sieso & J. Ca obles San os, Cuade onos de la
Sociedad Española de Ciencias Fo es ales (Nº 30) Edn., Sociedad Española de Ciencias
Fo es ales, Toledo, Spain. 325-330 pp.
Pé ez, S.; Renedo, C.J.; O iz, A. & Manana, M. 2008. Ene gy po en ial o was e om 10 o es
species in he No h o Spain (Can ab ia). Bio esou ce Technology. 99 (14): 6339-6345.
P egi ze , K.S. & Euski chen, E.S. 2004. Ca bon cycling and s o age in wo ld o es s: biome
pa e ns ela ed o o es age. Global Change Biology. 10 (12): 2052-2077.
Righela o, R. & Sp acklen, D.V. 2007. Ca bon mi iga ion by bio uels o by sa ing and es o ing
o es s. Science. 317 (5840): 902-902.
CHAPTER I
28
Rod íguez-Mu illo, J.C. 1999. El ciclo mundial del ca bono. Mé odo de cálculo po los cambios de
uso de la ie a. Balance de ca bono en los bosques españoles. En: El calen amien o global
en España. Ed. F. He nández-Ál a ez, CSIC, Mad id, Spain. 97-139 pp.
Ruiz de la To e, J.; Ceballos y Fe nández de Có doba, L.; Ceballos Jiménez, M. & Ruiz del
Cas illo y de Na ascúes, J. 1979. Á boles y a bus os de la España peninsula Escuela
Técnica Supe io de Ingenie os de Mon es, Mad id (Spain). 512 pp.
Sa oo, T. & Madgwick, H.A.I. (eds) 1982. Fo es Biomass, JSTOR, The Ne he lands.
Saugie , B.; Roy, J. & Mooney, H.A. 2001. Es ima ions o global e es ial p oduc i i y: con e ging
owa d a single numbe ? En: Te es ial global p oduc i i y. Eds. J. Roy, B. Saugie & H.A.
Mooney, Academic P ess, San Diego, CA. 543-557 pp.
Schelhaas, M.J.; an Esch, P.W.; G oen, T.A.; de Jong, B.H.J.; Kanninen, M.; Liski, J.; Mase a, O.;
Moh en, G.M.J.; Nabuu s, G.J.; Palosuo, T.; Ped oni, L.; Vallejo, A. & Vilén, T. 2004. CO2FIX
V 3.1 A modelling amewo k o quan i ying ca bon seques a ion in o es ecosys ems
Al e a, Wageningen, (The Ne he lands). 122 pp.
Sea chinge , T.; Heimlich, R.; Hough on, R.A.; Dong, F.; Elobeid, A.; Fabiosa, J.; Tokgoz, S.;
Hayes, D. & Yu, T.H. 2008. Use o US c oplands o bio uels inc eases g eenhouse gases
h ough emissions om land-use change. Science. 319 (5867): 1238-1240.
Shukla, J.; Nob e, C. & Selle s, P. 1990. Amazon de o es a ion and clima e change. Science. 247
(4948): 1322-1325.
Sims, R.E.H.; Maia a, T.G. & Bullock, B.T. 2001. Sho o a ion coppice ee species selec ion o
woody biomass p oduc ion in New Zealand. Biomass and Bioene gy. 20 (5): 329-335.
Sims, R.E.H.; Senelwa, K.; Maia a, T. & Bullock, B.T. 1999a. Eucalyp us species o biomass
ene gy in New Zealand—I: G ow h sc eening ials a i s ha es . Biomass and Bioene gy.
16 (3): 199-205.
Sims, R.E.H.; Senelwa, K.; Maia a, T. & Bullock, B.T. 1999b. Eucalyp us species o biomass
ene gy in New Zealand—Pa II: Coppice pe o mance. Biomass and Bioene gy. 17 (4): 333-
343.
Smi h, J.E.; Hea h, L.S. & Woodbu y, P.B. 2004. How o es ima e o es ca bon o la ge a eas
om in en o y da a. Jou nal o Fo es y. 102 (5): 25-31.
Solomon, S.; Pla ne , G.K.; Knu i, R. & F iedlings ein, P. 2009. I e e sible clima e change due o
ca bon dioxide emissions. P oceedings o he Na ional Academy o Sciences. 106 (6): 1704-
1709.
S åhl, G.; Bos öm, B.; Lindk is , H.; Lind o h, A.; Nilsson, J. & Olsson, M. 2004. Me hodological
op ions o quan i ying changes in ca bon pools in Swedish o es s. No. 214 Edn., Swedish
Uni e si y o Ag icul u al Sciences, Uppsala, Swedish. 46 pp.
Thomas, C.D.; Came on, A.; G een, R.E.; Bakkenes, M.; Beaumon , L.J.; Collingham, Y.C.;
E asmus, B.F.N.; De Siquei a, M.F.; G ainge , A. & Hannah, L. 2004. Ex inc ion isk om
clima e change. Na u e. 427 (6970): 145-148.
Thuille , W. 2003. BIOMOD-op imizing p edic ions o species dis ibu ions and p ojec ing po en ial
u u e shi s unde global change. Global Change Biology. 9 (10): 1353-1362.
Thuille , W.; La o el, S.; A aújo, M.B.; Sykes, M.T. & P en ice, I.C. 2005. Clima e change h ea s o
plan di e si y in Eu ope. P oceedings o he Na ional Academy o Sciences o he Uni ed
S a es o Ame ica. 102 (23): 8245.
Tilman, D.; Hill, J. & Lehman, C. 2006. Ca bon-nega i e bio uels om low-inpu high-di e si y
g assland biomass. Science. 314 (5805): 1598-1600.
T enbe h, K.E. & Josey, S.A. 2007. Obse a ions: su ace and a mosphe ic clima e change. En:
Clima e Change 2007: The Physical Science Basis. Con ibu ion o Wo king G oup I o he
Fou h Assessmen Repo o he In e go e nmen al Panel on Clima e Change. Eds. S.
INFLUENCE OF TREE SPECIES ON C SEQUESTRATION IN AFFORESTED PASTURES IN A HUMID TEMPERATE REGION
35
end o he o a ion. The a o es a ion may he e o e esul in high empo al C losses ia soil
espi a ion in compa ison wi h he C inpu s by li e . Some au ho s ha e sugges ed ha his is a
empo a y e ec , in which only he labile C pool is exhaus ed (Ce li e al., 2008; Huang e al.,
2011). Howe e , ecen e idence shows ha deg ada ion o ecalci an SOM can also occu in he
uppe mos soil laye s ( on Lü zow e al., 2006, Chap e V). I is no clea whe he hese ini ial
losses a e compensa ed in as g owing, in ensi ely managed species.
The C balance a e a o es a ion is g ea ly a ec ed by he ee species, as a esul o
di e ences in g ow h a es o he ees. In addi ion, li e p oduc ion and li e quali y, which a e
g ea ly in luenced by ee species, ha e a s ong in luence on he SOC dynamics (Be g, 2000;
Ves e dal e al., 2008). Howe e , since mos o he cu en knowledge is based on s udies o
a o es a ion wi h coni e ous species (Be h ong e al., 2009), he in luence o he ee species on
SOC dynamics has no ye been accu a ely e alua ed.
In s udies ha ha e a emp ed o e alua e he e ec o ee species on a o es ed land, he
di e ences in SOC dynamics a e a ibu ed o he in luence o he di e en u no e a es o he
li e (Ves e dal e al., 2008), he co e and ype o g ound ege a ion (Lemma e al., 2006), o bo h
(Paul e al., 2002; Huang e al., 2011; Kasel e al., 2011). The in luence o N- ixing ee species
has been also be ecognized (Nilsson & Schop hause , 1995; Kasel e al., 2011), as a highe yield
in poo soils leads o highe o ganic ma e inpu s o he soil, and also imp o es li e quali y and
he speed o decomposi ion o OM (Con eh e al., 1997). Recen s udies ha e shown ha hese
di e en sou ces o li e inpu s can e en lead o changes in he SOM composi ion (Huang e al.,
2011; Chap e V).
The capaci y o he soil o ac as a C sink is also in luenced by how apidly he li e con e s C
in o humus (Sil e e al., 2004; e.g. Kane a & Smolande , 2007; P esco , 2010). The
decomposabili y o he li e no only depends on i s chemical composi ion, bu also on
mic oclima ic condi ions de e mined by he di e en canopy de elopmen and s and s uc u e.
Mo eo e , he same mic oclima ic condi ions ha e a di ec in luence on he co e and ype o
g ound ege a ion, which in u n al e s he amoun s, composi ion and ype o li e (Os e ag e al.,
2008; Be g e al., 2009). This is pa icula ly impo an because oo s inco po a e mo e C in o he
soil han li e laye ma e ial (Jones e al., 2009). Thus, g ound ege a ion domina ed by g ass
species inco po a es C apidly in o soil o ganic ma e because he oo sys em de elops quickly
(And ade e al., 2008; Laungani & Knops, 2009).
The sil icul u al pa ame e s mos closely ela ed o SOC dynamics a e: ee species, si e
p epa a ion echniques, ini ial s ocking, o a ion leng h and o he pa ame e s mo e speci ic o each
ype o ee species managemen (p uning, clea cu ing, hinning, applica ion o e ilize , e c.) and
au oecology. These aspec s ha e been discussed by Jandl e al. (2007) and, in he case o he
species conside ed he e, by Balboa-Mu ias e al. (2006). In addi ion o managemen p ac ices, a
comp ehensi e ep esen a ion o he en i e o es y sec o sys em should be conside ed, aking
in o accoun he C pools and ossil uel subs i u ion, al hough he la e pool has no been
conside ed in he in e na ional ag eemen s on educ ion o emissions (UNFCCC, 2002). All o hese

CHAPTER II
36
ac o s a e pa icula ly impo an in as g owing ee species, in which in ensi e managemen in
sho o a ions, as well as ha es ing o logging esidues may p e en accumula ion o SOC in he
long e m.
Mos s udies conce ning he e ec o di e en species and ypes o managemen on C
seques a ion in a o es ed land ha e compa ed he C s ocks in se e al pools in pas u e land and
o es plan a ions in he s eady s a e, a he han conside ing he dynamic changes ha ake place.
In many cases, he shi s in key pa ame e s h oughou he o a ion, such as ee g ow h, s and
s uc u e, associa ed ege a ion and li e de elopmen a e no conside ed. Thus, he empo al
dynamics no only p o ide an unde s anding o he di e en mechanisms o C seques a ion a e
a o es a ion, bu a e also use ul o designing he mos app op ia e ype o managemen o
maximize he C sink capaci y.
Mos app oaches e alua ing he capaci y o soils as C sinks ocus on plo le el, and ew
s udies ha e been ex ended o landscape le els (Johns on e al., 1996; Tu ne & Lambe , 2000;
Conan e al., 2003). Such s udies show he high deg ee o a iabili y in he SOC dynamics
ollowing a o es a ion, e en unde a he homogeneous condi ions. This high a iabili y
emphasizes he isk o making e oneous conclusions abou SOC dynamics when he
expe imen al design does no ake his a iabili y in o accoun (Be g e al., 2009). A co ec
me hodology mus ensu e adequa e sampling eplica ion a plo le el, and p ope sample analysis
o ake in o accoun mos o he a iabili y o ex apola ion o he esul s o plo le el s udies o a
la ge scale (Goid s e al., 2009). Me hodological p ocedu es o quan i ying he changes in SOC
a e a o es a ion a e: (i) pai ed si es, (ii) ch onosequence s udies, (iii) mul iple e-sampling, and
(i ) p ocess and modelling s udies (Tu ne & Lambe , 2000).
Ch onosequence s udies use a se ies o plo s in plan a ions o di e en ages wi h supposedly
simila managemen egimes and en i onmen al condi ions, and ansla e spa ial di e ences
be ween soils in o empo al di e ences (Hugge , 1998). Al hough he ch onosequence app oach
canno eplace long- e m ield expe imen s, he e a e ce ain disad an ages wi h he la e , such as
he delay in ob aining esul s, wo kload and pa icula ends in ex e nal pa ame e s (i.e. clima e
and local condi ions), which may cause a sys ema ic bias in he obse a ions. The pai ed-plo s
app oach is an al e na i e me hod in which one o he pai ed plo s ep esen s he ini ial condi ions.
Because o he high spa ial a iabili y in SOC measu emen s (Johns on e al., 1996; Tu ne &
Lambe , 2000; Conan e al., 2003), he combined use o ch onosequences and he pai ed-plo s
app oach may p o ide a sui able way o de ec ing changes in soil pools, and o co ec ing local
endencies.
The objec i es o he p esen s udy we e: (i) o examine he in luence o ee species on he C
dynamics in he o es sys em ( ee biomass, li e and mine al soil) ollowing a o es a ion o
pas u e land, (ii) o explo e he ela ionships be ween ee biomass de elopmen on li e and SOC
dynamics in h ee o es plan a ions es ablished on o me pas u e land, and (iii) o e alua e he C
sink capaci y o he di e en ypes o plan a ions in ela ion o managemen . A speci ic
me hodology o sampling and da a managemen was designed o es ic mos o he a iabili y on
INFLUENCE OF TREE SPECIES ON C SEQUESTRATION IN AFFORESTED PASTURES IN A HUMID TEMPERATE REGION
37
a egional scale and he e o e o p o ide accu a e in o ma ion on C dynamics in he di e en ee
species plan ed. The design was applied o empe a e o es plan a ions o sou he n Eu ope, one
o he mos p oduc i e imbe p oduc ion sys ems in Eu ope, whe e impo an a o es a ion
p ocesses may play an impo an ole in mi iga ing CO2 and o he GHGs emissions. The da a
ob ained in his s udy will p o ide aluable in o ma ion abou he e ec s o such a o es a ion
p og ammes on C sink capaci y.
2.2. Ma e ials and me hods
2.2.1. Si e desc ip ion and expe imen al design
The s udy was ca ied ou in Galicia (NW Spain), in an a ea o 7000 km-2 ep esen a i e o he
A lan ic-clima e zone o no he n Spain. The 20 yea annual a e age ain all in he a ea is 1378
mm ( ange 884-2107 mm), and he empe a u e, 12.1ºC ( ange 10.3-14.8ºC). The we es mon h is
No embe , wi h an a e age ain all o 160 mm, and he d ies Augus , wi h 44 mm. The lowes
mean mon hly empe a u e 7.1ºC occu s in Janua y, and he highes 18.2ºC, in Augus . The soil
humidi y and empe a u e egimes a e Udic (mean pe iod wi h pa ial d ough , 1 mon h) and Mesic
(mean os - ee pe iod, 10 mon hs), espec i ely. The soils we e de eloped om g ani ic ocks,
schis and shale, and classi ied as Humic o Dis ic Cambisols and Alumi-humic Umb isols (IUSS
Wo king G oup WRB, 2006). The soil has a loam o sandy loam ex u e and is well d ained.
The a e age alues o selec ed cha ac e is ics o he a o es ed plan a ions s udied a e shown
in Table 2.1. In all plo s, he si e quali ies we e highe han in plan a ions es ablished on o me
o es soils, p obably because o he be e quali y o he soils (soil dep h, s oniness, highe wa e
supply) and p io e iliza ion. A ne wo k o 120 pai ed plo s, made up o o me pas u e plo s and
a o es ed plan a ions, was es ablished. The plo s we e dis ibu ed in h ee se s o 40 plo s plan ed
wi h he mos commonly used species in he a ea: Eucalyp us globulus Labill, Eucalyp us ni ens
(Deane & Maiden) Maiden and Pinus adia a D. Don. Each se was an independen
ch onosequence in which he ange o ages co e s he usual o a ion leng hs applied o hese
plan a ions, hus enabling conclusions o be eached as ega ds he e ec s o he single-s em
o a ion ollowing land use change: 1-23 yea s o E. globulus, 2-18 yea s o E. ni ens and 2-40
yea s o P. adia a ch onosequence espec i ely.
In all cases he p io use was as pas u e land, in which low in ensi e managemen was applied
o a leas 25 yea s (acco ding o landowne s), and some o which has ecen ly been a o es ed.
The plo s we e domina ed by a mix u e o Lolium mul i lo um, Lolium pe enne, T i olium p a ense,
T i oliun epens and Dac ylis glome a a, al hough as he ime since las pe u ba ion inc eased,
D. glome a a, Ag os is capilla is and Holcus lana us became mo e p edominan . The pas u es a e
no mally ha es ed o silage 1-2 imes a yea , and g azed once o wice a yea . They a e usually
CHAPTER II
38
enewed e e y 8-10 yea s by o o a ing o a dep h o 20 cm. In all cases, a o es a ion was ca ied
ou a e ipping a 50 cm dep h and plan ing along he ow, so ha soil dis u bance was
conside ed low. No e iliza ion o weed con ol was ca ied ou in he plan a ions. The pas u es
we e selec ed so ha ime since las illage was mo e han ou yea s. The minimum size o each
g assland and a o es ed plan a ion was 0.5 ha.
To ensu e ha all si es we e simila as ega ds soil ype and land use, selec ion o he s udy
si es was based on di ec obse a ion o he e ain in adjacen pas u es, and consul a ions wi h
landowne s. The plan a ion age was es ablished using an inc emen bo e o sum he ing numbe
o P. adia a and E. ni ens, which was clea ly isible and easy o assign o yea ly g ow h pe iods,
and conside ing he plan ing da e decla ed by he owne o he Fo es y Adminis a ion o E.
globulus.
Table 2.1. Main si e cha ac e is ics (a e age and s anda d de ia ion) o he s ands s udied.
Uni s E. globulus E. ni ens P. adia a
Numbe o s ands (n) 40 40 40
Age in e al (y ) 1-23 2-18 2-40
S and densi y (s ems ha-1) 1108 (309) 1011 (258) 1146 (410)
Bed ock (G ani ic ock /Schis -Sla es) (n) 8/32 5/35 25/15
Si e Index* (m) 23.3 (6.5) 15.3 (4.4) 24.8 (4.4)
Al i ude (m) 242 (173) 517 (63) 466 (115)
A e age annual Tempe a u e (ºC) 13.3 (1.0) 11.6 (0.5) 11.5 (0.8)
Accumula ed annual p ecipi a ion (mm) 1488 (377) 1434 (322) 1213 (219)
*Re e ence ages o si e index we e 10, 6 and 20 yea s o E. globulus, E. ni ens and P. adia a espec i ely.
Simila o es managemen egimes, in e ms o si e p epa a ion, sou ce o seedlings, and
p uning and ha es ing egimes, we e applied in all a o es ed s ands. S ands o E. globulus we e
loca ed in coas al a eas a al i udes below 300 m.a.s.l., whe eas E. ni ens and P. adia a s ands
we e loca ed in he inne a ea, gene ally be ween 300 and 500 m.a.s.l. As he selec ed s ands
we e simila in ega d o clima e, soils, ee species, p io land use and s and managemen , he
only heo e ically di e ence assumed among plo s was he age since a o es a ion.
2.2.2. C de e mina ion in abo e g ound ee biomass
Fo de e mining ca bon densi y (Mg C ha-1) in abo eg ound biomass, diame e s a b eas
heigh ( o he nea es cm) and o al heigh ( o he nea es dm) we e measu ed in all ees in
ci cula plo s o adius 10 m. D y weigh o abo eg ound biomass was es ima ed using he
equa ions p oposed by Me ino e al. (2005) o E. globulus, de eloped in Chap e III o E. ni ens,
and by Balboa-Mu ias e al. (2006) o P. adia a ch onosequences. The ca bon concen a ions in
INFLUENCE OF TREE SPECIES ON C SEQUESTRATION IN AFFORESTED PASTURES IN A HUMID TEMPERATE REGION
39
each biomass ac ion we e hose epo ed by he la e au ho s, excep o E. ni ens, o which he
alues epo ed in Chap e IV we e used.
2.2.3. Soil sampling and analysis
Fo sampling he soil (li e and mine al soil o 30 cm dep h), a 50 x 50 m plo was selec ed
wi hin each s and, a a dis ance o mo e han 30 m om he edge o he s and. Fi e samples pe
plo we e aken om be ween ee ows o minimize any dis u bance om he si e p epa a ion.
Fo sampling he li e laye , 0.3 x 0.3 m squa ed ames we e h own a andom wi hin each
plo , on 5 occasions. All abo eg ound soil li e was collec ed and d ied a 40ºC un il cons an
weigh . Ca bon con en s in he li e we e measu ed o E. ni ens (47.9%C), whe eas al eady
published da a we e used o E. globulus and P. adia a (Me ino e al., 2005).
Fo mine al soil, h ee soil laye s we e conside ed a dep hs o 0-5, 5-15 and 15-30 cm. The
i s wo co espond o he A ho izon, and he deepes laye A2, AB o BA. Sub-samples o he
mine al soil laye we e collec ed wi h a s eel co e , and we e combined o o m one bulk sample
pe plo . These samples we e o en-d ied a 40ºC, sie ed a 2 mm and he s oniness was
de e mined. In he ine soil ac ion, o al C and N we e analyzed wi h a LECO Elemen al analyze ,
whe eas soil pa icle analysis in he uppe 15 cm was pe o med by lase di ac ome y, wi h a
Mas e size 2000 di ac ome e .
A each sampling poin , i e densi y co e s we e collec ed in a 100 cm3 me al cylinde , which
was o en-d ied a 105ºC and weighed o de e mine he bulk densi y ollowing he me hodology o
Blake and Ha ge (1986). The C con en in each laye was de e mined by exp ession [2.1], whe e
CD is he ca bon densi y in each laye (Mg ha-1), CC is he ca bon concen a ion in each laye (as
a ac ion o uni y), Db is he bulk densi y (g cm-3), T is he hickness o each laye (cm) and S is
he s oniness (as a ac ion o uni y).


1001






STDbCCCD [2.1]
2.2.4. E alua ion o C seques a ion in he o es sys em
The amoun s o C in abo eg ound biomass and o ganic laye s was conside ed as ne gain
ela i e o pas u es, and he e o e only absolu e alues a e epo ed o plo ed agains ime since
a o es a ion. Fo modelling o abo eg ound biomass C changes wi h ime since a o es a ion, he
Richa ds (1959) model was used o desc ibe he ela ionship be ween abo eg ound biomass
ca bon (CW, Mg ha-1) and s and age ( , y ), shown in equa ion [2.2]. The model o each species
was i ed wi h he MODEL p ocedu e o he SAS/ETS® sys em (SAS Ins i u e Inc, 2004). The oo
o mean squa e e o s (RMSE) and adjus ed de e mina ion coe icien (Adjus . R2) we e calcula ed
o each model i .
CHAPTER II
40


2
1
1
0
b
b
WebC 
 [2.2]
Ca bon seques a ion in each mine al soil laye was e alua ed in absolu e e ms as he
di e ence be ween he o es subplo CDF and he pas u e subplo CDP (ca bon absolu e
di e ence CAD, Mg ha-1), and in ela i e e ms as he di e ence in pe cen age o ca bon densi y
(ca bon ela i e di e ence, CRD, % o ini ial ca bon densi y), wi h exp ession [2.3]. Bo h
pa ame e s we e ep esen ed in each plo agains ime since a o es a ion o e alua e he changes
in soil ca bon wi h ime since a o es a ion.
100


P
PF
CDCDCD
CRD [2.3]
To desc ibe changes in soil C o e ime, in p e ious s udies on changes in mine al soil ca bon
a e seconda y succession, an empi ical modelling app oach including he gamma unc ion was
used success ully (Co ing on, 1981; Zak e al., 1990). Howe e , in he p esen s udy he changes
a e expec ed o ollow a di e en pa e n, as we hypo hesized ha he C equilib ium le el is
di e en in pas u e han in a o es ed land, and he gamma is unc ion biologically inconsis en in
such cases. Al e na i e models include mo e pa ame e s han he gamma unc ion, making
con e gence o he pa ame ic model i di icul , al hough his will depend on he amoun o da a
a ailable. In his case, pa ame ic cu e i ing p ocedu es did no con e ge because o he la ge
numbe o pa ame e s needed o i a model ha adequa ely cap u es he appa en shape o he
da a. Thus, nonpa ame ic i ing was ca ied ou o desc ibe he gene al end in he changes in
li e and mine al soils. The LOESS p ocedu e in he SAS/STAT (SAS Ins i u e Inc, 2004), was
used o di ide esiduals o he nonpa ame ic cu e in o en age in e als, and he 95% con idence
le els we e de e mined.
Da a we e also analyzed by analysis o a iance wi h he GLM p ocedu e o SAS/STAT (SAS
Ins i u e Inc, 2004). The Tukey es was used o de ec di e ences be ween means, conside ed
signi ican p<0.05.
2.3. Resul s
2.3.1. Changes in he C accumula ed in biomass h oughou he o a ion
Resul s o non linea i o abo eg ound biomass C densi y a e shown in Table 2.2. All
pa ame e s we e signi ican a p<0.005, and he accu acy o he s a is ics was adequa e. The
a e age changes in he C accumula ed in he ee abo eg ound biomass o he h ee ee species
s udied h oughou he o a ion a e shown in Fig. 2.1. The ee g ow h a es ollowed he o de E.

INFLUENCE OF TREE SPECIES ON C SEQUESTRATION IN AFFORESTED PASTURES IN A HUMID TEMPERATE REGION
41
ni ens > E. globulus ≥ P. adia a. The h ee species con inued accumula ing C a high a es, e en
a e he common o a ion leng hs in he egion (10-15 yea s o bo h eucalyp s and 30-35 yea s o
P. adia a), which indica es he la ge po en ial o he biomass o hese species as a C sink.
Table 2.2. Abo eg ound biomass ca bon model pa ame e s and i s o age since a o es a ion.
Pa ame e es ima e (S d. e o )
Specie b0 b1 b2 RMSE Adjus . R2
E. globulus 520.3 (6.23) 0.0589 (0.0021) 2.356 (0.0325) 3.0331 0.718
E. ni ens 784.1 (10.41) 0.0393 (0.0013) 1.815 (0.0218) 2.1483 0.835
P. adia a 1569.5 (13.75) 0.0126 (0.0008) 1.466 (0.0201) 4.3544 0.788
Figu e 2.1. Changes in o al abo eg ound biomass C h oughou he o a ion. Con inuous lines indica e he i ed
Richa ds model; do ed lines a e 95% con idence le els o he mean. E. ni ens ed; E. globulus g een; P. adia a
black.
2.3.2. Changes in C accumula ed in li e h oughou he o a ion
The changes in he C accumula ed in he li e laye (and mine al soil o dep h 15 cm) o each
o he h ee species a e shown in Fig. 2.2. The a e age ends h oughou he o a ion we e i ed
by he nonpa ame ic p ocedu e desc ibed in poin 2.2. The h ee species showed di e en
pa e ns as ega ds he dynamics and he amoun s o C accumula ed a he end o he o a ion.
Thus, in acco dance wi h he highe g ow h a es o biomass, li e accumula ion occu ed ea lie (2
y a e es ablishmen ) in E. ni ens han in P. adia a and E. globulus (4-5 y a e o es
es ablishmen ). The li e C accumula ion a es ollowed he o de : E. ni ens > P. adia a > E.
globulus. Li e accumula ion was lowe han expec ed in E. globulus s ands, conside ing he high
abo eg ound ee g ow h. The co ela ions be ween he changes in c own biomass and li e laye
dynamics we e di e en o each species, and we e gene ally a he weak (n.s. o E. globulus; R2=
0.40 o E. ni ens, and R2= 0.55 o P. adia a).
CHAPTER II
42
Li e accumula ion s abilized 10 yea s a e a o es a ion by bo h Eucalyp us species, whe eas
he li e laye con inued o inc ease in ma u e P. adia a plan a ions. A he end o he o a ion, he
a e age amoun s o C in he li e laye anged om 10.1 (E. globulus, 10 y ), o 24.8 Mg ha-1 (E.
ni ens, 10 y ) and 50.9 (P. adia a, 35 y ).
Figu e 2.2. Changes in ca bon densi y accumula ion (Mg ha-1) in he li e laye and mine al soils h oughou he i s
o a ion a e a o es a ion. Da k shaded a ea: 95% con idence limi s o 0-15 cm dep h mine al soil (CAD); ligh
shaded a ea: 95% con idence limi s o ganic laye (n= 40 o each o he h ee species).
INFLUENCE OF TREE SPECIES ON C SEQUESTRATION IN AFFORESTED PASTURES IN A HUMID TEMPERATE REGION
43
2.3.3. Changes in SOC in he mine al soils a e a o es a ion
The changes in SOC densi y ela i e o ha o he pai ed pas u e (CRD) in he mine al soil o
each soil dep h laye , conside ing each species sepa a ely and oge he , a e shown in Table 2.3.
In he i s 10 yea s a e a o es a ion, losses o C in he 0-15 cm laye we e ound in all h ee ee
species, anging be ween -52.0% in P. adia a o abou -0.2% in bo h species o Eucalyp us in he
i s 5 yea s. Howe e , he ANOVA only e ealed signi ican changes in he 0-5 and 5-15 cm soil
laye s unde P. adia a, which emphasizes he high a iabili y in he Eucalyp us s ands. In he
11-15 y pe iod, he SOC con en s we e simila in a o es ed and pas u e soils o all species.
Finally, in he s ands olde han 20 y (only o P. adia a), he SOC con en s we e signi ican ly
highe in he uppe mos soil laye (0-5 cm) han in he o he laye s. No such end was de ec ed in
he 15-30 cm laye .
Table 2.3. A e age alues (and s anda d de ia ions) o ela i e di e ence in ca bon densi y (CRD, %) conside ing all
species join ly (n= 120), and each species sepa a ely (n=40). Signi ican di e ences o a gi en soil dep h a e indica ed
by di e en le e s.
Mine al soil laye s (cm)
T (yea s) 0-5 5-15 15-30 0-15 0-30
All species 0-5 -21.1 (26.7)
a -6.9 (52.8) 1.3 (42.3) -14.6 (36.8) -9.5 (33.9)
6-10 -6.2 (31.2) ab
3.5 (40.6) 10.2 (45.8) -2.0 (31.7) 1.5 (33.1)
11-15 -3.3 (38.4) ab
8.7 (73.4) 6.4 (64.8) 0.8 (47.9) 2.0 (51.8)
16-20 16.6 (49.7) bc
-4.1 (33.8) -3.2 (44.4) 1.2 (28.6) -1.1 (31.0)
>21 30.7 (29.7) c 7.8 (29.1) 3.8 (45.9)
15.5 (23.3) 9.9 (27.0)
E. globulus 0-5 -4.1 (17.8) 12.3 (43.6) 28.4 (46.4)
-0.1 (22.0) 13.4 (37.6)
6-10 -9.4 (34.8) -9.0 (45.1) -4.1 (57.9) -9.2 (39.6) -8.4 (43.6)
11-15 5.4 (45.4) 19.2 (110.4)
4.7 (84.2) 6.8 (66.5) 6.9 (72.7)
16-20 8.7 (30.0) -0.1 (38.7) -2.5 (42.8) 3.2 (24.3) -1.4 (30.2)
E. ni ens 0-5 -3.1 (18.5) 13 (34.8) 19.6 (37.4)
-0.3 (24.6) 8.0 (27.9)
6-10 -6.0 (29.8) 3.4 (41.7) -17.3 (46.8)
-1.4 (26.1) -8.6 (31.9)
11-15 -8.9 (22.4) -6.3 (29.5) 5.0 (62.8) -8.9 (21.6) -4.5 (33.7)
16-20 29.9 (71.6) -12.3 (13.8)
-28.2 (20.2)
6.6 (39.9) -7.4 (26.0)
P. adia a 0-5 -51.3 (18.6)
a -52.8 (16.5)
a -5.3 (29.5) -52.0 (16.7) a -34.1 (17.3)
a
6-10 -23.6 (29.4)
ab
-23.4 (13.1)
ab
-4.5 (18.8) -24.1 (10.6) ab -17.1 (9.0) ab
11-15 -14.3 (41.8)
ab
-16.8 (30.9)
ab
-13.8 (31.0)
-15.6 (32.6) ab -16.0 (29.7)
ab
16-20 32.5 (65.2) bc
-4.4 (28.8) bc
4.6 (47.3) 4.6 (31.4) bc 3.7 (32.6) ab
>21 28.4 (29.3) bc
13.4 (28.7) bc
10.1 (50.5)
18.9 (23.2) cd 14.7 (27.8) b
This e ec was also obse ed in ela ion o he numbe o plo s ha a e in a ce ain g oup o
losses o gains wi h espec o CRD, shown o soil dep hs o 0-15 and 15-30 cm, and conside ing
all species oge he (Fig. 2.3). Al hough he da a e ealed a high deg ee o a iabili y, bo h
ep esen a ions show a gene al end o he SOC con en in he 0-15 cm soil laye . Ca bon was
CHAPTER II
44
los om his soil laye du ing he i s 10 yea s a e a o es a ion, al hough gains we e obse ed
he ea e . Ne posi i e gains we e ound om 20 yea s onwa ds.
0-5 yea s
0
2
4
6
8
10
12
14
-80-60-40-20 0 20406080
Ca bon con en di e ence (%)
Numbe o plo s
6-10 yea s
0
2
4
6
8
10
12
14
-80 -60 -40 -20 0 20 40 60 80
Ca bon con en di e ence (%)
Numbe o plo s
11-15 yea s
0
2
4
6
8
10
12
14
-80-60-40-20020406080
Ca bon con en di e ence (5)
Numbe o plo s
16-20 yea s
0
2
4
6
8
10
12
14
-80-60-40-20 0 20406080
Ca bon con en di e ence (%)
Numbe o plo s
>21 yea s
0
2
4
6
8
10
12
14
-80-60-40-20 0 20406080
Ca bon con en di e ence (%)
Numbe o plo s
0-15 cm
15-30 cm
0-15 cm
15-30 cm
Figu e 2.3. Changes in ela i e di e ence in ca bon densi y (CRD, %) in each mine al soil laye g ouped in age
classes o 5 yea s and CRD classes o 20% o all species conside ed.
The a e age mine al soil C densi y in pas u es and a o es ed s ands, g ouped in age classes
o 10 yea s and o he h ee mine al soil laye s s udied, a e shown in Fig. 2.4. Fo di ec
compa ison o he C densi ies in each soil dep h, he alue o each soil laye was di ided by he
co esponding dep h (Mg ha-1 cm-1). The a e age SOC densi ies in pas u e sub-plo s we e
cons an , since he e we e no signi ican changes in ca bon densi ies o e ime o any o he
species s udied (p<0.001). Changes in CRD and CAD we e he e o e only due o changes in SOC
densi ies in o es subplo s, because ca bon emained cons an o a gi en soil laye in pas u e
land. The e we e no signi ican di e ences in he dis ibu ion o SOC ac oss soil dep h ei he
be ween species o ages conside ed (p<0.001). Ne e heless, he e we e signi ican di e ences in
P. adia a s ands in he uppe mine al soil laye s, as p e iously epo ed.
On he o he hand, he mean changes in CAD and he 95% con idence le els in he 0-15 cm
mine al soil (and in he li e laye ) o each o he h ee species conside ed in his s udy h oughou
hei espec i e o a ions a e shown in Fig. 2.2. Fo calcula ion o he a e age ends and
con idence le els, he nonpa ame ic p ocedu e i ing desc ibed abo e was applied. This ype o
ep esen a ion enables conside a ion o he a iabili y in he da a. Signi ican SOC losses we e
de ec ed in he i s 5-10 yea s a e a o es a ion in P. adia a s ands. The a e age losses
amoun ed o -10.1 Mg ha-1 ( o 95% o con idence le el, be ween -7.1 o -13.0), which cons i u ed
an a e age loss o -24.1% o he ini ial SOC ( o 95% o con idence le el, be ween 18.8-29.4%).
The e we e hen la ge gains in soil C, coinciding wi h signi ican accumula ion o li e , e lec ing a
change in he en i onmen al equilib ium be ween decomposi ion and p oduc ion. The a e age
compensa ion age ( he ime a which he ini ial SOC con en is eco e ed) was 20 y ( o 95% o
con idence le el, he da a anged om 14 o 25 y ) and p og essi e gains occu ed he ea e .
INFLUENCE OF TREE SPECIES ON C SEQUESTRATION IN AFFORESTED PASTURES IN A HUMID TEMPERATE REGION
51
no only a ec he mo e labile o ganic SOM compounds, bu also complex and ecalci an C
compounds (Chap e V).
Simila pa e ns o hose desc ibed abo e ha e been desc ibed in o he s udies (Table 2.6).
These s udies we e selec ed o ep esen he same land use change as desc ibed in he p esen
s udy, and o p o ide in o ma ion enabling es ima es in he sho and long- e m and a
compensa ion age. In he sho e m (<20 y ), he a e age losses we e simila o hose obse ed in
he p esen s udy. The a e age C compensa ion ages eco ded in he p esen s udy, be ween 10
and 25 yea s, we e wi hin he mos common ange epo ed in he ele an li e a u e (Table 2.6),
al hough much longe compensa ion ages (80 y ) ha e been simula ed in colde clima es han
desc ibed he e. Mo eo e , g ea e (al hough highly a iable) long- e m gains han hose obse ed
he e ha e been epo ed, al hough he ime ame conside ed was longe han in he p esen s udy
(Table 2.6).
The p esen esul s show ha he subsequen gains in SOC ook place a e canopy closu e in
he s ands. Signi ican C gains we e only eco ded in he 15 cm uppe mine al soil laye . Howe e ,
i is known ha oo u no e om ees can inco po a e o ganic ma e deepe han 30 cm (B own
& Lugo, 1990; T umbo e e al., 1995; Jackson e al., 1996; Jobbágy & Jackson, 2000), al hough C
accumula ion in oo biomass was no aken in o accoun he e. The subsoil ho izons we e e y
a iable (A2, AB, B), and he SOC con en s we e di e en , which may ha e p e en ed
iden i ica ion o any clea ends.
Fu he mo e, wi hin he same species, he SOC gains we e sligh ly highe in he s ands wi h
highe si e indexes, which e lec s he in luence o he g ea e biomass p oduc ion on li e
p oduc ion. Ne e heless, he e ec o he si e index was no able o be e alua ed accu a ely, since
si e index was a he high in mos cases. This aspec is o in e es , as clima e change is expec ed
o change si e index, and he e o e ne p ima y p oduc ion, wo ldwide, and he e ec on changes in
SOC equi ed u he in es iga ion. Soil ex u e is one o he mos impo an ac o s con olling
SOC dynamics, and SOC inc eases wi h clay con en in a o es ed soils (Mendham e al., 2003).
The p esen s udy, howe e , did no iden i y any changes in he SOC dynamics a ibu able o soil
ex u e, p obably because he soils we e a he homogeneous as ega ds his pa ame e .

CHAPTER II
52
This s udy
Mo is e al. (2007)
Thuille & Schulze (2006)
Ussi i e al. (2006)
Hooke & Comp on
Ves e dal e al. (2002)
Tu ne & Lambe (2000)
Jug e al. (1999)(1)
Ross e al. (1999)
Rich e e al. (1999)
Bashkin & Binkley (1998)
Giddens e al. (1997)
Johns on e al. (1996)
Zak e al. (1990)
Sou ce
Pinus adia a
Eucalyp us ni ens
Eucalyp us globulus
Deciduous spp.
Coni e ous spp.
Picea abies
Robinia pseudoacacea
Casua ina spp.
Pinus s obus
Que cus obu ; Picea
Eucalyp us g andis
Populus spp; Salix
Populus spp; Salix
Pinus adia a
Pinus aeda
Eucalyp us saligna
Pinus adia a
Fi e o es ypes
Que cus ellipsoidalis
Species
P
P
P
A
A
P
P
P
P
P
P
A,P
A, P
P
A
A
P
A
A
O igen
PL
PL
PL
PL
PL
PL
PL
PL
S
PL
PL
PL
PL
PL
PL
PL
PL
S
S
Re .
land
use
PP, CH
PP, CH
PP, CH
PP
PP
CH
PP
PP
CH
CH
PP, CH
LT
LT
PP
LT
PP
PP
CH
CH
App oach
0-15
0-15
0-15
100
100
0-50
0-10
0-10
0-20
0-5
0-10
0-5
0-5
0-10
0-7.5
0-10
0-10
0-10
0-10
Mine al
soil
dep
(cm)
5-13
11
8
-
-
15-60
10
10
-
5-10
15
7
10
19
6-10
-
-
5-10
8-9
Age (y )
-26.0%
(-34.4%--17.0%)
-16.7%
(-34.7%-+0.2%)
-22.2%
(-52.0%-+2.7%)
-
-
-30%
-11%
-16%
-
-45%
-40%
+17%
+50%
-13%
-18%
-
-
-10%
-31%
E ec
S. T. EFFECT
17 (14-25)(5)
(-21.4%-+27.9%)
16(4)
(-15.5%-+18.8%)
12(4)
(-15.7%-+21.7%)
-
-
80(3)
-
-
-
-
-
-
-
-
16-18
10-13
16-24(2)
20
20
(y )
COMP.
34
18
21
65
65
93-112
-
-
115
29
35
-
-
-
35
-
-
40
40
Age (y )
A, ag icul u e; P, pas u e; S, seconda y succession, PL, plan a ion; CH, ch onosequence; PP, pai ed plo s; LT, long e m s udy.
(1) Fe ilized sho o a ion plan a ions. (2) Fo 60% o he s udied si es. (3) Ob ained om simula ion model. (4) Compensa ion age o he a e age alue; (5)
Compensa ion age o
he 95% con idence in e als. (6) Mg C ha-1 y -1.
+23.5%
(+10.6%-+37.4%)
+2.2%
(-15.6%-+18.8%)
+10.8%
(+2.0%-+24.2%)
+35.6%
+24.7%
+0.24-+0.34(6)
-
-
0%
-25%
-40%
-
-
-
+22%
-
-
+40%
+35%
E ec
L. T. EFFECT
Table 2.6. Changes in uppe mine al soil ca bon a e land use change om ag icul u e o pas u e o o es epo ed in se e al e e ence s udies. Fo he alues ob ained in he
p esen s udy: sho e m (S.T.) and long e m (L.T.) e ec s show he a e age and he ange o alues p o ided by LOESS analysis. The ange o compensa ion age (Pinus
adia a) and he CRD compensa ion age (COMP.) a e also shown.
INFLUENCE OF TREE SPECIES ON C SEQUESTRATION IN AFFORESTED PASTURES IN A HUMID TEMPERATE REGION
53
2.4.4. In luence o species
The esul s o he p esen s udy e ealed impo an di e ences in he SOC dynamics ollowing
a o es a ion, a ibu able o he ee species and he associa ed ege a ion. Al hough SOC losses
we e always eco ded a e a o es a ion, in he soils unde he wo eucalyp species, losses we e
gene ally lowe and he pe iods o loss we e sho e . In he P. adia a s ands he e was clea ne
gain o SOC om 25 yea s onwa ds, because o he longe o a ion. In bo h eucalyp s ands, he
compensa ion ages we e close o he end o he o a ion, which implies no ne gains p io o cu ing
in mos cases. Longe o a ion in eucalyp s may lead o posi i e SOC gains.
Mo eo e , he a iabili y in SOC in he ea lie pe iod (0-10 y ) was much highe in bo h
Eucalyp us s ands han in P. adia a (Fig. 2.2). This was p obably due o he dea h o weeds and
he baceous species in he o es subplo because o shading, which leads o loss o SOC in all
plo s, independen ly o he ini ial condi ions. In he P. adia a plo s (Table 2.4) he e we e no
signi ican di e ences be ween he uppe and lowe pa o he CAD cu e (Fig. 2.2).
The di e en pa e ns in he SOC dynamics may be de e mined by he di e en SOM dynamics
and li e u no e o he h ee ee species s udied. Thus, i is possible ha he apid li e u no e
in bo h ypes o eucalyp us s ands p e en ed SOC losses in he i s yea s a e a o es a ion, as
also sugges ed by Ves e dal e al. (2008), and Huang e al. (2011). Howe e , he di e ences in
SOC may also be due o he di e en g ound ege a ion de elopmen in eucalyp us and pine
s ands, which a ec s he SOC ia di e en mechanisms (Lugo & B own, 1993; Sil e e al., 2004).
In he pine plan a ions, he wide c own in e cep ing sola adia ion exe s a nega i e in luence on
he g ound ege a ion ( e y la ge dec eases in he g ound ege a ion occu om he 5 h yea (Omil
e al., 2007)) and p obably also nega i ely a ec s li e decomposi ion. Thus, he highe losses o
SOC obse ed in he young pine plan a ions may be due o he lowe ans e o o ganic C o he
mine al soil, as a consequence o he lowe li e inpu s om he g ound ege a ion and he lowe
decomposi ion a e o he li e .
The opposi e occu s in he eucalyp us plan a ions, in which he highe c own ligh - ansmission
a ou s highe g ound ege a ion co e h oughou he whole o a ion, and wi h a high p esence o
g ass species (González-He nández e al., 1998; Sil a-Pando e al., 2002). The di e en g ound
ege a ion co e p obably de e mined he amoun s and he ype o li e (ae ial, oo ) in hese
plan a ions. Thus, he p esence o g ass in hese young plan a ions esul ed in g ea e
belowg ound C inpu s such as oo biomass u no e and oo exuda es (Jones e al., 2009). G ass
ma e ial is inco po a ed mo e apidly han li e laye ma e ial in o soil o ganic ma e (And ade e
al., 2008; Laungani & Knops, 2009). The lowe losses o SOC in eucalyp soils may he e o e be
due o he highe inpu s o li e om g asses in he g ound ege a ion, hus compensa ing o he
ini ial losses o SOC ollowing a o es a ion. Simila mechanisms has also been sugges ed by
Lemma e al. (2006) and Huang e al. (2011) o explain he g ea e SOC gains in soils a o es ed
wi h Pinus pa ula and E. ni ens, espec i ely.
CHAPTER II
54
Mo eo e , he C/N a ios in he mine al soil laye o he ma u e a o es ed soils unde pines
inc eased h oughou he o a ion. This e ec has also been epo ed in o he s udies (Sme hu s &
Sadanandan Nambia , 1995; Giddens e al., 1997; Jug e al., 1999; Ussi i e al., 2006), and is
p obably due he inc eased in luence o o es li e on SOM quali y h oughou he o a ion. This
would e lec a shi om o ganic inpu domina ed by g ass li e , o o es li e con aining g ea e
amoun s o ecalci an biopolyme s ( esins, waxes, sube in and cu in-de i ed compounds (Che e z
e al., 2002; O o & Simpson, 2006)). The p oduc ion o ecalci an compounds om his ype o
li e and hei elease o he mine al soil may he e o e explain he highe C/N a io in he soils
unde ma u e pine plan a ions. The highe C/N a io in he a o es ed soils may also be due o a
lowe p esence o legumes in he unde s o y ege a ion (Co beels e al., 2002) and o highe N
immobiliza ion in ees.
Howe e , he C/N a io was no highe in he eucalyp us s ands, possibly because o he
p esence o mo e g ass in he unde g ound ege a ion in hese plan a ions. Soil analyses e ealed
he p esence o mo e ca bohyd a es in he SOM in hese ma u e s ands, e lec ing di e en
sou ces o li e (possibly due o he inpu o oo li e and oo exuda es) ela i e o he mine al soil
unde pine, in which mo e ecalci an compounds we e iden i ied (Chap e V).
2.4.5. Inc easing he C sink capaci y by ee species selec ion and managemen
The da a ob ained in he p esen s udy show ha o he species s udied, E. ni ens has he
highes C sink capaci y, ollowed by E. globulus and, e y closely by P. adia a. The mean a es o
C seques a ion (biomass and soil) es ima ed in his s udy o he mos common o a ions (Table
2.5) anged be ween 8.7 and 12.6 Mg C ha-1 y -1 (a e age alue o he h ee species, 10.9 Mg C
ha-1 y -1). Conside ing ha he a o es ed a ea in no he n Spain using hese h ee species can be
es ima ed as 135000 ha o he pe iod 1994-2006 (MAPA, 2006), a o es a ion would ha e esul ed
in a sink o 1.2-1.7 Tg C y -1 (a e age 1.5 Tg C y -1), wi h espec o he Spanish CO2 emissions
(101 Tg C in he yea 2009, (MMAMRM, 2010)). This indica es he signi ican con ibu ion o
a o es a ion o he mi iga ion o CO2 emissions, and also shows ha selec ion o he ee species
is a majo ac o in luencing he C sink capaci y.
P olonga ion o he o a ion by 10 and 5 yea s o Eucalyp us and P. adia a espec i ely
esul ed in a C seques a ion a e anging be ween 10.9 and 14.2 Mg C ha-1 y -1 (a e age alue o
he h ee species, 12.7 Mg C ha-1 y -1, Table 2.5), which implies a sink o 1.6-2.3 Tg C y -1
(a e age 1.7 Tg C ha-1 y -1). These and p e ious esul s (Balboa-Mu ias e al., 2006; Diaz-Bal ei o
e al., 2009) show ha in o de o maximize he C sink capaci y, plan a ions should be managed
acco ding o he op imal ha es ing schedules o hese species. In he p esen s udy, he da a
show ha he C sink capaci y o hese plan a ions can be inc eased g ea ly by p olonging he
o a ion age.
The selec ion o ee species and he ha es scheduling may also a ou C gains in he soil.
The con ibu ion o he soil (li e plus mine al soil) o he o e all C seques a ion anged om 8 o
INFLUENCE OF TREE SPECIES ON C SEQUESTRATION IN AFFORESTED PASTURES IN A HUMID TEMPERATE REGION
55
18% (in a e age, 15%), which is simila o he inpu s epo ed by De V ies e al. (2006) and
Woodbu y e al. (2006), in Eu ope and Uni ed S a es, espec i ely and lowe han hose epo ed
by Liski e al. (2002).
Ne e heless, since hese in ensi ely managed plan a ions a e ha es ed epea edly, he
equilib ium will p obably be de e mined by he speci ic managemen o each species, pa icula ly
by he in ensi y o he ha es ing and dis u bance a e cu ing. Thus, unlike in colde clima es
(Be g e al., 2009), in hese in ensi ely managed o es s he C con ained in he li e canno be
conside ed as a medium- e m s o e o s o ed C because i may be apidly los a e clea cu ing o
si e p epa a ion. This is pa icula ly impo an in he wo Eucalyp us plan a ions, in which
managemen in sho o a ions may lead o con inuous loss o SOC. On he con a y, since
plan a ions o E. globulus a e coppiced (i.e. he oo sys em is kep wi hou any si e p epa a ion),
he subsequen o a ion will g ow as e and SOC will p obably con inue o inc ease.
Al hough he si e p epa a ion echniques ca ied ou in he egion ( ipping o holing), do no
in ol e impo an soil dis u bance, logging esidues a e o en emo ed om he si e o ene gy
p oduc ion. This educes li e inpu and nu ien e u ns (Me ino e al., 2005), which may educe
he C sink capaci y o bo h biomass and soil (Mailla d e al., 2010). Thus, ne losses o soil C ha e
been eco ded in soils subjec ed o high deg ee o dis u bance o si e p epa a ion (Pé ez-Ba allón
e al., 2001).
On he o he hand, he main limi ing nu ien s in hese plan a ions a e P and Mg. Imp o emen
o he nu i ional s a us o he plan a ion no only implies highe biomass g ow h a es, bu also
a ou s accumula ion o SOC (Tu ne e al., 2005). The applica ion o cha coal-con aining wood
ash, a by-p oduc o biomass powe plan s, is inc easingly ca ied ou in he a ea. The applica ion
o wood ash eplenishes nu ien s and enhances imbe p oduc ion (e.g. Solla-Gullon e al., 2008;
Pé ez-C uzado e al., 2011). Mo eo e , cha coal is ela i ely ecalci an and can he e o e ac as a
long- e m sink o a mosphe ic CO2 (e.g. K ull e al., 2006).
2.5. Conclusions
In his s udy an in ensi e sampling scheme was used o assess he C sink capaci y o o es
s ands o he h ee species mos commonly used in a o es a ion p og ammes in no he n Spain.
The high spa ial a iabili y in he di e en compa men s illus a es he isk o eaching w ong
conclusions abou SOC dynamics when he expe imen al design does no co e mos o he
a iabili y.
The humid empe a e clima e esul ed in C accumula ion a es as high as 9-14 Mg C ha-1 y -1
in he i s 20 y , depending on he species and he o a ion leng h. The esul s o he s udy show
how selec ion o he ee species is a majo ac o in luencing he pos a o es a ion C sink
capaci y, a ec ing he amoun s o C accumula ed in bo h biomass and soil.
CHAPTER II
56
The ole o he ee species is pa icula ly impo an du ing he i s yea s a e a o es a ion
when he li e inpu om he baceous ege a ion may compensa e o losses o SOC. The pa e ns
o SOC dynamics di e ed g ea ly in ela ion o he di e en ee species used in he a o es a ion,
and we e de e mined by ans e o C o he soil ia he oo s o he g ound ege a ion and he
u no e a e o he li e . Bo h o hese sou ces we e lowe in he pine plan a ions han in he
eucalyp us plan a ions, which may explain he highe SOC du ing he i s yea s a e a o es a ion.
The humid empe a e clima e, along wi h he lack o physically p o ec ed SOM (sandy loam
ex u e o he soils) a ou ed impo an losses o SOC in he uppe mos mine al soils du ing he
i s yea s.
The s udy p o ides accu a e in o ma ion on he success o hese a o es a ion p og ammes as
ega ds CO2 mi iga ion. To enhance he C sink capaci y, plan a ions should be managed acco ding
o op imal ha es ing schedules o he species. Elonga ion o he o a ion leng h led o la ge C
sink capaci ies in all h ee species. This is especially impo an in such in ensi ely managed
plan a ions, in which ha es ing in sho o a ions may lead o con inuous loss o SOC.
2.6. Bibliog aphy
Al a ez, E.; Fe nández Ma cos, M.L.; To ado, V. & Fe nández Sanju jo, M.J. 2008. Dynamics o
mac onu ien s du ing he i s s ages o li e decomposi ion om o es species in a
empe a e a ea (Galicia, NW Spain). Nu ien Cycling in Ag oecosys ems. 80 (3): 243-256.
And ade, H.J.; B ook, R. & Ib ahim, M. 2008. G ow h, p oduc ion and ca bon seques a ion o
sil opas o al sys ems wi h na i e imbe species in he d y lowlands o Cos a Rica. Plan and
Soil. 308 (1): 11-22.
Balboa-Mu ias, M.A.; Rod íguez-Soallei o, R.; Me ino, A. & Ál a ez-González, J.G. 2006.
Tempo al a ia ions and dis ibu ion o ca bon s ocks in abo eg ound biomass o adia a pine
and ma i ime pine pu e s ands unde di e en sil icul u al al e na i es. Fo es Ecology and
Managemen . 237 (1-3): 29-38.
Balesden , J.; Chenu, C. & Balabane, M. 2000. Rela ionship o soil o ganic ma e dynamics o
physical p o ec ion and illage. Soil and Tillage Resea ch. 53 (3-4): 215-230.
Bashkin, M.A. & Binkley, D. 1998. Changes in soil ca bon ollowing a o es a ion in Hawaii.
Ecology. 79 (3): 828-833.
Bell, M.J.; Ha ch, G.R. & B idge, B.J. 1995. E ec s o con inuous cul i a ion on Fe osols in
sub opical sou heas Queensland. I. Si e cha ac e iza ion, c op yields and soil chemical
s a us. Aus alian Jou nal o Ag icul u al Resea ch. 46 (1): 237-253.
Be g, B. 2000. Li e decomposi ion and o ganic ma e u no e in no he n o es soils. Fo es
Ecology and Managemen . 133 (1-2): 13-22.
Be g, B.; Johansson, M.B.; Nilsson, A.; Gunde sen, P. & No ell, L. 2009. Seques a ion o ca bon
in he humus laye o Swedish o es s—di ec measu emen s. Can J Fo Res. 39: 962-975.
Be h ong, S.T.; Jobbágy, E.G. & Jackson, R.B. 2009. A global me a-analysis o soil exchangeable
ca ions, pH, ca bon, and ni ogen wi h a o es a ion. Ecological Applica ions. 19 (8): 2228-
2241.
Blake, G.R. & Ha ge, K.H. 1986. Bulk densi y. En: Me hods o soil analysis. Ed. A. Klu e, 2nd
Edn., ASA and SSAA, Madison, WI. 363-375 pp.

INFLUENCE OF TREE SPECIES ON C SEQUESTRATION IN AFFORESTED PASTURES IN A HUMID TEMPERATE REGION
57
B own, S. & Lugo, A.E. 1990. E ec s o o es clea ing and succession on he ca bon and ni ogen
con en o soils in Pue o Rico and US Vi gin Islands. Plan and Soil. 124 (1): 53-64.
Ca nei o, M.; Se ão, V.; Fabião, A.; Madei a, M.; Balsemão, I. & Hilá io, L. 2009. Does ha es
esidue managemen in luence biomass and nu ien accumula ion in unde s o y ege a ion o
Eucalyp us globulus Labill. plan a ions in a Medi e anean en i onmen ? Fo es Ecology and
Managemen . 257 (2): 527-535.
Ce li, C.; Celi, L.; Kaise , K.; Guggenbe ge , G.; Johansson, M.B.; Cigne i, A. & Zanini, E. 2008.
Changes in humic subs ances along an age sequence o No way sp uce s ands plan ed on
o me ag icul u al land. O ganic Geochemis y. 39 (9): 1269-1280.
Che e z, B.S.; Salloum, M.J.; Deshmukh, A.P. & Ha che , P.G. 2002. S uc u al componen s o
humic acids as de e mined by chemical modi ica ions and ca bon-13 NMR, py olysis-, and
he mochemolysis-gas ch oma og aphy/mass spec ome y. Soil Science Socie y o Ame ica
Jou nal. 66 (4): 1159-1171.
Conan , R.T.; Smi h, G.R. & Paus ian, K. 2003. Spa ial a iabili y o soil ca bon in o es ed and
cul i a ed si es: Implica ions o change de ec ion. Jou nal o En i onmen al Quali y. 32: 278-
286.
Con eh, A.; Le oy, R.D.B. & Blai , G.J. 1997. Dynamics o o ganic ma e in soil as de e mined by
a ia ions in 13C/12C iso opic a ios and ac iona ion by ease o oxida ion. Aus alian Jou nal
o Soil Resea ch. 35 (4): 881-890.
Co beels, M.; O’Connell, A.M.; McMu ie, R.E.; G o e, T.S. & Mendham, D.S. 2002. Modelling
changes in ni ogen mine alisa ion ollowing con e sion o imp o ed pas u e o eucalyp
plan a ion. Ag onomie. 22 (7-8): 801-815.
Co e, M.D.; Schnabel, R.R. & Sha e , J.A. 1999. E alua ion o soil o ganic ca bon unde o es s,
cool-season and wa m-season g asses in he no heas e n US. Soil Biology and
Biochemis y,. 31 (11): 1531-1539.
Co ing on, W.W. 1981. Changes in o es loo o ganic ma e and nu ien con en ollowing clea
cu ing in no he n ha dwoods. Ecology. 62 (1): 41-48.
Da idson, E.A. & Acke man, I.L. 1993. Changes in Soil Ca bon In en o ies Following Cul i a ion o
P e iously Un illed Soils. Biogeochemis y. 20 (3): 161-193.
De V ies, W.I.M.; Reinds, G.J.; Gunde sen, P.E.R. & S e ba, H. 2006. The impac o ni ogen
deposi ion on ca bon seques a ion in Eu opean o es s and o es soils. Global Change
Biology. 12 (7): 1151-1173.
De wile , R.P. 1986. Land use change and he global ca bon cycle: he ole o opical soils.
Biogeochemis y. 2 (1): 67-93.
Diaz-Bal ei o, L.; Be omeu, M. & Be omeu, M. 2009. Op imal ha es scheduling in Eucalyp us
plan a ions: A case s udy in Galicia (Spain). Fo es Policy and Economics. 11 (8): 548-554.
Don, A.; Rebmann, C.; Kolle, O.; Sche e -Lo enzen, M. & Schulze, E.D. 2009. Impac o
a o es a ion-associa ed managemen changes on he ca bon balance o g assland. Global
Change Biology. 15 (8): 1990-2002.
EU 1992. COUNCIL REGULATION (EEC) Nº 2080/92 o 30 June 1992 Ins i u ing a Comuni y aid
Scheme o Fo es y Measu es in Ag icul u e.
Fea nside, P.M. & Ba bosa, R.I. 1998. Soil ca bon changes om con e sion o o es o pas u e in
B azilian Amazonia. Fo es Ecology and Managemen . 108 (1-2): 147-166.
Fe nández-Núñez, E.; Riguei o-Rod íguez, A. & Mosque a-Losada, M.R. 2010. Ca bon alloca ion
dynamics one decade a e a o es a ion wi h Pinus adia a D. Don and Be ula alba L. unde
wo s and densi ies in NW Spain. Ecological Enginee ing. 35: 876-890
Giddens, K.M.; Pa i , R.L. & Pe ci al, H.J. 1997. Compa ison o some soil p ope ies unde Pinus
adia a and imp o ed pas u e. New Zealand Jou nal o Ag icul u al Resea ch. 40 (3): 409-
416.
CHAPTER II
58
Glase , B.; Tu ion, M.B.; Solomon, D.; Ni, A. & Zech, W. 2000. Soil o ganic ma e quan i y and
quali y in moun ain soils o he Alay Range, Ky gyzia, a ec ed by land use change. Biology
and Fe ili y o Soils. 31 (5): 407-413.
Goid s, E.; Van Wesemael, B. & C uci ix, M. 2009. Magni ude and sou ces o unce ain ies in soil
o ganic ca bon (SOC) s ock assessmen s a a ious scales. Eu opean Jou nal o Soil
Science. 60 (5): 723-739.
Golchin, A.; Oades, J.M.; Skjems ad, J.O. & Cla ke, P. 1994. Soil s uc u e and ca bon cycling.
Aus alian Jou nal o Soil Resea ch. 32 (5): 1043-1068.
González-He nández, M.P.; Sil a-Pando, F.J. & Jiménez, M.C. 1998. P oduc ion pa e ns o
unde s o y laye s in se e al Galician (NW Spain) woodlands: Seasonali y, ne p oduc i i y and
enewal a es. Fo es Ecology and Managemen . 109 (1-3): 251-259.
Guggenbe ge , G. & Zech, W. 1999. Soil o ganic ma e composi ion unde p ima y o es , pas u e,
and seconda y o es succession, Region Hue a No e, Cos a Rica. Fo es Ecology and
Managemen . 124 (1): 93-104.
Guo, L.B. & Gi o d, R.M. 2002. Soil ca bon s ocks and land use change: a me a analysis. Global
Change Biology. 8 (4): 345-360.
Guo, L.B.; Wang, M. & Gi o d, R.M. 2007. The change o soil ca bon s ocks and ine oo
dynamics a e land use change om a na i e pas u e o a pine plan a ion. Plan and Soil. 299
(1): 251-262.
Hobbie, S.E.; Ogdahl, M.; Cho o e , J.; Chadwick, O.A.; Oleksyn, J.; Zy kowiak, R. & Reich, P.B.
2007. T ee species e ec s on soil o ganic ma e dynamics: he ole o soil ca ion
composi ion. Ecosys ems. 10 (6): 999-1018.
Hooke , T.D. & Comp on, J.E. 2003. Fo es ecosys em ca bon and ni ogen accumula ion du ing
he i s cen u y a e ag icul u al abandonmen . Ecological Applica ions. 13 (2): 299-313.
Huang, Z.; Da is, M.R.; Cond on, L.M. & Clin on, P.W. 2011. Soil ca bon pools, plan bioma ke s
and mean ca bon esidence ime a e a o es a ion o g assland wi h h ee ee species. Soil
Biology and Biochemis y. in p ess.
Hugge , R.J. 1998. Soil ch onosequences, soil de elopmen , and soil e olu ion: a c i ical e iew.
Ca ena. 32 (3-4): 155-172.
IPPC 2007. Clima e change 2007: Syn hesis epo . Con ibu ion o Wo king G oups I, II and III o
he Fou h Assessmen Repo o he In e go e nmen al Panel on Clima e Change. Co e
W i ing Team, Pachau i, R.K. and Reisinge , A. (Eds.). h p://ipcc-
wg1.uca .edu/wg1/docs/WG1AR4_SPM_Plena yApp o ed.pd Edn., Uni ed Na ions O ice,
Gene a, Swi ze land. 104 pp.
IUSS Wo king G oup WRB 2006. Wo ld e e ence base o soil esou ces 2006. Wo ld Soil
Resou ces Repo s No. 103 FAO, Rome. 128 pp.
Jackson, R.B.; Banne , J.L.; Jobbágy, E.G.; Pockman, W.T. & Wall, D.H. 2002. Ecosys em ca bon
loss wi h woody plan in asion o g asslands. Na u e. 418 (6898): 623-626.
Jackson, R.B.; Canadell, J.; Ehle inge , J.R.; Mooney, H.A.; Sala, O.E. & Schulze, E.D. 1996. A
global analysis o oo dis ibu ions o e es ial biomes. Oecologia. 108 (3): 389-411.
Jandl, R.; Lindne , M.; Ves e dal, L.; Bauwens, B.; Ba i z, R.; Hagedo n, F.; Johnson, D.W.;
Minkkinen, K. & By ne, K.A. 2007. How s ongly can o es managemen in luence soil ca bon
seques a ion? Geode ma. 137 (3-4): 253-268.
Jobbágy, E.G. & Jackson, R.B. 2000. The e ical dis ibu ion o soil o ganic ca bon and i s ela ion
o clima e and ege a ion. Ecological Applica ions. 10 (2): 423-436.
Johnson, D.W. 1992. E ec s o o es managemen on soil ca bon s o age. Wa e , Ai , & Soil
Pollu ion. 64 (1): 83-120.
INFLUENCE OF TREE SPECIES ON C SEQUESTRATION IN AFFORESTED PASTURES IN A HUMID TEMPERATE REGION
59
Johns on, M.H.; Homann, P.S.; Engs om, J.K. & G igal, D.F. 1996. Changes in ecosys em ca bon
s o age o e 40 yea s on an old- ield/ o es landscape in eas -cen al Minneso a. Fo es
Ecology and Managemen . 83 (1-2): 17-26.
Jones, D.L.; Nguyen, C. & Finlay, R.D. 2009. Ca bon low in he hizosphe e: ca bon ading a he
soil- oo in e ace. Plan and Soil. 321 (1): 5-33.
Judd, T.S.; A iwill, P.M. & Adams, M.A. 1996. Nu ien concen a ions in Eucalyp us: a syn hesis in
ela ion o di e ences be ween axa, si es and componen s. En: Nu i ion o Eucalyp us. Eds.
P.M. A iwill & M.A. Adams, CISRO Publishing, Collingwood, Aus alia. 123-154 pp.
Jug, A.; Makeschin, F.; Reh uess, K.E. & Ho mann-Schielle, C. 1999. Sho - o a ion plan a ions o
balsam popla s, aspen and willows on o me a able land in he Fede al Republic o Ge many.
III. Soil ecological e ec s. Fo es Ecology and Managemen . 121 (1-2): 85-99.
Kane a, S. & Smolande , A. 2007. Mic obial ac i i ies in o es loo laye s unde sil e bi ch,
No way sp uce and Sco s pine. Soil Biology and Biochemis y. 39 (7): 1459-1467.
Kasel, S.; Singh, S.; Sande s, G.J. & Benne , L.T. 2011. Species-speci ic e ec s o na i e ees on
soil o ganic ca bon in biodi e se plan ings ac oss no h-cen al Vic o ia, Aus alia. Geode ma.
161 (1-2): 95-106.
Ki schbaum, M.U.F.; Guo, L.B. & Gi o d, R.M. 2008. Why does ain all a ec he end in soil
ca bon a e con e ing pas u es o o es s? A possible explana ion based on ni ogen
dynamics. Fo es Ecology and Managemen . 255 (7): 2990-3000.
K ull, E.S.; Swans on, C.W.; Skjems ad, J.O. & McGowan, J.A. 2006. Impo ance o cha coal in
de e mining he age and chemis y o o ganic ca bon in su ace soils. Jou nal o Geophysical
Resea ch. 111 (G04001): 1-9.
Laganiè e, J.; Ange s, D.A. & Pa é, D. 2010. Ca bon accumula ion in ag icul u al soils a e
a o es a ion: a me a‐analysis. Global Change Biology. 16 (1): 439-453.
Laungani, R. & Knops, J.M.H. 2009. The impac o co‐occu ing ee and g assland species on
ca bon seques a ion and po en ial bio uel p oduc ion. GCB Bioene gy. 1 (6): 392-403.
Lei ós, M.C.; T asa -Cepeda, C.; Seoane, S. & Gil-So es, F. 2000. Biochemical p ope ies o acid
soils unde climax ege a ion (A lan ic oakwood) in an a ea o he Eu opean empe a e-humid
zone (Galicia, NW Spain): gene al pa ame e s. Soil Biology and Biochemis y. 32 (6): 733-
745.
Lemma, B.; Kleja, D.B.; Nilsson, I. & Olsson, M. 2006. Soil ca bon seques a ion unde di e en
exo ic ee species in he sou hwes e n highlands o E hiopia. Geode ma. 136 (3-4): 886-898.
Lemma, B.; Nilsson, I.; Kleja, D.B.; Olsson, M. & Knicke , H. 2007. Decomposi ion and subs a e
quali y o lea li e s and ine oo s om h ee exo ic plan a ions and a na i e o es in he
sou hwes e n highlands o E hiopia. Soil Biology and Biochemis y. 39 (9): 2317-2328.
Liski, J.; Pe uchoud, D. & Ka jalainen, T. 2002. Inc easing ca bon s ocks in he o es soils o
wes e n Eu ope. Fo es Ecology and Managemen . 169 (1-2): 159-175.
Lugo, A.E. & B own, S. 1993. Managemen o opical soils as sinks o sou ces o a mosphe ic
ca bon. Plan and Soil. 149 (1): 27-41.
Mailla d, É.P.; Munson, D. & Alison, D. 2010. Soil ca bon s ocks and ca bon s abili y in a wen y-
yea -old empe a e plan a ion. Soil Science Socie y o Ame ica Jou nal. 74 (5): 1775-1785.
Mann, L.K. 1986. Changes in soil ca bon s o age a e cul i a ion. Soil Science. 142 (5): 279-288.
MAPA 2006. Fo es ación de Tie as Ag ícolas: Análisis de su e olución y con ibución a la ijación
de ca bono y al uso acional de la ie a Spanish Minis y o Ag icul u e, Fishe ies and Food,
Mad id (Spain).
Ma ín-Spio a, E.; Sil e , W.L.; Swans on, C.W. & Os e ag, R. 2009. Soil o ganic ma e dynamics
du ing 80 yea s o e o es a ion o opical pas u es. Global Change Biology. 15 (6): 1584-
1597.
CHAPTER II
60
Ma ius, C.; Hö e , H.; Ga cia, M.V.B.; Römbke, J. & Hanaga h, W. 2004b. Li e all, li e s ocks
and decomposi ion a es in ain o es and ag o o es y si es in cen al Amazonia. Nu ien
Cycling in Ag oecosys ems. 68 (2): 137-154.
Ma ius, C.; Hö e , H.; Ga cia, M.V.B.; Römbke, J.; Fö s e , B. & Hanaga h, W. 2004a.
Mic oclima e in ag o o es y sys ems in cen al Amazonia: does canopy closu e ma e o soil
o ganisms? Ag o o es y Sys ems. 60 (3): 291-304.
Mendham, D.S.; O'Connell, A.M. & G o e, T.S. 2003. Change in soil ca bon a e land clea ing o
a o es a ion in highly wea he ed la e i ic and sandy soils o sou h-wes e n Aus alia.
Ag icul u e, Ecosys ems & En i onmen . 95 (1): 143-156.
Me ino, A.; Balboa, M.A.; Rod íguez-Soallei o, R. & González, J.G. 2005. Nu ien expo s unde
di e en ha es ing egimes in as -g owing o es plan a ions in sou he n Eu ope. Fo es
Ecology and Managemen . 207 (3): 325-339.
Me ino, A.; Fe nández-López, A.; Solla-Gullón, F. & Edeso, J.M. 2004. Soil changes and ee
g ow h in in ensi ely managed Pinus adia a in no he n Spain. Fo es Ecology and
Managemen . 196 (2-3): 393-404.
Me ino, A.; López, Á.R.; B añas, J. & Rod íguez-Soallei o, R. 2003. Nu i ion and g ow h in newly
es ablished plan a ions o Eucalyp us globulus in no hwes e n Spain. Annals o Fo es
Science. 60 (6): 509-517.
MMAMRM 2010. In en a io de gases de e ec o in e nade o de España. Suma io de esul ados
Minis e io de Medio Abien e, Medio Ru al y Ma ino. Sec e a ía de Es ado de Cambio
Climá ico, Mad id (Spain).
Mo is, S.J.; Bohm, S.; Haile‐Ma iam, S. & Paul, E.A. 2007. E alua ion o ca bon acc ual in
a o es ed ag icul u al soils. Global Change Biology. 13 (6): 1145-1156.
Mu y, D.; Ki schbaum, M.U.F.; Mcmu ie, R.E. & Mcgil ay, H. 2002. Does con e sion o o es o
ag icul u al land change soil ca bon and ni ogen? A e iew o he li e a u e. Global Change
Biology. 8 (2): 105-123.
Neill, C.; Melillo, J.M.; S eudle , P.A.; Ce i, C.C.; de Mo aes, J.F.L.; Piccolo, M.C. & B i o, M.
1997. Soil ca bon and ni ogen s ocks ollowing o es clea ing o pas u e in he sou hwes e n
B azilian Amazon. Ecological Applica ions. 7 (4): 1216-1225.
Nilsson, S. & Schop hause , W. 1995. The ca bon-seques a ion po en ial o a global a o es a ion
p og am. Clima ic Change. 30 (3): 267-293.
Oades, J.M. 1988. The e en ion o o ganic ma e in soils. Biogeochemis y. 5 (1): 35-70.
Omil, B.; Mosque a-Losada, R. & Me ino, A. 2007. Responses o a Non N-Limi ed Fo es
Plan a ion o he Applica ion o Alkaline-S abilized Dewa e ed Dai y Fac o y Sludge. Jou nal
o en i onmen al quali y. 36 (6): 1765-1774.
Os e ag, R.; Ma ín-Spio a, E.; Sil e , W.L. & Schul en, J. 2008. Li e all and decomposi ion in
ela ion o soil ca bon pools along a seconda y o es ch onosequence in Pue o Rico.
Ecosys ems. 11 (5): 701-714.
O o, A. & Simpson, M.J. 2006. Sou ces and composi ion o hyd olysable alipha ic lipids and
phenols in soils om wes e n Canada. O ganic Geochemis y. 37 (4): 385-407.
Paul, K.I. & Polglase, P.J. 2004. P edic ion o decomposi ion o li e unde eucalyp s and pines
using he FullCAM model. Fo es Ecology and Managemen . 191 (1-3): 73-92.
Paul, K.I.; Polglase, P.J.; Nyakuengama, J.G. & Khanna, P.K. 2002. Change in soil ca bon
ollowing a o es a ion. Fo es Ecology and Managemen . 168 (1-3): 241-257.
Paus ian, K.; Six, J.; Ellio , E.T. & Hun , H.W. 2000. Managemen op ions o educing CO2
emissions om ag icul u al soils. Biogeochemis y. 48 (1): 147-163.
Pé ez-Ba allón, P.; Ou o, G.; Macías, F. & Me ino, A. 2001. Ini ial mine aliza ion o o ganic ma e
in a o es plan a ion soil ollowing di e en logging esidue managemen echniques. Annals
o Fo es Science. 58: 807-818.
IMPROVEMENT IN ACCURACY OF ABOVEGROUND BIOMASS ESTIMATION IN EUCALYPTUS NITENS PLANTATIONS:
EFFECT OF BOLE SAMPLING INTENSITY AND EXPLANATORY VARIABLES
67
p obabili y p opo ional o a gi en dimension. This was he case o Kleinn and Pelz, (1987), who
chose disks wi h a p obabili y o selec ion p opo ional o es ima ed olume. On he o he hand, he
PW me hod is p e e ed o la ge ees in si es wi h di icul access, as esh weighing o he whole
s em is qui e labo ious and ime consuming (Snowdon e al., 2000). In he CW me hod, he
dis ibu ion o mois u e along he s em is he main sou ce o e o o d y weigh es ima ion,
whe eas in he PW me hod, i is he a ia ion in basic densi y along he bole heigh ha a ec s ha
e o . In bo h cases, sampling in ensi y and dis ibu ion should gua an ee a sui able desc ip ion o
he a iabili y in mois u e con en and speci ic densi y.
Diame e a b eas heigh (d) and o al heigh (h) a e he mos common independen a iables
used in biomass eg ession, because o hei ease o measu emen and p edic i e capaci y
(Pa esol, 1999; Snowdon e al., 2000). Howe e , because o he cu en inc easing in e es in
ob aining accu a e p edic ions o c own ac ions o bioene gy, nu ien s abili y and sil icul u al o
ecological s udies, he e is a co esponding inc easing in e es in c own biomass modelling. Some
au ho s ha e obse ed ha he use o c own a iables as explana o y a iables imp o es he
accu acy o biomass equa ions (Sa oo & Madgwick, 1982; An ónio e al., 2007). In biomass s udies
in which high p ecision is equi ed o c own ac ions, and des uc i e sampling canno be applied,
highly accu a e models a e equi ed.
The objec i es o he p esen s udy we e: (i) o ob ain biomass es ima ion ools o a as
g owing species, Eucalyp us ni ens, in no hwes e n Spain, conside ing he mos comple e se o
abo eg ound componen s; (ii) o e alua e he bias and accu acy o wood biomass es ima ion o
di e en in ensi ies o sys ema ic subsampling ac oss he s em and wo a io- ype es ima o s
(d y/ esh weigh and d y mass/ esh olume), (iii) o e alua e he inc eased accu acy de i ed om
he inclusion o c own a iables in he es ima ion o indi idual ee biomass componen s, and (i ) o
e alua e he abili y o he p oposed equa ions o es ima e he p opo ion o each biomass
componen o e o al abo eg ound biomass, o a ange o diame e classes.
3.2. Ma e ial and me hods
3.2.1. S udy si e and ees sampled
This s udy was ca ied ou in no hwes e n Spain, in an inland a ea loca ed a ele a ions o 500
o 1000 m.a.s.l., wi h a e age p ecipi a ion o 900-1200 mm and a e age annual empe a u e o
12-13ºC (Ma ínez Co izas & Pé ez Albe i, 1999). Al hough os occu ence limi s plan ing o he
mos common Eucalyp us species in Spain (Eucalyp us globulus Labill.), Eucalyp us ni ens (Deane
& Maiden) Maiden was success ully in oduced in he mid 1990s, p o iding yields o 15-50 m3 ha-1
y -1 (Pé ez-C uzado, 2009).

CHAPTER III
68
As he aim o he p esen s udy was o cons uc biomass models ha a e as ep esen a i e as
possible, sampling consis ed o wo phases: (1) s udy o he a iabili y o he mos commonly used
independen a iables in biomass equa ions a ee le el (d and h, see below) ac oss he
dis ibu ion a ea, and (2) des uc i e sampling o ees co e ing he obse ed ange (Pa esol,
1999). Fo his pu pose, 76 plo s we e es ablished (see loca ion in Fig. 3.1), co e ing he obse ed
ange o ages and si e quali ies, wi h a minimum plo size o 314 m2, which is gene ally sui able o
biomass es ima ion p ocedu es in plan a ions (Sa oo & Madgwick, 1982).
Figu e 3.1. Loca ion o he measu ed plo s (do s) and he dis ibu ion o Eucalyp us ni ens in no h-wes e n Spain
(shaded a ea).
A sample size o 40 ees was chosen because o he low a iabili y in si e condi ions and
densi ies o plan a ions, mos o which we e es ablished wi h he MacAlis e p o enance. The
sampled ees we e chosen in wo s eps, wo ees pe diame e and heigh class we e i s
selec ed, and 16 addi ional ees we e hen chosen, conside ing he ela i e impo ance o each
diame e class in he popula ion. The aim o his p ocedu e was o co e he ull ange o ee size,
which is shown o heigh and diame e in Fig. 3.2. T ees we e elled in 12 plo s, in which he
alues o he quad a ic mean diame e and d o he ees sampled was simila ; undamaged,
heal hy ees ha ep esen ed he dominan and codominan s a a, we e chosen. The a e age
s anda d de ia ion and ange o ep esen a i e s and and single ee a iables, o bo h he
popula ion and he sample a e shown in Table 3.1. The a iabili y in c own a iables was simila o
ha obse ed in s em a iables, unlike in o he s udies (Sa oo & Madgwick, 1982).
IMPROVEMENT IN ACCURACY OF ABOVEGROUND BIOMASS ESTIMATION IN EUCALYPTUS NITENS PLANTATIONS:
EFFECT OF BOLE SAMPLING INTENSITY AND EXPLANATORY VARIABLES
69
0
5
10
15
20
25
30
35
40
45
50
55
0 5 10 15 20 25 30 35 40 45 50 55 60 65
d (cm)
h (m)
c
Figu e 3.2. Heigh -diame e dis ibu ion o Eucalyp us ni ens in an ini ial in en o y in no h-wes e n Spain.
Table 3.1. S a is ics o s and and single ee a iables in he popula ion (76 plo s, 3864 ees) and he sample plo s
(12 plo s, 40 ees).
S and a iables Indi idual ee a iables
SI (m) N (s ems ha-1) Age (y ) d (cm) h (m)
All plo s A e age (S d. de .) 15.3 (4.4) 1089 (280) 9.5 (4.2) 18.5 (7.5) 20.2 (6.4)
Range 8.8 - 20.8 446 - 1560 2 - 18 1.0 - 59.6 2.2 - 48.3
Sample plo s A e age (S d. de .) 15.7 (2.7) 1101 (223) 10.2 (2.8) 19.5 (7.7) 19.3 (5.5)
Range 9.8 - 18.9 446 - 1401 2 - 13 1.1 - 47.0 2.4 - 35.1
whe e SI is he si e index (m a e e ence age o 6 yea s); N is s and densi y (s ems ha-1), d is diame e a b eas
heigh (cm), and h is he o al heigh (m).
The ollowing a iables we e measu ed in he sample ees while s ill s anding: diame e a
b eas heigh (d, cm) and s ump diame e a 0.15 m (ds , cm), bo h measu ed in wo pe pendicula
di ec ions o he nea es mm; o al heigh (h, m) and li e c own base heigh , de ined as he heigh
o he i s li e b anch inse ion in he s em (hcb, m), bo h measu ed o he nea es dm; c own
diame e (dc, m) measu ed in wo pe pendicula di ec ions ollowing he ca dinal poin s o he
nea es cm. Li ing c own leng h (hc, m) was es ima ed as di e ence be ween o al heigh (h) and
li e c own basis heigh (hcb, m). C own olume ( c) was calcula ed om hc and dc by assimila ing
he c own shape o an ellipsoid [3.1]. Desc ip i e s a is ics o hese a iables a e shown in Table
3.2.












223
42
cc
c
hd

[3.1]
CHAPTER III
70
3.2.2. Ra io ype es ima o s and subsampling
The elled ees we e cu in o 0.5 m logs o a small-end diame e o 7 cm. The logs we e
weighed esh and a sys ema ic subsample o one 5 cm-disk in he bo om pa o each log was
aken, also conside ing a u he disk a he op o he s em. Sample disks we e weighed esh and
anspo ed o he labo a o y in plas ic bags. The o e and unde -ba k diame e s o he disks we e
measu ed in wo di ec ions and he ba k and wood we e hen sepa a ed and weighed.
Fo each disk, he d y wood weigh was measu ed a e o en d ying a 105ºC o cons an
weigh and he a io o he d y/ esh weigh o he wood was de e mined. Only one composi e
sample pe ee was conside ed o he ba k. F esh ba k o all disks was weighed join ly, and d ied
o de e mine d y ba k weigh , hus enabling he a io o d y/ esh weigh o ba k o be ob ained o
each ee.
Table 3.2. Desc ip i e s a is ics o sampled ees.
Va iable A e age Maximum Minimum S . De .
Independen a iables
d (cm) 20.84 41.55 3.95 10.04
ds (cm) 25.63 52.40 6.60 12.13
h (m) 19.94 30.80 4.40 7.27
hcb (m) 12.55 20.60 2.80 4.68
hc (m) 7.39 19.80 1.20 4.21
dc (cm) 3.50 8.55 1.25 1.66
c (m3) 81.78 566.5 1.00 129.3
Dependen a iables (kg ee-1)
Wl 10.73 48.85 0.28 12.94
W 4.15 23.33 0.18 5.10
W b 4.40 18.46 0.04 4.53
WTb 13.57 75.65 1.29 18.71
Ww 168.43 599.5 0 176.9
Wb 24.59 111.3 0 28.33
Wdb 11.29 68.28 0.03 13.64
W o 237.2 838.2 2.54 248.1
De ini ions o independen and dependen a iables a e gi en in sec ion 3.2.2. W o e e s o o al abo eg ound
biomass.
The d y weigh o wood and o ba k in each log was calcula ed om he a e age a ios
calcula ed o he delimi ing disks. The o al wood (Ww, o a small-end diame e o e ba k o 7cm)
and ba k (Wb, e alua ed ill he h eshold diame e conside ed o wood) d y biomass in each ee
was calcula ed as sum o he biomass o each log.
Fou biomass ac ions we e conside ed o he c own: hick b anches (WTb, diame e s o e
ba k 2-7cm), which also include he ops o he boles, hin b anches (W b, diame e s o e ba k 0.5-
2cm), wigs (W , diame e less han 0.5 cm) and lea es (Wl). Dead b anches in he s em (Wdb) is
IMPROVEMENT IN ACCURACY OF ABOVEGROUND BIOMASS ESTIMATION IN EUCALYPTUS NITENS PLANTATIONS:
EFFECT OF BOLE SAMPLING INTENSITY AND EXPLANATORY VARIABLES
71
also an impo an ac ion in E. ni ens. C own biomass was i s ac ioned in he ield in o h ee
g oups: WTb, Wdb and he sum o W b, W and Wl, and hen weighed esh, wi h a balance, o he
nea es 10 g. A subsample o 10-15% o esh weigh o each ac ion was aken o ep esen he
op, medium and bo om pa o he c own. These subsamples we e weighed in he ield, wi h
scales, o he nea es 0.01 g.
The composi e subsample o W b, W and Wl, was ac ioned and weighed in he labo a o y and
he p opo ion o each ac ion was de e mined o enable es ima ion o he esh weigh o each
c own ac ion. The d y weigh o each ac ion was hen es ima ed om he d y/ esh weigh a ios.
3.2.3. Me hodologies o bole mass es ima ion
The in o ma ion ob ained enabled compa ison o wo me hods o es ima ing bole mass o
weigh a a ange o sampling in ensi ies. The CW me hod consis ed o de e mining he comple e
s em weigh and es ima ing d y mass om disks. Disk subsampling in ensi y was modi ied
conside ing a se ies o in e -disk dis ances which we e mul iples o 0.5. Fo each in e -disk
dis ance es ed, he e we e se e al solu ions, depending on he heigh o he i s sec ion
conside ed. Fo he logs be ween wo disks, he d y weigh es ima ion was calcula ed om he
a e age d y weigh wood a io o each disk, and o basal and e minal logs he disks immedia ely
abo e o below he log we e conside ed.
Fo he PW me hod, i was conside ed ha only one pa o he s em was weighed, and o he
es o he ee he olume was calcula ed om diame e unde ba k measu ed e e y 0.5 m along
he s em and by use o he Smalian o mula. The leng h o he weighed and cubed log was made
o ange be ween 0.5 m and he o al s em heigh (up o a small-end diame e o 7 cm), conside ing
a a iable posi ion o he log along he s em. The esh weigh o he log was ans o med o d y
weigh by conside ing he mois u e con en de i ed om he whole se o disks aken each 0.5 m.
Volume o d y weigh a ios we e hen used o es ima e he o al d y mass o he s em by
mul iplying by he calcula ed olumes.
Bo h me hods and sampling in ensi ies we e compa ed wi h he esul s ob ained by he CW
me hod and disk equidis ance o 0.5 m, conside ing he ela i e di e ence in he biomass
es ima ion o each ee [3.2].


100

W
WW
ˆ
RD [3.2]
whe e Ŵ is he p edic ed bole mass alue wi h each sampling me hodology and in ensi y.
The combina ions o in e -disk dis ances, weighed log leng hs and s a ing poin along he bole
p o ided a ela i e di e ence alue, and hese we e plo ed agains subsampling in ensi y o
di e en diame e classes. The 95% con idence in e als we e ob ained conside ing a no mal
CHAPTER III
72
dis ibu ion o di e en classes o sampling in ensi y. The de aul conside a ion o he bo om disk
(CW me hod) o he bo om log (PW me hod) was conside ed sepa a ely o compa ison.
3.2.4. Models and i
Models o p edic ing biomass o ee componen s a e usually based on he allome ic
ela ionship [3.3] be ween ee biomass and ee a iables. This was hen used as he basic o m
o he models o be i ed (Zianis & Mencuccini, 2004).
1n2 b
n
b
11i ·...·x·xbW 
 [3.3]
whe e Wi is he d y mass biomass o he ac ion i and xn a e he independen a iables.
The model i ing was ca ied ou in wo s eps. Fi s , each biomass ac ion was i ed
indi idually conside ing each independen a iable and hei combina ions, by use o he minimum
gene alized squa es in he MODEL p ocedu e o SAS/STAT® (SAS Ins i u e Inc, 2004). As ini ial
pa ame e s in he i e a ion p ocess, a p e ious linea i was ca ied ou o all combina ions o
a iables, wi h he linea ized allome ic model (Pa esol, 2001), by use o he REG p ocedu e o
SAS/STAT®. In selec ing he bes model o each amily o equa ions, he ollowing s a is ics we e
calcula ed o each equa ion: bias (MRES, [3.4]), oo mean squa e e o (RMSE, [3.5]) and
adjus ed de e mina ion coe icien (R2Adj., [3.6]).

N
W
ˆ
W
RESM
N
1i
ii



 [3.4]

pN
W
ˆ
W
RMSE
N
1i
2
ii



 [3.5]






























pN
1N
·
WW
W
ˆ
W
Adj.R N
1i
2
ii
N
1i
2
ii
2 [3.6]
whe e N is he numbe o da a used in he i ing, p is he numbe o pa ame e s o be es ima ed,
i
W is he a e age alue o he dependen a iable.
In he second s ep, each amily o equa ions was i ed simul aneously by he seemingly
un ela ed eg essions me hod (SUR) o gua an ee he addi i i y o he sys em (Pa esol, 2001).

IMPROVEMENT IN ACCURACY OF ABOVEGROUND BIOMASS ESTIMATION IN EUCALYPTUS NITENS PLANTATIONS:
EFFECT OF BOLE SAMPLING INTENSITY AND EXPLANATORY VARIABLES
73
This me hod is based on he i o an appa en ly non ela ed equa ion sys em o med by he
eg ession unc ions o he biomass ac ions conside ed and he o al biomass. The SUR me hod
i e a i ely o ces he sum o he componen s o equal he equa ion o o al biomass, ensu ing ha
he global solu ion is he bes possible, al hough he solu ion o each k ac ion is no necessa ily
he bes . The independen a iables in he sys em o equa ions o biomass componen s has o be
he same as in he o al biomass equa ion (Pa esol, 2001), and in ac his equa ion was
exp essed as he sum o each componen equa ion o ensu e he addi i i y o he sys em (Ál a ez-
González e al., 2007). The MODEL p ocedu e o SAS was applied o ob ain he SUR es ima es,
conside ing he pa ame e s ob ained in he indi idual i ing as ini ialize s.
Lack o homogenei y in e o a iance, o he e oscedas ici y, is commonly obse ed in
biomass equa ions (Pa esol, 1993; 2001). As wi h he s anda d e o s o he pa ame e es ima es,
he e oscedas ici y was de ec ed by ep esen ing he s uden ized esiduals agains he eal alues,
and he Whi e (1980) and B eusch & Pagan (1979) es s we e applied. He e oscedas ici y was
co ec ed by weigh ed i ing (Schaegel, 1982; Clu e e al., 1983; Cunia, 1987; Pa esol, 1999;
2001), by use o he in e se o he a iance o he esiduals (σi2) assigned a each obse a ion as a
weigh ing ac o , and use o he po en ial exp ession [3.7] (Ne e e al., 1989).
k
i
2
ixσ [3.7]
The alue o he k exponen can be calcula ed by he op imiza ion me hod p oposed by Ha ey
(1976), which consis s o using he model e o s i ed wi hou weigh s ( i
e
ˆ) as dependen a iable
in he po en ial a iance e o model (Ál a ez-González e al., 2007), he linea ized o m o which is
shown in exp ession [3.8].
)k·ln(xa)e
ˆ
ln( i
2
i [3.8]
Fo each ac ion, he alue o he k exponen was de e mined o he independen a iables o
he combina ion o hese ha p o ided he bes i . In hose cases in which he s a is ics did no
de ec he e oscedas ici y, he weigh ed i was ca ied ou anyway. The alues o he k exponen s
we e added o he i ing p og am in SAS/STAT® (SAS Ins i u e Inc, 2004). A e i ing, he models
we e again subjec ed o he e oscedas ici y es s o e i y hei co ec ness.
3.3. Resul s
3.3.1. Es ima ion o bole biomass h ough sys ema ic subsamplig
The ela i e di e ence (RD) ob ained by he CW me hod was plo ed agains sys ema ic
subsampling in ensi y (disks m-1 o s em), o h ee dimensional classes: DC1 (d<14 cm), DC2
CHAPTER III
74
(14<d<24 cm) and DC3 (d>24 cm) (Fig. 3.3). The igu e shows o e es ima es o all he da a, wi h
a clea end o he ela i e e o o dec ease as sampling in ensi y inc eased. Small ees a e
clea ly biased owa ds o e es ima ion (d<14 cm), bu he endency o o e es ima ion dec eases
g ea ly wi h inc easing ee size. A h eshold o 5% ela i e e o would mean a minimum
subsampling in ensi y o 0.95 disks m-1 (DC1), 0.8 disks m-1 (DC2) o 0.75 disks m-1 (DC3). These
alues we e espec i ely 0.7, 0.4 and 0.3 disks m-1, o a ela i e e o h eshold se a 10%. I is
impo an o no e ha he de aul conside a ion o he s em bo om as he posi ion o he i s disk
would mean a sys ema ic endency o o e es ima ion.
Figu e 3.3. Rela i e di e ence o h ee dimensional classes: DC1 (d<14cm; n = 6 922), DC2 (14<d<24cm; n = 17075)
and DC3 (d>24cm; n = 18360), plo ed agains sampling in ensi y (disks pe s em me e ) o he CW me hod.
Con inuous black line: a e age alue o all da a; do ed black lines: 95% con idence in e als o all da a; con inuous
g ey line: a e age alue o al e na i es ha include bo om log. n is he numbe o simula ed al e na i es o each
dimensional class.
The RD alues ob ained o he PW me hod we e plo ed agains he subsampling in ensi y,
exp essed as he pe cen age o s em heigh ha was weighed (Fig. 3.4). Only he highe diame e
classes we e conside ed in his case, as he e is no eason o a oid ob aining he comple e esh
weigh o small ees. In his case he e was again a clea endency o he weigh s o be
o e es ima ed, which was e en clea e o he highes diame e class. This p ocedu e ensu ed a
maximum ela i e e o o 5%, only when 90% o he s em was weighed o bo h dimensional
classes conside ed. This pe cen age was 55% when he h eshold o ela i e e o was se a 10%.
IMPROVEMENT IN ACCURACY OF ABOVEGROUND BIOMASS ESTIMATION IN EUCALYPTUS NITENS PLANTATIONS:
EFFECT OF BOLE SAMPLING INTENSITY AND EXPLANATORY VARIABLES
75
In his case, conside a ion o he bo om log as he one ha should be weighed sys ema ically led
o unde es ima ion.
Figu e 3.4. Rela i e di e ence o wo dimensional classes: DC2 (14<d<24 cm; n = 7712) and DC3 (d>24cm; n =
12001), plo ed agains sampling in ensi y ( ac ion o s em heigh weighed) o he PW me hod. Con inuous black line:
a e age alue o all da a; do ed black lines: 95% con idence in e als o all da a; con inuous g ey line: a e age alue
o al e na i es ha include bo om log. n is he numbe o simula ed al e na i es o each dimensional class.
The di e ences in he wo me hods a ise om he obse ed ends in mois u e con en and
basic densi y along he s em. The mois u e con en (we basis) in ela ion o he ela i e heigh
along he s em indica es an inc easing end ha is mo e ma ked a he bo om 20%, whe e a ound
40% o bole d y ma e occu s (Fig. 3.5). The inc easing end o basic densi y (ρ, kg m-3) along he
s em, which can easily explain he unde es ima ions de i ed om he de aul use o he bo om log
in he PW me hod, is shown in Fig. 3.6.
0
10
20
30
40
50
60
0 102030405060708090100
Rela i e s em heigh (%)
Mois u e (%)
0
10
20
30
40
50
60
70
80
90
100
Acumula ed d y weigh (%)
Figu e 3.5. Changes in mois u e con en (%) and accumula ed s em d y weigh (%) plo ed agains ela i e heigh
along he s em (un il 7 cm o diame e o e ba k). Con inuous line: a e age alue; do ed lines: 95% con idence
in e als.
Such inc easing ends, which ha e been desc ibed o di e en species o eucalyp s, wi h
some excep ions, such as o Eucalyp us egnans, indica e he possibili y o s udying he ela i e
CHAPTER III
76
heigh a which he a e age basic densi y can be ound. This alue was plo ed o he sampled
ees wi h non-ze o amoun s o wood (Fig. 3.7). The ela i e heigh ended o dec ease wi h
inc easing b eas heigh diame e . These esul s a e o g ea in e es o de ining he heigh along
he s em ha should be sampled o ob ain a good es ima e o basic densi y.
0
100
200
300
400
500
600
700
800
900
1000
0 102030405060708090100
Rela i e s em heigh (%)
Basic densi y (Kg m
-3
)
0
10
20
30
40
50
60
70
80
90
100
Acumula ed esh olume (%)
Figu e 3.6. Changes in basic densi y (ρ, kg m-3) and accumula ed s em esh olume (%) plo ed agains ela i e s em
heigh (un il 7 cm o diame e o e ba k). Con inuous line: a e age alue; do ed lines: 95% con idence in e als.
Fo he PW me hod, i should be conside ed ha he e o s would be cumula i e i
ans o ma ion o esh weigh o he log o d y weigh is ca ied ou a e ob aining in o ma ion
de i ed om disks wi h equidis ance g ea e han 0.5 m. Mo eo e , he olumes we e calcula ed
conside ing 0.5 m logs, which could p o ide olume es ima es close o hose ob ained om wa e
displacemen o esh samples (B own e al., 1995).
0
5
10
15
20
25
30
35
40
45
50
0 5 10 15 20 25 30 35 40 45
d(cm)
Rela i e s em heigh (%) o a e age ρ
Figu e 3.7. Changes in ela i e s em heigh (%) whe e composi e a e age basic densi y (ρ) is ound in ela ion o
b eas heigh diame e o sampled ees. Con inuous line: a e age alue; do ed lines: 95% con idence in e als.
IMPROVEMENT IN ACCURACY OF ABOVEGROUND BIOMASS ESTIMATION IN EUCALYPTUS NITENS PLANTATIONS:
EFFECT OF BOLE SAMPLING INTENSITY AND EXPLANATORY VARIABLES
83
pe cen ages shown o diame e s less han 12 cm. As a esul , he equa ions p esen ed he e
would p o ide easonable es ima es o biomass componen pe cen ages o diame e s la ge han
12 cm. Fo smalle diame e s, exclusi e use o he equa ion p edic ing o al biomass is
ecommended.
0
10
20
30
40
50
60
70
80
90
0 10203040
d (cm)
P opo ion o abo eg ound biomass (%)
Ww
WTb
P ed. Ww
P ed, WTb
0
2
4
6
8
10
12
14
16
0 10203040
d (cm)
P opo ion o abo eg ound biomass (%)
Wdb
W b
P ed. Wdb
P ed. W b
0
5
10
15
20
25
010203040
d (cm)
P opo ion o abo eg ound biomass (%)
Wb
P ed. Wb
0
5
10
15
20
25
30
35
40
45
0 10203040
d (cm)
P opo ion o abo eg ound biomass (%)
Wl
W
P ed. Wl
P ed. W
Figu e 3.11. P opo ion o each biomass ac ion o e o al abo eg ound biomass. Open igu es: ees used in
de eloping biomass equa ions; illed igu es: addi ional small ees; lines: p edic ion o biomass equa ions.
3.4. Discussion
3.4.1. S em biomass es ima ion
The esul s o his s udy show ha he e o may be impo an , and will depend on he in ensi y
o subsampling, when a io- ype es ima o s a e used o es ima e d y mass. The e o also depends
on he me hod used (comple e esh weigh o pa ial esh weigh ) and on he a e age ee size.
O he au ho s ha e obse ed ha a io- ype es ima o s p o ide biased es ima es (Cunia, 1979;
Valen ine e al., 1984; B iggs e al., 1987). These o e es ima es a e as la ge as he dec eases in
bo h subsampling in ensi y and a e age ee size. O e es ima ion is clea ly a mo e se ious e o
han unde es ima ion (Sa oo & Madgwick, 1982) because i does no e on he side o sa e y i.e.
o ca bon accoun ing p ocedu es.

CHAPTER III
84
Wood mois u e con en and basic densi y change along he s em (Sa oo & Madgwick, 1982)
(Figs. 3.5 and 3.6), and a ec he es ima ion o d y biomass by he CW and PW me hods
espec i ely. Minimum mois u e con en and basic densi y occu in he basal pa o he s em,
which is ob iously whe e mos o he accumula ed weigh and olume occu . This e ec mus
he e o e be aken in o accoun wi h a su icien and well dis ibu ed numbe o subsamples along
he s em. One way o add essing his p oblem, when ape unc ions a e a ailable, is he densi y
in eg al app oach (Pa esol & Thomas, 1989). The weighed a e age is an al e na i e me hod ha
gi es mo e impo ance o hose obse a ions in he lowe pa o he s em, and he e o e mo e
closely ela ed o olume.
Cha e e al. (2001) epo ed ha he biomass alues o he smalles ees s ongly a ec he
alues o he model pa ame e s in he allome ic ela ion. This e ec is e en s onge when a
weigh ed adjus men me hodology is used, because he smalles ees, which a e less a iable, a e
mo e impo an han he la ges ees because o he e oscedas ici y co ec ion. I is he e o e
ad isable o ob ain he comple e d y weigh o he s em o small ees.
The deg ee o accu acy equi ed depends on he objec i e o he es ima ion, al hough
equilib ium be ween sampling in ensi y and he le el o p ecision mus be ensu ed (B own e al.,
1995). I a io- ype es ima o s a e chosen o s em d y biomass es ima ion, a ela i ely in ensi e
subsampling scheme should be implemen ed, as o he s au ho s indica ed o bo h a io- ype and
densi y-in eg al me hods (Pa esol, 1999). Compa ing he me hods conside ed he e, he CW
me hod p oduced be e esul s o he la ges dimensional class han he PW me hod (Figs. 3.3
and 3.4). This is because, o a gi en leng h o cubed and weighed pa , he p opo ion o e o al
s em (as an indica o o sampling in ensi y) di e s depending on ee size, and he e o e becomes
less impo an as ee size inc eases. This mus be aken in o accoun because he PW me hod is
usually used o la ge ees in which comple e weighing is ime-consuming.
The esul s clea ly show he ends in ela i e e o s de i ed om a de aul conside a ion o he
bo om disk o he bo om log as he i s sec ion o measu e. I is ad isable, i sys ema ic sampling
is o be used, o es ablish he subsampling in ensi y be o e andomizing he posi ion along he
s em o he i s disk o log o be measu ed. In he case o he PW me hod i is no ecommended
o ake only one sample log pe ee, al hough his was he app oach used in his s udy. The
subsampling in ensi y should be spli along he s em, and a good ep esen a ion o he bole a ea
whe e a e age basic densi y is likely o be ound is ad isable. Mos published pape s do no
p o ide in o ma ion abou he p opo ion o weighed and cubed logs o hei dis ibu ion along he
s em, al hough he mos easonable dis ibu ion would be sys ema ic o andom, wi h he
subsampling in ensi y chosen on he basis o s a is ical c i e ia.
3.4.2. Biomass equa ions om s em and c own a iables
Al hough i is known ha d, h and W a e closely ela ed (Sa oo & Madgwick, 1982), h is no
always included in biomass equa ions oge he wi h d because bo h a e co ela ed and inclusion o
IMPROVEMENT IN ACCURACY OF ABOVEGROUND BIOMASS ESTIMATION IN EUCALYPTUS NITENS PLANTATIONS:
EFFECT OF BOLE SAMPLING INTENSITY AND EXPLANATORY VARIABLES
85
h adds only negligible accu acy (Jokela e al., 1986; Te -Mikaelian & Ko zukhin, 1997; Johansson,
1999; Ve wijs & Telenius, 1999; Snowdon e al., 2000; B own, 2002; Po é e al., 2002; Jenkins e
al., 2003). In his s udy, inclusion o h oge he wi h d only esul ed in imp o ed accu acy in he
case o wood, al hough o he au ho s ha e epo ed signi ican imp o emen o se e al ac ions
(Loomis e al., 1966; Pea son e al., 1984; Ba elink, 1996; Reed & Tomé, 1998; Monse ud &
Ma shall, 1999). In hei s udy on Eucalyp us globulus, An ónio e al. (2007) obse ed
imp o emen s in he sum o esidual squa es o 72%, 8%, 12% and 10% o wood, ba k, lea es
and b anches espec i ely, a e inclusion o h oge he wi h d. I is possible ha in he p esen
s udy he ee sample was no ep esen a i e o he en i e a iabili y in heigh o a gi en diame e .
Some s udies included h and d in biomass models, oge he wi h densi y, age and si e index
(Te -Mikaelian & Pa ke , 2000; An ónio e al., 2007), and hese models a e he e o e sui able o
compa ing di e en si es (Ke e ings e al., 2001). O he s udies included age as an independen
a iable in biomass equa ions (Po é e al., 2002; Sain -And é e al., 2005), hus p oducing
dynamic models wi h which biomass inc emen s can be es ima ed by de i a i e analysis. Al hough
indi idually ds wo ked well as a p edic o , i is seldom measu ed in o es in en o ies. On he o he
hand, i is some imes use ul o es ima e d y biomass when ees a e al eady cu down and only
s ump dimensions a e a ailable.
I has been obse ed ha some c own a iables wo k well as p edic o s o c own ac ions
(Cla k, 1982; Sa oo & Madgwick, 1982; Ca alho & Pa esol, 2003). In he p esen s udy, inclusion
o c own a iables imp o ed he RMSE by 1.8%, 10.8%, 19.1% and 17.3% o espec i ely dead
b anches, hick b anches, wigs and lea es, in he indi idual i . These imp o emen s a e smalle
han hose ob ained by An ónio e al. (2007) o Eucalyp us globulus in Po ugal, p obably because
o he lowe gene ic a iabili y in he plan a ions conside ed in ou s udy. The bes imp o emen
was o lea es, which implies be e es ima ions o a ac ion ha is e y di icul o p edic and is
e y impo an as ega ds nu i ion and ecology. O e all, he esul s indica e a low accu acy o
es ima ion o he ba k ac ion in he p esen s udy, in compa ison wi h epo s o o he species o
Eucalyp us. Wood, ba k and hin b anches depend on he same a iables in bo h sys ems o
equa ions, and he esul s ob ained by simul aneous i ing we e gene ally only sligh ly less
accu a e. Fo lea es, he educ ion in R2Adj. de i ed om simul aneous i ing was 6.3%.
The abili y o he i ed biomass equa ions o e alua e he p opo ion o each abo eg ound
biomass componen o a ange o diame e s has seldom been s udied. The p opo ions a e o en
conside ed as pa ame e s o ecophysiological models, pa icula ly o small diame e s (Sands &
Landsbe g, 2002). The p esen esul s show ha , i a h eshold diame e is conside ed o de ining
a wood componen , minimum b eas heigh diame e mus be conside ed o de ine he ange o
use o he biomass componen s equa ions, i sound es ima ion o hese pe cen ages is sough .
CHAPTER III
86
3.5. Conclusions
Two sys ems o equa ions we e i ed o abo eg ound biomass componen s o Eucalyp us
ni ens. The inclusion o c own a iables as p edic i e a iables p o ided poo e esul s o o al
biomass, wood and hin b anches, bu imp o ed he accu acy o es ima ion o wigs, lea es, hick
b anches and dead b anches.
S em subsampling a ec s es ima ion o he wood ac ion. I a sys ema ic subsample o disks
o logs is aken, he a ia ion in mois u e con en o basic densi y along he s em should be
conside ed. Less in ensi e sampling usually leads o o e es ima ion o biomass wi h bo h me hods
(comple e esh weighing o pa ial esh weighing). The minimum subsampling in ensi y o an
assumed ±5% RD in wood d y biomass es ima ion depends on he ee diame e class, wi h a
ange o 0.75 o 0.95 disks m-1 in he CW me hod. Use o he PW me hod would equi e e y
in ense subsampling o educe he ela i e e o , independen ly o ee size. The a e age basic
densi y usually occu s a a ela i e heigh o 30-35% along he s em. I is no always ad isable o
choose he i s sec ion o s udy a he bo om o he s em.
3.6. Bibliog aphy
Ál a ez-González, J.G.; Rod íguez-Soallei o, R. & Rojo-Albo eca, A. 2007. Resolución de
p oblemas del ajus e simul áneo de sis emas de ecuaciones: he e ocedas icidad y a iables
dependien es con dis in o núme o de obse aciones. En: (Ja andilla de la Ve a (Cáce es)).
Mayo, .
An ónio, N.; Tomé, M.; Tomé, J.; Soa es, P. & Fon es, L. 2007. E ec o ee, s and, and si e
a iables on he allome y o Eucalyp us globulus ee biomass. Canadian Jou nal o Fo es
Resea ch. 37 (5): 895-906.
Ba elink, H.H. 1996. Allome ic ela ionships on biomass and needle a ea o Douglas- i . Fo es
Ecology and Managemen . 86 (1-3): 193-203.
B eusch, T.S. & Pagan, A.R. 1979. A simple es o he e oscedas ici y and andom coe icien
a ia ion. Econome ica. 47 (5): 1287-1294.
B iggs, R.D.; Cunia, T.; Whi e, E.H. & Yawney, H.W. 1987. Es ima ing sample ee biomass by
subsampling: some empi ical esul s. Es ima ing T ee Biomass Reg essions and Thei
E o .P oceedings o he Wo kshop on T ee Biomass Reg ession Func ions and hei
Con ibu ion o he E o o Fo es In en o y Es ima es.Compiled by EH Wha on and
T.Cunia.USDA Fo .Se .Gen.Tech.Rep.NE-117. : 119-127.
B oad, L.R. 1998. Allome y and G ow h. Fo es Science. 44: 458-464.
B own, I.F.; Ma inelli, L.A.; Thomas, W.W.; Mo ei a, M.Z.; Fe ei a, C.A.C. & Vic o ia, R.A. 1995.
Unce ain y in he biomass o Amazonian o es s: an example om Rondônia, B azil. Fo es
Ecology and Managemen . 75 (1-3): 175-189.
B own, S. 2002. Measu ing ca bon in o es s: cu en s a us and u u e challenges. En i onmen al
Pollu ion. 116 (3): 363-372.
Ca alho, J.P. & Pa esol, B.R. 2003. Addi i i y in ee biomass componen s o Py enean oak
(Que cus py enaica Willd.). Fo es Ecology and Managemen . 179 (1-3): 269-276.
IMPROVEMENT IN ACCURACY OF ABOVEGROUND BIOMASS ESTIMATION IN EUCALYPTUS NITENS PLANTATIONS:
EFFECT OF BOLE SAMPLING INTENSITY AND EXPLANATORY VARIABLES
87
Cha e, J.; Rié a, B. & Dubois, M.A. 2001. Es ima ion o biomass in a neo opical o es o F ench
Guiana: spa ial and empo al a iabili y. Jou nal o T opical Ecology. 17 (01): 79-96.
Cla k, A. 1982. P edic ing biomass p oduc ion in he Sou h. En: P edic ing G ow h and Yield in he
Mid-Sou h 119-139 pp.
Clu e , J.L.; Fo son, J.C.; Pienaa , L.V.; B is e , H.G. & Bailey, R.L. 1983. Timbe managemen : a
quan i a i e app oach John Wiley and Sons, New Yo k. 333 pp.
Cunia, T. 1987. Cons uc ion o ee biomass ables by linea eg ession echniques. En:
Es ima ing T ee Biomass Reg essions and hei E o : P oceedings o he Wo kshop on T ee
Biomass Reg ession Funk ions and hei Con ibu ion o he E o o Fo es In en o y
Es ima es 27-36 pp.
Cunia, T. 1979. On sampling ees o biomass ables cons uc ion: some s a is ical commen s. En:
Fo es esou ce in en o ies, Vol. 2. Ed. W.E. F aye , Colo ado S a e Uni e si y, Fo Collins,
Colo ado. 643-664 pp.
G egoi e, T.G.; Valen ine, H.T. & Fu ni al, G.M. 1995. Sampling me hods o es ima e oliage and
o he cha ac e is ics o indi idual ees. Ecology. 76 (4): 1181-1194.
Ha ey, A.C. 1976. Es ima ing Reg ession Models wi h Mul iplica i e He e oscedas ici y.
Econome ica. 44 (3): 461-465.
Jenkins, J.C.; Chojnacky, D.C.; Hea h, L.S. & Bi dsey, R.A. 2003. Na ional-Scale Biomass
Es ima o s o Uni ed S a es T ee Species. Fo es Science. 49 (1): 13-35.
Johansson, T. 1999. Biomass equa ions o de e mining ac ions o pendula and pubescen
bi ches g owing on abandoned a mland and some p ac ical implica ions. Biomass and
Bioene gy. 16 (3): 223-238.
Jokela, E.J.; Van G up, K.P.; B iggs, R.D. & Whi e, E.H. 1986. Biomass es ima ion equa ions o
no way sp uce in New Yo k. Canadian Jou nal o Fo es Resea ch. 16 (2): 413-415.
Ke e ings, Q.M.; Coe, R.; an Noo dwijk, M.; Ambagau, Y. & Palm, C.A. 2001. Reducing
unce ain y in he use o allome ic biomass equa ions o p edic ing abo e-g ound ee
biomass in mixed seconda y o es s. Fo es Ecology and Managemen . 146 (1-3): 199-209.
Kleinn, C. & Pelz, D.R. 1987. Subsampling ees o biomass. En: Es ima ing T ee Biomass
Reg essions and hei E o : P oceedings o he Wo kshop on ee Biomass Reg ession
Func ions and hei Con ibu ion o he E o o Fo es In en o y Es ima es. Eds. E.H. Wha on
& T. Cunia, Gen.Tech.Rep. NE-117 Edn., USDA Fo es Se ice, B oomall, PA: U.S. 225-227
pp.
Loomis, R.M.; Pha es, R.E. & C osby, J.S. 1966. Es ima ing oliage and b anchwood quan i ies in
sho lea pine. Fo es Science. 12 (1): 30-39.
Ma ínez Co izas, A. & Pé ez Albe i, A. 1999. A las Climá ico de Galicia Xun a de Galicia,
San iago de Compos ela. 207 pp.
Monse ud, R.A. & Ma shall, J.D. 1999. Allome ic c own ela ions in h ee no he n Idaho coni e
species. Canadian Jou nal o Fo es Resea ch. 29 (5): 521-535.
Ne e , J.; Wasse man, W.; Ku ne , M.H. & William Wasse man, M.H.K. 1989. Applied linea
eg ession models I win Homewood, Ill, New Yo k.
Pa esol, B.R. 2001. Addi i i y o nonlinea biomass equa ions. Canadian Jou nal o Fo es
Resea ch. 31 (5): 865-878.
Pa esol, B.R. 1999. Assessing T ee and S and Biomass: A Re iew wi h Examples and C i ical
Compa isons. Fo es Science. 45: 573-593.
Pa esol, B.R. 1993. Modeling mul iplica i e e o a iance: an example p edic ing ee diame e
om s ump dimensions in baldcyp ess. Fo es Science. 39 (4): 670-679.
Pa esol, B.R. & Thomas, C.E. 1989. A densi y-in eg al app oach o es ima ing s em biomass.
Fo es Ecology and Managemen . 26 (4): 285-297.
CHAPTER III
88
Pea son, J.A.; Fahey, T.J. & Knigh , D.H. 1984. Biomass and lea a ea in con as ing lodgepole
pine o es s. Canadian Jou nal o Fo es Resea ch. 14 (6): 259-265.
Pé ez-C uzado, C. 2009. He amien as de ges ión pa a plan aciones de Eucalyp us ni ens (Deane
& Maiden) Maiden con el obje i o de ijación de ca bono. T abajo de In es igación Tu elado.
Escuela Poli écnica Supe io de Lugo, Uni e sidad de San iago de Compos ela. 77 pp.
Po é, A.; T iche , P.; Be , D. & Lous au, D. 2002. Allome ic ela ionships o b anch and ee
woody biomass o Ma i ime pine (Pinus pinas e Ai .). Fo es Ecology and Managemen . 158
(1-3): 71-83.
Reed, D. & Tomé, M. 1998. To al abo eg ound biomass and ne d y ma e accumula ion by plan
componen in young Eucalyp us globulus in esponse o i iga ion. Fo es Ecology and
Managemen . 103 (1): 21-32.
Sain -And é, L.; M'Bou, A.T.; Mabiala, A.; Mou ondy, W.; Jou dan, C.; Roupsa d, O.; Delepo e,
P.; Hamel, O. & Nou ellon, Y. 2005. Age- ela ed equa ions o abo e-and below-g ound
biomass o a Eucalyp us hyb id in Congo. Fo es Ecology and Managemen . 205 (1-3): 199-
214.
Sands, P.J. & Landsbe g, J.J. 2002. Pa ame e isa ion o 3-PG o plan a ion g own Eucalyp us
globulus. Fo es Ecology and Managemen . 163 (1-3): 273-292.
SAS Ins i u e Inc 2004. SAS/STAT 9.1 Use 's Guide Ca y, N.C.
Sa oo, T. & Madgwick, H.A.I. (eds) 1982. Fo es Biomass, JSTOR, The Ne he lands.
Schaegel, B.E. 1982. Boxelde (Ace Negundo L.) Biomass Componen Reg ession Analysis o
he Mississippi Del a. Fo es Science. 20 (4): 617-628.
Snowdon, P.; Eamus, D.; Gibbons, P.; Khanna, P.K.; Kei h, H.; Raison, R.J. & Ki schbaum, M.U.F.
2000. Syn hesis o allome ics, e iew o oo biomass and design o u u e woody biomass
sampling s a egies. NCAS Technical Repo Edn., Aus alian G eenhouse O ice, Canbe a.
114 pp.
Te -Mikaelian, M.T. & Ko zukhin, M.D. 1997. Biomass equa ions o six y- i e No h Ame ican ee
species. Fo es Ecology and Managemen . 97 (1): 1-24.
Te -Mikaelian, M.T. & Pa ke , W.C. 2000. Es ima ing biomass o whi e sp uce seedlings wi h
e ical pho o image y. New Fo es s. 20 (2): 145-162.
Valen ine, H.T.; T i on, L.M. & Fu ni al, G.M. 1984. Subsampling ees o biomass, olume, o
mine al con en . Fo es Science. 30 (3): 673-681.
Ve wijs , T. & Telenius, B. 1999. Biomass es ima ion p ocedu es in sho o a ion o es y. Fo es
Ecology and Managemen . 121 (1-2): 137-146.
Whi e, H. 1980. A he e ocedas ici y-consis en co a iance ma ix es ima o and a di ec es o
he e ocedas ici y. Econome ica. 48 (4): 817-838.
Zianis, D. & Mencuccini, M. 2004. On simpli ying allome ic analyses o o es biomass. Fo es
Ecology and Managemen . 187 (2-3): 311-332.

89
Chap e IV
A managemen ool o es ima ing bioene gy p oduc ion and
ca bon seques a ion in Eucalyp us globulus and Eucalyp us
ni ens g own as sho o a ion woody c ops in no h-wes Spain
90
A MANAGEMENT TOOL FOR ESTIMATING BIOENERGY PRODUCTION AND CARBON SEQUESTRATION IN EUCALYPTUS GLOBULUS AND
EUCALYPTUS NITENS GROWN AS SHORT ROTATION WOODY CROPS IN NORTH-WEST SPAIN
91
4. A managemen ool o es ima ing bioene gy
p oduc ion and ca bon seques a ion in Eucalyp us
globulus and Eucalyp us ni ens g own as sho
o a ion woody c ops in no h-wes Spain
Abs ac
This s udy p oposes s and le el models o es ima ing biomass yield, o al ene gy and ca bon
seques a ion in Eucalyp us globulus and Eucalyp us ni ens plan a ions, on he basis o
measu emen s made in 131 plo s es ablished a he usual ange o ini ial o es densi ies o
sou hwes e n Eu ope. The imbe olume, o al abo eg ound biomass, logging esidue biomass,
c own biomass, ca bon in abo eg ound biomass and soil o ganic laye , ene gy in abo eg ound
biomass, ene gy in logging esidue biomass and usable cellulose yield we e ep esen ed in he
o m o isolines ( aking mo ali y in o accoun ) and plo ed agains dominan heigh . These
a iables we e calcula ed and compa ed wi h p e iously published da a on wo sil icul u al op ions
o sho o a ion o es y, one des ined o bioene gy p oduc ion and he o he consis ing o he
s anda d sil icul u e egime applied o bo h species in sou he n Eu ope, conside ing he a e age
si e index o each species. Yield le els we e highe in Eucalyp us ni ens han in Eucalyp us
globulus o all a iables because o as e diame e inc emen a simila densi ies. The o al yield
in e ms o biomass was 13.9-14.6 Mg ha-1 y -1 o Eucalyp us globulus and 20.4-21.5 Mg ha-1 y -1
o Eucalyp us ni ens. Ene gy in abo eg ound biomass anged be ween 233 and 245 GJ ha-1 y -1
o Eucalyp us globulus and 345 and 364 GJ ha-1 y -1 o Eucalyp us ni ens, ca bon accumula ion
a e in abo eg ound biomass and soil o ganic laye was 6.9-7.2 Mg ha-1 y -1 o Eucalyp us
globulus and 12.7-13.5 Mg ha-1 y -1 o Eucalyp us ni ens, and usable cellulose was 5.7-5.9 Mg
ha-1 y -1 o Eucalyp us globulus and 9.0-10.1 Mg ha-1 y -1 o Eucalyp us ni ens. I was ound ha
50% inc emen s in he ini ial densi y esul in only ma ginal inc emen s in biomass and usable
cellulose yields.
Keywo ds: sho o a ion o es y, eucalyp s, woody c ops, densi y managemen diag ams,
bioene gy p oduc ion, ca bon seques a ion.
4.1. In oduc ion
Sho o a ion woody c ops (SRWCs) (g own in sho o a ion o es y: SRF) a e an impo an
po en ial sou ce o cellulosic biomass, which can be used as solid uel in he o m o wood chips,
CHAPTER IV
92
pelle s o cha coal, ans o med in o e hanol ia a cellulosic pla o m and/o used in py olysis o
gene a e syngas and o he p oduc s (Johnson e al., 2007). The es ablishmen o single s em
s ands and subsequen eplan ing o coppicing is he mos common managemen egime in SRF,
and decisions abou eplan ing and coppicing should conside : (i) he yields om bo h op ions (ii)
es ablishmen cos s, and (iii) desi ed dimensions o he inal p oduc (Rockwood e al., 2006).
The genus Eucalyp us has been used in o es a ion in Eu ope since he ea ly 19 h cen u y
because o i s high p oduc i i y and plas ici y. The o al a ea cu en ly occupied by Eucalyp us
plan a ions in sou he n Eu ope is app oxima ely 14000 km2, wi h Eucalyp us globulus being he
mos common species bu wi h an inc easing p opo ion o Eucalyp us ni ens, which is g own
success ully as a os - ole an species. Bo h species belong o he subgenus Symphyomy us,
known o p oduce la ge a e age ee sizes and o be mo e p oduc i e han species o he
subgenus Monocalyp us (Da idson & Reid, 1980; Tu nbull e al., 1993; Sims e al., 1999a). The
managemen objec i e o hese plan a ions in sou he n Eu ope is cu en ly he p oduc ion o wood
pulp o ib eboa d, al hough logging esidues and he ba k de i ed om he ha es ing ope a ions
a e inc easingly used as bio uel o p oduce he mal ene gy and elec ici y.
The ideal cha ac e is ics o an ene gy c op a e: (i) high yield, (ii) low ene gy inpu o
p oduc ion, (iii) low cos , (i ) minimal con en s o con aminan s and ( ) low nu ien equi emen s
(McKend y, 2002). In his sense, Eucalyp us species adap well o ene gy p oduc ion, because o
he high yield and low wa e and nu ien equi emen s han o popla s and willows (Johnson e al.,
2007); Eucalyp us species accoun ed o 38% o o al SRF plan a ions h oughou he wo ld in
2003 (FAO, 2003). Be o e es ablishmen o a plan a ion i is impo an o conside he desi ed
combina ion o s em densi y and o a ion. Fo species ha mus be es ablished om seedlings, he
applica ion o na ow in e - and in a- ow spacing would lead o e y high cos s and low a ios o
wood/o he biomass componen s, wood/ba k o pe cen age o cellulose. Mo eo e , he a e age
size o ee dec eases as N inc eases (Bulla d e al., 2002) and la ge logs a e mo e dense.
Nu ien deple ion is also less likely o longe o a ions, which also p o ide p oduc lexibili y
(E icsson, 1994; Guo e al., 2002). Eucalyp s in sou he n Eu ope es ablished a ini ial densi ies o
1000 o 2400 s ems pe ha can he e o e supply he bioene gy indus y as he main plan a ion
objec i e o h ough he use o logging esidues o ene ge ic pu poses.
Fo es plan a ions de elop om a collec ion o indi idual, eely g owing ees, h ough he
onse o compe i ion, o ull si e occupancy and sel - hinning. S and de elopmen is commonly
displayed as a ajec o y o inc easing mean ee size wi h dec easing s and densi y (Long e al.,
2004). Dynamic s and densi y managemen diag ams (SDMDs) illus a e he ela ionships among
yield, densi y and densi y-dependen mo ali y a all s ages o s and de elopmen . Thei use has
been p o en o be an e ec i e me hod o he design, display and e alua ion o al e na i e densi y
managemen egimes in he ield o e en-aged o es y (New on, 1997). The adap a ion o such
managemen ools o he ield o sho o a ion o es y o bioene gy p oduc ion may assis in he
assessmen o ene gy yield po en ial, op imum s and managemen in e ms o densi y and o a ion
in compa ison wi h o he po en ially use ul woody species.
A MANAGEMENT TOOL FOR ESTIMATING BIOENERGY PRODUCTION AND CARBON SEQUESTRATION IN EUCALYPTUS GLOBULUS AND
EUCALYPTUS NITENS GROWN AS SHORT ROTATION WOODY CROPS IN NORTH-WEST SPAIN
99
agains s and densi y o de e mine he maximum a e age c own biomass a 1000 s ems ha-1
(Wc1000, kg ee-1). The FDC equa ion was hen de i ed om equa ion [4.14] by subs i u ing K o
2
3
1000 1000
c
W.
Al hough he -3/2 powe law o sel - hinning (Yoda e al. 1963) is assumed o be alid o all
species and loca ions, some ac o s such as se e e nu ien de iciencies (Lonsdale & Wa kinson,
1982; Mo is & Mye scough, 1991), clima ic condi ions and a i icial shading (Aikman & Wa kinson,
1980) may a ec he ajec o y o FDC. This implies ha i is mo e app op ia e o de ine a ull
densi y zone (FDZ), in which he p obabili y o mo ali y due o he sel - hinning e ec is e y high
(Jack & Long, 1996). The lowes bounda y limi o FDZ was de e mined as 70% o Wc1000 (DeBell &
Whi esell, 1988). Bo h limi s o FDZ we e ep esen ed in he diag ams by sol ing equa ion [4.14]
o N.
Mechanized ha es ing implies a size limi a ion due o he machine y used. Isolines o 10 and
20 cm o a e age s ump diame e ( s
d, cm) we e he e o e ep esen ed in he diag ams. Fo his, a
linea ela ionship be ween dg and d was i ed o bo h species. s
d can be es ima ed accu a ely
om he a e age diame e a b eas heigh by use o a linea model (Diéguez-A anda e al., 2003).
The model de eloped by Sánchez e al. (2004) was used o es ima e E. globulus s
d, and a simila
model, de eloped wi h da a collec ed in he plo s es ablished in he p esen s udy, was used o
es ima e E. ni ens s
d.
4.3. Resul s
4.3.1. Model pa ame e s and addi ional ela ions
Resul s o he non-linea i o equa ions [4.2-4.10], he coe icien es ima es and he
eg ession s a is ic alues a e shown in Table 4.3. All coe icien s we e signi ican a p<0.05, and
he models accoun ed o mo e han 84% o he o al a iabili y in he quad a ic mean diame e ,
and mo e han 94% o he o al a iabili y in p oduc i i y, equa ions [4.3-4.10].
As expec ed, he leas accu a e models we e hose p edic ing dg, since he app oach used in
de eloping his ype o diag am is o p edic yield a he han inc emen , which makes hem o li le
use, ela i e o dynamic g ow h models, o simula ing a b oad ange o sil icul u al egimes
(Ga cía, 1994). Wi h ega d o he p oduc i i y equa ions, he C model was he leas accu a e,
because he ca bon in he soil o ganic laye is ba ely ela ed o he independen a iables
conside ed, and is mo e closely ela ed o ime since las pe u ba ion. The changes in o al ca bon
in he abo eg ound biomass and in he soil o ganic laye o e ime a e shown in Fig. 4.2.

CHAPTER IV
100
Table 4.3. Non-linea eg ession coe icien s and s a is ics ob ained om simul aneous i ing o he sys em o 10
equa ions p edic ing quad a ic mean diame e (dg, cm), s and olume (V, m3 ha-1), o al ae ial biomass (W, Mg ha-1),
c own biomass (Wc, Mg ha-1), o al ca bon in abo eg ound biomass and soil o ganic laye (C, Mg ha-1), logging
esidue biomass (Ww, Mg ha-1), o al ae ial ene gy wi hou lea es (E, TJ ha-1), logging esidue ene gy (Ew, TJ ha-1),
usable cellulose p oduc ion (UC, Mg ha-1).
Equa ion Eucalyp us globulus Pa ame e es ima es Adjus ed R2
RMSE
[4.2] b0=16.37744
(9.7711)
b1=-0.38706
(0.0699)
b2=0,.868226
(0.0858) 0.8480 3.1225
[4.3] b3=0.000064
(0.000018)
b4=2.047556
(0.0504)
b5=0.756605
(0.0482)
b6=0.981972
(0.0235) 0.9950 17.8455
[4.4] b7= 0.000034
(5.775E-6)
b8=2.132935
(0.0164)
b9=0.732106
(0.0175)
b10=0.97052
(0.0133) 0.9984 6.0913
[4.5] b11=0.000012
(1.79E-6)
b12=2.457291
(0.0145)
b13=0.077533
(0.0148)
b14=1.036985
(0.0134) 0.9987 0.8934
[4.6] b15=0,.000021
(2.023E-6)
b16=2.259985
(0.00986)
b17=0.03626
(0.0109)
b18=1.014372
(0.00884) 0.9992 0.4474
[4.7] b19=0.000073
(0.000029) b20=2.058496
(0.0528) b21=0.512052
(0.0602) b22=0.899273
(0.0426) 0.9911 6.9936
[4.8] b23=5.544E-7
(9.644E-8)
b24=2.130056
(0.0168)
b25=0.745888
(0.0179)
b26=0.969512
(0.0136) 0.9984 0.1043
[4.9] b27=1.888E-7
(2.813E-8)
b28=2.459492
(0.0146)
b29=0.07792
(0.0149)
b30=1.037102
(0.0135) 0.9987 0.0142
[4.10] b31=0.00001
(2.413E-6)
b32=2.073132
(0.0228)
b33=0.918631
(0.0247)
b34=0.953745
(0.0180) 0.9974 3.3231
Equa ion Eucalyp us ni ens Pa ame e es ima es Adjus ed R2 RMSE
[4.2] b0=23.23792
(11.4785)
b1=-0.34626
(0.0586)
b2= 0.70549
(0.0728) 0.8437 3.0194
[4.3] b3=0.000068
(0.000017)
b4=1.936645
(0.0752)
b5=0.800026
(0.0628)
b6=1,005736
(0.0252) 0.9956 14.9311
[4.4] b7=0.000025
(2.157E-6)
b8=2.24867
(0.0140)
b9=0.665185
(0.0128)
b10=0.980934
(0.00781) 0.9987 4.2858
[4.5] b11=0.000026
(4.245E-6)
b12=2.353757
(0.0326)
b13=0.08703
(0.0265)
b14=0.991036
(0.0168) 0.9960 1.5209
[4.6] b15= 2.714E-6
(5.996E-7)
b16=2.756195
(0.0409)
b17=0.180144
(0.0308)
b18=1.002181
(0.0218) 0.9941 1.1395
[4.7] b19=0.000231
(1.97E-5) b20=1.902716
(0.1489) b21=0.485519
(0.1429) b22=0.834961
(0.1109) 0.9475 14.9173
[4.8] b23= 4.196E-7
(3.662E-8)
b24=2.24873
(0.0140)
b25=0.667739
(0.0128)
b26=0.980905
(0.00783) 0.9987 0.0734
[4.9] b27=4.219E-7
(7.089E-8)
b28=2.355724
(0.0341)
b29=0.089347
(0.0277)
b30=0.99033
(0.0175) 0.9957 0.0256
[4.10] b31=0.000016
(2.892E-6)
b32=1.844636
(0.0275)
b33=0.93374
(0.0290)
b34=0.973451
(0.0137) 0.9956 3.4338
A MANAGEMENT TOOL FOR ESTIMATING BIOENERGY PRODUCTION AND CARBON SEQUESTRATION IN EUCALYPTUS GLOBULUS AND
EUCALYPTUS NITENS GROWN AS SHORT ROTATION WOODY CROPS IN NORTH-WEST SPAIN
101
Eucalyp us globulus
0
50
100
150
200
250
0 5 10 15 20 25
(yea s)
Ca bon (Mg ha
-1
)
Eucalyp us ni ens
0
50
100
150
200
250
0 5 10 15 20 25
(yea s)
Ca bon (Mg ha
-1
)
ABOVEGROUND BIOMASS
SOIL ORGANIC LAYER
Figu e 4.2. Ca bon accumula ion in abo eg ound biomass and soil o ganic laye o e ime (Mg ha-1) o Eucalyp us
globulus and Eucalyp us ni ens plan a ions.
The dynamics o accumula ion we e qui e di e en in bo h compa men s (Fig. 4.2), while he e
was a high a e o accumula ion o abo eg ound biomass ca bon in bo h species (al hough
dependen o si e quali y, Ca bon a 8.3 Mg ha-1 y -1 on a e age), he ca bon in he li e ends o
s abilize a 5-7 yea s in bo h species, and eaches alues o Ca bon a 10 and 25 Mg ha-1 a his
age in E. globulus and E. ni ens plan a ions.
The ela ion be ween he a e age c own biomass (kg ee-1) and he numbe o ees pe
hec a e o each plo and species, including se e al isolines o Wc1000 is shown in Fig. 4.3. I we
conside only he plo s wi h low IH alues and ha p obably unde go sel - hinning (Lonsdale,
1990), he mos easonable alues o he Wc1000 a e 60 kg ee-1 o E. globulus and 50 kg ee-1
o E. ni ens. This indica es ha E. ni ens ole a es lowe densi ies han E. globulus, which is
consis en wi h p e ious indings o his species (Sims e al., 1999a; Sims e al., 2001). These
alues a e equi alen o abo eg ound biomass o 360 kg ee-1 o E. globulus and 285 kg ee-1 o
E. ni ens, alues simila o he sel - hinning h eshold de ined o pa ame e ize he 3-PG model o
E. globulus in Aus alia (300 kg ee-1, Sands & Landsbe g, 2002).
Eucalyp us ni ens
45
50
55
60
65
70
0
20
40
60
80
100
120
400 600 800 1000 1200 1400 1600 1800 2000 2200
N
A e age c own biomass
Wc1000
Eucalyp us globulus
45
50
55
60
65
70
0
20
40
60
80
100
120
400 600 800 1000 1200 1400 1600 1800 2000
N
A e age c own biomass
Wc1000
Figu e 4.3. Rela ion be ween a e age c own biomass and numbe o s ems pe hec a e (N) o Eucalyp us globulus
and Eucalyp us ni ens plan a ions: de e mina ion o sel - hinning h eshold.
CHAPTER IV
102
The pa ame e alues o he linea models o des ima ion om dg o each species a e
shown in Table 4.4. The model accu acy was e y high o bo h species, allowing he inco po a ion
o he ha es ing limi s o s
do 10 and 20 cm.
Table 4.4. Equa ions o dg es ima ion om d o Eucalyp us globulus and Eucalyp us ni ens plan a ions.
Equa ion
Adjus ed R2 RMSE
Eucalyp us globulus 4067004051 .d.dg



0.9954 0.5474
Eucalyp us ni ens 344003221 .d.dg



0.9937 0.4365
4.3.2. S and Densi y Managemen Diag ams
The SDMDs ob ained o E. globulus and E. ni ens a e shown in Figs. 4.4-4.7. The isolines o
quad a ic mean diame e , ca bon in biomass and o ganic soil, Ha -Becking index and mo ali y, as
well as he posi ions o he sample plo s a e shown in Figs. 4.4 and 4.6. The isolines o usable
cellulose, abo eg ound biomass ene gy, ha es limi s and mo ali y a e shown in Figs. 4.5 and
4.7. Al hough SDMDs p o ide use ul g aphic in o ma ion abou s and de elopmen s ages, o
mo e accu a e es ima ion, equa ions [4.2-4.10] and he pa ame e s shown in Table 4.3 mus be
used.
As can be seen in he SDMD, dg dec eases o a gi en H0 as N inc eases because o
inc eased compe i ion o esou ces, which esul s in a smalle a e age ee size (Hamil on, 1969;
Assmann, 1970; Cu is, 1970; Dean & Long, 1992). The pa e n o dg isolines is pa allel o ha
obse ed o he ha es limi s, and hus a h eshold es ablished o basal diame e would mean
ha a combina ion o ini ial plan ing densi y and dominan heigh a ha es would ha e o be
conside ed.
Fo compa able s ages o s and de elopmen (in e ms o H0 and N), E. ni ens accumula es
mo e ca bon in biomass and soil o ganic laye , and his e ec is pa ly a ibu able o he highe
a e o accumula ion o C in soil o ganic laye (Figs. 4.4 and 4.6).
The shape o biomass- ela ed isolines (W, Ww, Wc, E and Ew) a e mo e e ical han he
olume- ela ed isolines (V and UC) (Figs. 4.5 and 4.7). This indica es ha biomass- ela ed isolines
a e less sensi i e o changes in N han olume ela ed isolines. Mo eo e , o compa able s ages
o s and de elopmen , E. ni ens has mo e ene gy in abo eg ound biomass and usable cellulose
han E. globulus, because o as e diame e g ow h a compa able le els o N and H0. These
esul s a e consis en wi h hose o o he s udies o single s em c ops o E. ni ens a 2200 ees
ha-1 (Sims e al., 1999a).
A MANAGEMENT TOOL FOR ESTIMATING BIOENERGY PRODUCTION AND CARBON SEQUESTRATION IN EUCALYPTUS GLOBULUS AND
EUCALYPTUS NITENS GROWN AS SHORT ROTATION WOODY CROPS IN NORTH-WEST SPAIN
103
6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42
DOMINANT HEIGHT (m)
DENSITY (s ems ha
-1
)
600
700
12
18
20
26
30
32
14
800
900
16
22
24
28
10
500
1400
1600
2400
1800
2000
1200
1000
400
2200
8
34
36
10
6
38
40
30
QUADRATIC MEAN DIAMETER (cm)
HART-BECKING
INDEX (%)
MORTALIT
Y
CARBON IN BIOMASS AND
ORGANIC SOIL (Mg·ha-1)
PLOTS
20
20 40 60 80 100 120 140 160
180
200
220
240
40
Figu e 4.4. S and Densi y Managemen Diag am o Eucalyp us globulus wi h isolines o : quad a ic mean diame e ,
ca bon in biomass and o ganic soil, Ha -Becking index, mo ali y and sample plo s.
6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42
DOMINANT HEIGHT (m)
DENSITY (s ems ha
-1
)
600
700
800
900
500
1400
1600
2400
1800
2000
1200
1000
400
2200
15 45 60 75 90 120 150 180 210
240
1,8 2,4 4,2
1,2
0,6 3 3,6 4,8 5,4 6
6,6
7,2
7,8
8,4
9
10 20
30
ABOVEGROUND BIOMASS
ENERGY (TJ·ha
-1
)
USABLE CELLULOSE (Mg·ha
-1
)
MORTALIT
Y
HARVEST LIMITS (cm)
Figu e 4.5. S and Densi y Managemen Diag am o Eucalyp us globulus wi h isolines o : usable cellulose,
abo eg ound biomass ene gy, ha es limi s and mo ali y.
CHAPTER IV
104
6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42
DOMINANT HEIGHT (m)
DENSITY (s ems ha
-1
)
600
700
12
18
20
26
30
32
14
800
900
16
22
24
28
10
500
1400
1600
2400
1800
2000
1200
1000
400
2200
8
34
36
10
20
3040
38
40
20 40 60 80 100 120 140 160 180
200
220
240
260
QUADRATIC MEAN DIAMETER (cm)
HART-BECKING INDEX (%)
MORTALIT
Y
CARBON IN BIOMASS AND
ORGANIC SOIL (Mg·ha
-1
)
PLOTS
Figu e 4.6. S and Densi y Managemen Diag am o Eucalyp us ni ens wi h isolines o : quad a ic mean diame e ,
ca bon in biomass and o ganic soil, Ha -Becking index, mo ali y and sample plo s.
6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42
DOMINANT HEIGHT (m)
DENSITY (s ems ha
-1
)
600
700
1,8
5,4
6
7,2
7,8
2,4
800
900
4,2
6,6
1,2
500
1400
1600
2400
1800
2000
1200
1000
400
2200
0,6
15 30 45 60 75 90 105 120 150
180
33,6 4,8
10 20
A
BOVEGROUND BIOMASS
ENERGY (TJ·ha
-1
)
USABLE CELLULOSE (Mg·ha
-1
)
MORTALIT
Y
HARVEST LIMITS (cm)
Figu e 4.7. S and Densi y Managemen Diag am o Eucalyp us ni ens wi h isolines o : usable cellulose, abo eg ound
biomass ene gy, ha es limi s and mo ali y.

A MANAGEMENT TOOL FOR ESTIMATING BIOENERGY PRODUCTION AND CARBON SEQUESTRATION IN EUCALYPTUS GLOBULUS AND
EUCALYPTUS NITENS GROWN AS SHORT ROTATION WOODY CROPS IN NORTH-WEST SPAIN
105
The changes in li e- ee densi ies a e shown in all he diag ams and allow es ima ion o
expec ed na u al mo ali y a e plan ing in a scena io o no hinning, which is gene ally applied o
woody c ops des ined o ene gy o ib e p oduc ion. I mus be conside ed ha hese ends we e
calcula ed by conside ing he a e age si e index o bo h species and hus a si e speci ic
calcula ion using equa ions [4.11] and [4.12] is ecommended i g ea e accu acy is sough . A high
plan a ion densi y, oge he wi h longe o a ions, esul s in high sel - hinning mo ali y and uns able
s ems, as al eady co obo a ed (Sims e al., 2001). As he ini ial densi y inc eases, he bounda y o
he FDZ is close in e ms o H0 and he e o e he managemen window is smalle . Al hough he
ela ionship be ween he numbe o ees pe hec a e and he a e age ee size is a good indica o
o densi y and he e o e o compe ence, he e a e o he ac o s ha a ec he sel - hinning
p ocess, such as ee dis ibu ion and accumula ion o gaps (Li e al., 2000), which is no impo an
when a egula squa e dis ibu ion is conside ed, bu could be in he case o pai ed ow layou s.
In he SDMD p oposed he e, se e al ha es ing limi s we e ep esen ed. The s
d10 cm limi
de ines he a ea in which a chip ha es e may be mo e p o i able. The s
d 10 and 20 cm limi s
de ine he a ea whe e a mul i-cu e ha es e may be mo e cos e ec i e, whe eas a e age basal
diame e s abo e s
d20 cm would limi he choice o adi ional single-s em ha es e s.
Since all models depend on N, he p oduc ion cos can be easily de e mined, and oge he wi h
a co ec es ima e o si e quali y, will de e mine he ime needed o ob ain he desi ed p oduc s and
he e o e he economic p o i abili y o he plan a ion.
4.3.3. P ac ical example o SDMD o de e mining ene gy p oduc ion
SDMDs can be used o es ima e p oduc ion om a gi en s and de elopmen s age (N and H0),
o o es ima e he minimum densi y ha can p o ide a ce ain ou pu o an a e age ee size. As a
p ac ical example, wo sil icul u al al e na i es we e simula ed o each species, wi h ini ial
densi ies o 2400 and 1600 s ems ha-1, ep esen a i e o an ene gy op ion and a s anda d
sou he n Eu opean pulp p oduc ion a ge , espec i ely. The o a ion ime (T) was de ined as he
ime ha allows e icien ha es ing o he c op by a mul i-cu e ha es e ( s
d 20 cm) in he case
o he ene gy a ge o an a e age si e index. Fo he s anda d pulp sil icul u e, s and g ow h was
simula ed un il one o he wo species eached he FDZ a ea, o which E. ni ens occu ed a a
dominan heigh o 29 m. The s and de elopmen s ages a he ime o ha es and o a ion ime o
he a e age si e index a e shown o bo h al e na i es and species (Table 4.5). The p edic ed dg a
he end o o a ion and yield alues o V, W, Ww, Wc, C, E, Ew and UC o he wo sil icul u al
al e na i es a e also shown.
The o al abo eg ound biomass yield o all ac ions anged be ween 13.9 and 14.6 Mg ha-1
y -1 o E. globulus and be ween 20.4 and 21.5 Mg ha-1 y -1 o E. ni ens (Table 4.5). The mean
annual inc emen in e ms o biomass was only ma ginally highe o he high densi y sil icul u e,
al hough he o a ion age was also sho e in his case. The alues o he expec ed yield in e ms
CHAPTER IV
106
o ene gy o usable cellulose we e highe o E. ni ens, al hough di ec compa ison is di icul , as
he species g ow in di e en a eas.
Table 4.5. P edic ed yield o he wo sil icul u al al e na i es conside ed.
N0=2400 N
0=1600
Eucalyp us globulus Eucalyp us ni ens Eucalyp us globulus Eucalyp us ni ens
N1 (s ems ha-1) 1700 2100 925 1300
H01 (m) 27.6 27.2 28.5 28.7
T (yea s) 14 11 15 12
dg (cm) 16.7 16.8 20.3 20.2
Yield uni s ha-1 ha-1 y -1 ha-1 ha-1 y -1 ha-1 ha-1 y -1 ha-1 ha-1 y -1
V (m3) 356.6 25.5 503.0 45.7 356.3 23.8 489.7 40.8
W (Mg) 204.1 14.6 236.3 21.5 208.2 13.9 244.6 20.4
Ww (Mg) 33.5 2.4 52.9 4.8 34.6 2.3 53.9 4.5
Wc (Mg) 24.8 1.8 25.5 2.3 24.9 1.7 28.0 2.3
C (Mg) 101.1 7.2 148.4 13.5 104.2 6.9 151.9 12.7
E (TJ) 3.430 0.245 4.000 0.364 3.501 0.233 4.141 0.345
Ew (TJ) 0.531 0.038 0.865 0.079 0.549 0.037 0.882 0.074
UC (Mg) 83.2 5.9 110.9 10.1 85.0 5.7 108.4 9.0
4.4. Discussion
4.4.1. Model pe o mance and limi a ions
The model p esen ed he e ep esen s a sys em o ela ed equa ions ha enable accu a e
es ima ion o c op yield in e ms o o en d y biomass, o al ene gy, usable cellulose and o he
a iables, and hus p o ides a powe ul ool o decision making as ega ds woody c ops o he
species s udied. The diag ams show he c op de elopmen as dominan heigh inc eases, and a e
he e o e independen o age and alid o applying o di e en b eeding ma e ials and si es o
each species, p o ided he change in dominan heigh wi h age is known in each case. These
empi ical s a is ically based ools can also be combined wi h p ocess-based models i he de ailed
in o ma ion equi ed in his case is a ailable.
Woody biomass can be con e ed ia combus ion, gasi ica ion, py olysis and e men a ion,
and he ene gy eco e ed depends on he con e sion echnology (McKend y, 2002). Al hough he
ene gy ob ained om LHV is a heo e ical alue ha can only be achie ed a 0% mois u e, he
in o ma ion ob ained om he diag ams, pa icula ly he sha e o logging esidues, and he
p opo ion o cellulose o s em olume, is use ul o de e mining he sui abili y o he biomass
p oduced o subsequen p ocessing.
A MANAGEMENT TOOL FOR ESTIMATING BIOENERGY PRODUCTION AND CARBON SEQUESTRATION IN EUCALYPTUS GLOBULUS AND
EUCALYPTUS NITENS GROWN AS SHORT ROTATION WOODY CROPS IN NORTH-WEST SPAIN
107
The models p o ided he e a e only alid o single s em o a ions, which is an impo an
cons ain o be conside ed. Howe e , his is no a key limi a ion in he case o E. ni ens, because
some s udies ha e shown he poo coppicing abili y o E. ni ens (Sims e al., 2001; Li le &
Ga dne , 2003), a leas o he b eeding ma e ials cu en ly in use. Changes in g ow h pa e ns
and ela ionships among s and a iables a e coppicing ha e been shown, pa icula ly he change
in basal a ea de i ed om he sp ou numbe pe s ool (Sims e al., 1999b). I is he e o e
necessa y o ob ain a simila model o E. globulus coppice s ands in o de o assess he long e m
p oduc i i y.
One o he main ad an ages o he models p o ided in his pape is he possibili y o assessing
he economic p o i abili y o SRC wi h eucalyp s, because many a iables a e needed o calcula e
he cash low h oughou he o a ion. Mos p oduc ion cos s, om es ablishmen o deli e y, can
be calcula ed as hey a e densi y-dependen , as is he case o plan a ion, localized e iliza ion and
weed con ol. Plan ma e ial may accoun o up o 65% o es ablishmen cos s and any ad an age
gained by high plan ing a es may be ou weighed by inc easing cos s (Mi chell e al., 1999). S and
ha es ing cos s cons i u e a majo po ion o o al p oduc ion cos s, and may ha e e ec s as
impo an as hose o s and es ablishmen cos s (Whi esell e al., 1992). Ha es ope a ions
ep esen up o 70% o he cos in he o e all supply chain, and he e o e less equen ha es ing
educes he cos o biomass p oduc ion pe uni (Mi chell e al., 1999). Mo eo e , a e age ee size
is he mos impo an ac o in ha es ing cos s (Whi esell e al., 1992). The in o ma ion p o ided in
he diag ams, pa icula ly he a e age basal diame e , is also essen ial o deciding wha ype o
ha es ing o ca y ou , i.e. whole s em ha es ing o chip ha es ing.
4.4.2. Ca bon seques a ion
The diag ams ob ained in his pape and he i ed equa ions cons i u e a powe ul ool o
assessing ca bon seques a ion in eucalyp s g own in SRF. The isolines plo ed in he diag ams
ange be ween 20 and 200 Mg ha-1 o ca bon in abo eg ound biomass and li e . Since no
in o ma ion was ob ained o oo biomass i was no possible o assess seques a ion in his
compa men , which is an impo an conside a ion because oo biomass is usually le in si u a e
he c op is ha es ed.
The alues o ca bon in li e show g ea e accumula ion o C in he li e esul ing om E.
ni ens han in E. globulus c ops. Ne p oduc ion in a o es should be assessed as he sum o
biomass accumula ion and annual li e p oduc ion, in which E. globulus plan a ions o densi y
4167 s ems ha-1 may each 13.4 Mg ha-1 y -1, and as much as 10-20% o he o al biomass
p oduc ion a age 3 yea s (Toky & Ramak ishnan, 1983). Al hough his li e can ha dly be used o
ene gy p oduc ion, es ima ion o he quan i y is impo an o es ima ing ca bon accumula ion and
nu ien cycle e u n. Al hough he soil mine al laye was no conside ed he e, ca bon accumula ion
in his pool is e y impo an because he li espan o he ca bon is longe han in biomass and in
he soil o ganic laye (Romanya e al., 2000).
CHAPTER IV
108
4.4.3. Compa ison o da a om o he s udies
The biomass yields (Table 4.5) a e highe han he 1-9 Mg ha-1 y -1 epo ed o 4-yea -old E.
globulus plan ed a a densi y o 2196 s ems ha-1 (C ome e al., 1975), bu lowe han he 24 Mg
ha-1 y -1 obse ed in 3-yea -old plan a ions o he same species in New Zealand, es ablished a a
densi y o 4167 s ems ha-1 and i iga ed wi h e luen . No i iga ed s ands yielded as much as 19.3
Mg ha-1 y -1 (Guo e al., 2002). E. globulus plan ed a densi ies o 20000, 30000 and 40000 s ems
ha-1 in Po ugal (Pe ei a e al., 1994) yielded 16, 21 and 19 Mg ha-1 y -1 a e 2 yea s. The gene al
e ec is he e o e a simila a e age yield (ob ained ea ly on because o he ini ial high s ocking
densi y) bu wi h a dec ease in he a e age ee size (Dickmann, 2006). Re e enced yield da a o
E. ni ens in SRF a e sca ce and alues a e e y low compa ed wi h hose obse ed in he p esen
s udy. Sims e al. (2001) epo ed 3-7.3 Mg ha-1 y -1 o single s ems es ablished a a densi y o
5000 s ems ha-1 and i s coppice o a ion, espec i ely, wi h e y low su i al. As ega ds o he
Eucalyp us species, Wise & Pi man (1981) collec ed yield da a o se e al Eucalyp us species in
Aus alia, and obse ed alues o be ween 11 and 16 Mg ha-1 y -1. Sachs e al. (1980) epo ed
Eucalyp us yields as high as 40 Mg ha-1 y -1 in a wide ange o si es. The a e age yield o
Eucalyp us species in a single s em o a ion a a densi y o 2200 ees ha-1 epo ed by Sims e al.
(1999a) anged be ween 9.6 and 15.5 Mg ha-1 y -1, which a e he highes epo ed alues o he
species, wi h high su i al a es and la ge a e age ee size. The alues obse ed he e we e
simila o highe and we e de e mined om comme cial sized plo s wi h conse a i e assump ions
o si e quali y.
Wi h ega d o ene gy p oduc ion a he end o o a ion, he p edic ed alues anged be ween
3.4-3.5 and 4.0-4.1 TJ ha-1 o E. globulus and E. ni ens espec i ely, well abo e he alues
epo ed o popla (173-259 GJ ha-1; 10-15 Mg ha-1 y -1) and willow (187-280 GJ ha-1; 10-15 Mg
ha-1 y -1) g own as sho o a ion woody c ops. Mean alues anged om 245 o 345 GJ ha-1 y -1,
s ill a om he a e age ange o eucalyp plan a ions in A ac uz (450 o 650 GJ ha-1 y -1,
(Mo ei a, 2006)). The annual logging esidue ene gy yield was 33-35 and 53-54 GJ ha-1 y -1 o
E. globulus and E. ni ens espec i ely, simila o he 65 GJ ha-1 y -1 es ima ed o bo h species
oge he , also in no he n Spain (Pé ez e al., 2008).
Ro a ions simula ed o he bioene gy al e na i e in his pape a e longe han he a e age
conside ed in SRC, bu he e a e posi i e e ec s o his p ac ice. I wood is he main biomass
compa men desi ed, longe o a ions p o ide highe wood:ba k a ios, as shown in Fig. 4.8 o he
da a used in he p esen s udy. The wood:ba k a io can each up o 80% in E. globulus a 10 yea s
(Guo e al., 2002), bu da a epo ed o E. ni ens a 3 yea s indica e a a he low alue o 45%
(Sims e al., 1999a). Mo eo e , longe o a ions esul in la ge a e age ee size, and he e o e
ha es machine y is be e able o disc imina e be ween lea es and o he ee ac ions, which
educes he nu ien expo s and ash p oduc ion. Ba k and lea es con ain he highes amoun s o
ash in all abo eg ound biomass compa men s, wi h epo ed alues o 1.5-2 imes (Pé ez e al.,
2008), and e en 10 imes (Ragland & Ae s, 1991) he wood ash con en ; his is an impo an
APPLICATION OF CALORIMETRY AND THERMAL ANALYSIS TO STUDY THE STABILIZATION OF
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115
5. Applica ion o calo ime y and he mal analysis o
s udy he s abiliza ion o soil o ganic ma e in
a o es ed soils
Abs ac
The s udy o soil o ganic ma e dynamics equi es highly ep oducible and accu a e
echniques o applica ion o la ge numbe s o samples. This is especially impo an o modelling
changes in soil o ganic ma e in ela ion o land use changes, as equi ed by he Kyo o p o ocol.
The main objec i e o his s udy was o apply calo ime y and he mal analysis, as no el
echniques o elucida e how a o es a ion a ec s he na u e o SOM and soil mic obial me abolism.
The echniques we e applied o s udy he SOM dynamics in wo a o es ed s ands di e ing in he
ee species used, Pinus adia a and Eucalyp us globulus, es ablished on pas u es in a humid
empe a e egion. The applica ion o di e en ial scanning calo ime y and solid s a e nuclea
magne ic esonance e ealed ha he soil o ganic ma e was cons i u ed by ca bohyd a es,
ca bonyl/ca boxyl g oups, alipha ic componen s and a oma ic ca bon in he i s yea s o he
o a ion. All hese ac ions became deg aded a e a o es a ion. The deg ada ion was moni o ed
by calo espi ome y, which p o ided he calo espi ome ic a io o he soil basal me abolism,
oge he wi h he ac i e biomass and he me abolic quo ien . These indexes p o ed o be sensi i e
pa ame e s ha p o ided in o ma ion abou changes in he pa e n o mic obial me abolism in
esponse o changes in he na u e and edox s a e o he ca bon subs a es, demons a ing
deg ada ion o he a oma ic and alipha ic o ganic ma e ac ion. The echniques we e able o
dis inguish di e ences in soil o ganic ma e dynamics in he wo ypes o s ands, a ibu able o he
di e en de elopmen o unde s o y ege a ion and li e composi ion.
Keywo ds: calo ime y, he mal analysis, a o es a ion, SOM, biodeg ada ion.
5.1. In oduc ion
Changes in land co e and ce ain ypes o land managemen (such as in ensi e o es y and
ag icul u e), wild i es, and d ainage al e he pools and u no e a es o soil o ganic ca bon (SOC).
Since soils ep esen one o he la ges ese oi s o o ganic C on a global scale, huge amoun s o
CO2 and o he g eenhouse gases a e being ans e ed om he soil o he a mosphe e as a
consequence o such ac i i ies. Al hough impo an ad ances ha e been made in esea ch on his

CHAPTER V
116
opic in he las decade, cu en knowledge o he mechanisms in ol ed in he dynamics o soil
o ganic ma e (SOM) s ill does no enable p edic ion o he ecosys em esponse o such
pe u ba ions.
A subs an ial pa o SOM can be es o ed by means o con e sion o a able land o o es
land. Fo his eason, a o es a ion is a majo s a egy included in he Kyo o P o ocol on clima e
change, because o he capaci y o o es s o es o e C in biomass and soils. Al hough hese
measu es con ibu e o C seques a ion in biomass, he impac on soil C is less clea . Since C
seques a ion in soils is in luenced by nume ous ac o s, such as p e ious land use, clima e and
ee species (Paul e al., 2002), i is di icul o es ablish a common p o ocol p edic ing he changes
in C in ela ion o a o es a ion. Thus, di e en s udies ha e de ec ed impo an dec eases in SOM
du ing he i s yea s a e a o es a ion as a consequence o he inc eased C mine aliza ion
(Tu ne & Lambe , 2000; Da is & Cond on, 2002). The loss o SOM is a ibu ed o he educed
inpu s o labile o ganic compounds o he mine al soil, which c ea es an imbalance be ween inpu s
o C and espi ed C (Chen e al., 2000; Sagga e al., 2001), indica ing he c ucial ole o
mic oo ganism ac i i y in SOM dynamics. One o he mos impo an di icul ies in modelling he
soil C seques a ion ha occu s a e a o es a ion is he complexi y o he SOM dynamics,
esul ing om simul aneous mechanisms, such as molecula ecalci ance, spa ial inaccessibili y o
he decompose and s abiliza ion by clays and ions (e.g. Sollins e al., 1996; on Lü zow e al.,
2006). Mo eo e , i is known ha he deg ada ion o ecalci an OM can easily ake place in uppe
ho izons (80% o he SOM in mos soils), in which o he s abiliza ion mechanisms, such as he
spa ial inaccessibili y o mic oo ganism o SOM and enzymes o in e ac ion wi h mine al su aces
and me al ions, a e less ac i e han in deepe soil ho izons ( on Lü zow e al., 2006). As a
consequence, SOM u no e is usually apid in he uppe ho izons, bu akes longe a g ea e
dep hs (Fie e e al., 2003; Gobe na e al., 2006). Fo all o hese easons, e alua ion o he e ec s
o a o es a ion on C balance and SOM u no e mus be made by cha ac e iza ion o he
composi ion and he s abili y o SOM subs ances and by he use o indica o s o mic obial ac i i y.
Analy ical echniques such as solid-s a e 13 C CP-MAS NMR, Fou ie ans o m in a ed
spec oscopy and py olysis/GC-MS a e widely used o cha ac e ize he s uc u e and composi ion
o SOM. In addi ion, di e en ac iona ion me hods ha e been de eloped in he las decade o
e alua e he ela i e abundance o labile and ecalci an o ms o C (e.g on Lü zow e al., 2007).
Same examples o such ac iona ion app oaches include chemical and physical p ocedu es (Sohi
e al., 2001; Ro i a & Vallejo, 2002; Ma io & Wande , 2006). Mo eo e , mic obial bioma ke s and
compound-speci ic s able iso ope and adioca bon analysis enable di e en ia ion o unc ional
ac ions (Re hemeye e al., 2004; B o kin e al., 2008). All o hese s a egies cons i u e aluable
ools ha ha e p o ided impo an insigh s in o SOM dynamics. Howe e , some s udies on
dynamics o SOM, especially hose ocussed on modelling, equi e simple echniques ha could be
used o la ge numbe o samples, while a he same ime o e ing a high deg ee o ep oducibili y
and accu acy. In his sense, calo ime y and he mal echniques a oid he need o some o hese
long p ocedu es, and p o ide quan i a i e assessmen o SOM u no e and s abiliza ion.
APPLICATION OF CALORIMETRY AND THERMAL ANALYSIS TO STUDY THE STABILIZATION OF
SOIL ORGANIC MATTER IN AFFORESTED SOILS
117
In ecen yea s, calo ime y and he mal analysis ha e been use o mee he inc easing
demand o apid and mo e ep oducible assessmen o SOM p ope ies (Ba os e al., 2007).
Di e en ial Scanning Calo ime y (DSC) p o ides in o ma ion abou he mal p ope ies o SOM in
ela ion o i s composi ion and s abiliza ion. These echniques a e based on he di e en
empe a u es o exo he mic decomposi ion o ca bohyd a es and ca boxyl g oups, alipha ic
subs ances and mo e e ac o y a oma ic C. Thus, DSC has been used o o e a ela i ely apid
and simple analy ical me hod o s udy SOM ac ions o soils subjec ed o di e en ypes o
managemen o pe u ba ions, such as wild i es (De la Rosa e al., 2008; Duguy & Ro i a, 2010),
land uses changes (Lopez-Capel e al., 2005; Salgado e al., 2010) and in ensi e illage (Plan e e
al., 2005). The combined use o DSC and o he analy ical echniques enables be e
cha ac e iza ion o SOM. Thus, ecen s udies ha e combined DSC wi h e.g. mic obial ac i i y
indica o s (Ma ina i e al., 2010), SOM chemical and physical ac iona ion (Dell'Aba e e al., 2002;
Lopez-Capel e al., 2005; Plan e e al., 2005), changes in iso opic C (Kuzyako e al., 2006;
Do odniko e al., 2007), py olysis/GC-MS (De la Rosa e al., 2008), Fou ie ans o m in a ed
spec oscopy (Ma ina i e al., 2010) and NMR (Lopez-Capel e al., 2005; Ba os e al., 2011).
In he s udy o he ela ionships be ween mic obial ac i i y and SOM s abiliza ion, ce ain
indica o s such as he mic obial biomass pool, he mic obial quo ien (mic obial biomass/SOC) and
me abolic quo ien (soil espi a ion/mic obial biomass, qCO2) ha e been used o assess subs a e
deg adabili y and he deg ee o subs a e limi a ion o soil mic obes (Dilly & Munch, 1998; Bas ida
e al., 2008). Thus, he applica ion o hese pa ame e s p o ides in o ma ion abou how apidly
o ganic subs a es a e me abolized.
Soil mic obial me abolism can also be measu ed by iso he mal calo ime y, which has been
used o s udy me abolism in mic oo ganisms, animals and plan s (Hansen e al., 2002). Despi e
he di e en ad an ages o his echnique, i s applica ion o soils is s ill qui e limi ed (Ba os e al.,
2007; Ba os e al., 2011). Since his echnique is no in asi e, i can imp o e he accu acy and
ep oducibili y o he de e mina ions. I is also a simple, sensi i e and eliable echnique, which
educes he p oblems de i ed om he leng hy handling p ocedu es, and enables con inuous
moni o ing o soil mic obial ac i i y.
Thus, calo ime y p o ides da a on mic obial biomass (Spa ling, 1983) and simul aneous
measu emen o me abolic hea a e (Φ) and soil espi a ion, da a ha a e well co ela ed wi h
hose measu ed by o he mo e adi ional echniques (Spa ling, 1981; C i e e al., 2004b).
Mo eo e his echnique can also p o ide quan i a i e indices o mic obial me abolism (such as he
hea eleased pe uni o mic obial biomass), which p o ide in o ma ion abou he e iciency o
ca bon u iliza ion by soil mic oo ganisms (Ba os & Feijóo, 2003; Zheng e al., 2009). Ano he
use ul and no el index ob ained by his echnique is he calo espi ome ic a io (Φ/RCO2), which
p o ides in o ma ion abou he edox s a e o subs a es being me abolized by he mic oo ganisms,
and he e iciency o con e sion o subs a e ca bon in o li ing cells in p ocesses associa ed wi h
mic obial biomass gain (Hansen e al., 2004; Wadsö e al., 2004). This pa ame e has been
success ully used in plan s and insec s udies (Aca e al., 2004; Summe s e al., 2009), bu
CHAPTER V
118
de e mina ion o he Φ/RCO2, was no epo ed o basal me abolism in soils un il ecen ly (Ba os
e al., 2011). The la e s udy shows ha measu emen s o his a io can p o ide in o ma ion on he
na u e o he o ganic subs a es being deg aded in he soil and may he e o e con ibu e o
imp o ing ou knowledge abou SOM u no e .
The main objec i e o his s udy was o use calo ime y and he mal analysis o elucida e how
a o es a ion a ec s he na u e and dynamics o SOM in a humid empe a e egion, whe e he
SOM dynamics a e pa icula ly apid. DSC was used in combina ion wi h 13C CP-MAS NMR o
s udy he changes in SOM h oughou he o a ion, a e a o es a ion. The e ec o changes in
SOM composi ion on mic obial me abolism was s udied by iso he mal calo ime y. This should
con ibu e o ou unde s anding o he SOM s abiliza ion p ocesses by p o iding new insigh in o
SOM p ope ies.
5.2. Ma e ial and Me hods
5.2.1. S ands selec ed and sampling
The s udy was ca ied ou in NW Spain (Lugo). All s ands we e loca ed on o me pas u es, in
which low in ensi e managemen was applied o e many yea s, and which ha e ecen ly been
a o es ed wi h E. globulus and P. adia a. The s ands we e loca ed no mo e han 30 km apa and
hey had compa able land use his o y p io o a o es a ion. Simila o es managemen was ca ied
ou in each ype o o es plan a ion. To asce ain ha all si es we e simila as ega ds soil ype and
land use, selec ion o he s udy si es was based on di ec obse a ion o he e ain o adjacen
pas u es, ep esen ing he a e age endency o each species epo ed in Chap e II, as well as
consul a ions wi h local landowne s.
The ages o he Eucalyp us globulus s ands we e 1, 5 and 18 y , and o he Pinus adia a
s ands 3, 13, 28, 35 and 40 y , which co esponded o di e en s ages o he o a ion o hese
species in he egion (15-18 y in he o me and 35-40 y in he la e ). These s ages we e: (i)
es ablishmen (s ands 1E and 3P), which in he eucalyp s and pine s ands a e 1 and 3 y o age,
espec i ely; (ii) young s ages, immedia ely a e canopy closu e (5E and 13P); (iii) ma u e
plan a ions (28 and 35P), and (i ) end o o a ion (18E and 40P).
The 20 yea annual a e age ain all o he a ea is 1158 mm, and he empe a u e, 15.1 ºC. The
we es mon h is No embe , wi h an a e age ain all o 139 mm, and he d ies Augus , wi h 45
mm. The lowes mean mon hly empe a u e 9.7 ºC occu s in Feb ua y, and he highes 19.1 ºC, in
Augus . The soils we e de eloped om schis and qua zi e, and we e classi ied as Alumi-humic
Umb isol (IUSS Wo king G oup WRB, 2006). The soil has a loam o sandy loam ex u e and is well
d ained. The A ho izon is ich in o ganic ma e and s ongly acidic (Table 5.1). The soil humidi y
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119
and empe a u e egimes a e Udic (mean pe iod wi h pa ial d ough , 1 mon h) and Mesic (mean
os - ee pe iod, 10 mon hs), espec i ely.
Table 5.1. Cha ac e is ics o s ands and selec ed p ope ies o he soil samples (0-5 cm), and o ganic laye .
Age
S ocking T ee heigh O ganic Laye Clay
T ee Species Sample (y ) ( ee ha-1) (m) (Mg ha-1) pH (%) Soil Tex u e
Eucalyp us globulus 1E 1 1146 1.3 0.00 5.88 13 Loam
5E 5 1432 7.7 2.70 5.57 15 Sandy Loam
18E 18 1146 23.0 10.14 4.95 11 Loam
Pinus adia a 3P 3 668 1.91 0.31 5.82 16 Sil y Loam
13P 13 891 15.15 30.96 5.62 17 Loam
28P 28 859 20.46 56.22 5.32 5 Sandy Loam
35P 30 923 19.54 49.07 5.36 6 Sandy Loam
40P 40 923 25.05 69.32 4.69 17 Sil y Loam
Fo soil sampling, a 50 m x 50 m plo was selec ed wi hin he s and, a a dis ance o mo e han
30 m om he edge o he s and. In each plo , o es loo and mine al soil samples we e aken a 8
andomly dis ibu ed poin s. The o ganic ho izons we e collec ed wi h he aid o a ame (25 cm x
25 cm). Sub-samples o he mine al soil laye (0-5 cm) we e collec ed wi h a s eel co e , and we e
combined o o m one bulk sample pe plo . Si e p epa a ion o o es es ablishmen consis ed o
ipping, and no e iliza ion, illage o weed con ol was ca ied ou in he plan a ions.
5.2.2. Gene al soil p ope ies
The pH o he soil was measu ed in 0.1 M KCl wi h a glass elec ode. To al C and N we e
analyzed wi h a LECO Elemen al analyze (LECO T uSpec CHNS). Soil pa icle analysis was
pe o med by lase di ac ome y, wi h a Mas e size 2000 di ac ome e .
5.2.3. The mal analysis
The soil was d ied and gen ly g ound in an aga e mo a o DSC measu emen s (DSC Q100
TA ins umen s). These expe imen s we e conduc ed a a hea ing a e o 10°C min–1 unde a lux
o d y ai om 20 o 600 ºC, as p e iously desc ibed (Dell'Aba e e al., 2000). The di ec in eg al o
he exo he mic DSC cu es unde he lux o d ied ai wi h espec o ze o gi es he hea o
combus ion o he soil in kJ g-1. All measu emen s we e made on d y weigh basis.
CHAPTER V
120
5.2.4. Calo ime ic measu emen s
Soil samples we e sie ed (2 mm) and s o ed a 4 ºC in polye hylene bags. P io o calo ime ic
expe imen s, samples we e b ough o 25% mois u e con en , and incuba ed o abou 24 hou s a
he empe a u e o he calo ime ic measu emen s, 25ºC.
The soil basal me abolism was moni o ed in a TAM 2277 calo ime e (TA Ins umen s), which
is a e y sensi i e hea conduc ion calo ime e wi h 3 calo ime e channels. Each channel has wo
calo ime e ampoules: one o he sample and he o he o e e ence samples. The calo ime e
was s a ically calib a ed o he soil measu emen s a an ampli ie se ing o 300 mic owa s (μW).
Each soil sample was p epa ed o calo ime ic measu emen s a e equilib a ing a 25 ºC by
weighing 1.5 g in o h ee 4 ml s ainless s eal ampoules; he open ampoules we e hen le ,
oge he wi h a ial con aining wa e , in a sealed polye hylene bag, o 48 hou s. This ea men
allows he soil me abolism o equilib a e om he s o age empe a u e, 4ºC, o he measu emen
empe a u e, 25ºC, and allows he samples o each apou equilib ium. A small ial con aining 0.2
mL o 0.4M NaOH was hen placed in one o he sample ampoules. The h ee sample ampoules
we e hen closed and placed in he calo ime e a he same ime, oge he wi h he e e ence
ampoules illed wi h silica sand.
The calo ime ic channels wi h soil measu e basal me abolic hea a e, Φ con inuously in
mic owa s, μW o μJ s-1, while he channel wi h NaOH measu es he soil basal me abolic hea a e
plus he hea a e om eac ion be ween me abolic CO2 and NaOH, bo h o which a e exo he mic.
The en halpy o he CO2 eac ion is -108.5 kJ mol-1 a his concen a ion o NaOH (C iddle e al.,
1991; Russell e al., 2006). Φ was measu ed a 3 minu e in e als o be ween 20 and 48 hou s. A
he end o he expe imen , he NaOH was emo ed om he calo ime e and he sample esealed
and eplaced in he calo ime e o check he basal me abolic a e o he soil sample con aining he
NaOH. This p ocedu e enables he ep oducibili y o he egis e ed basal me abolism in he h ee
soil samples o be checked.
The me abolic hea a e, Φ, he a e o CO2 p oduc ion, RCO2, and he a io o me abolic hea
a e o CO2 a e, Φ/RCO2, we e calcula ed om he abula ed Φ da a by a e aging he Φ alues
om he wo channels wi h only soil and sub ac ing he alues om he Φ measu ed om he soil
sample wi h NaOH. The esul s ob ained a e he abula ed Φ da a o he eac ion be ween he
CO2 and he NaOH, which we e hen di ided by he en halpy change (-108.5 kJ mol-1) o he
eac ion be ween he NaOH and he CO2, o gi e RCO2 a each da a poin in mol CO2 pe second.
The quo ien be ween he basal me abolic Φ and he abula ed RCO2 alues yields Φ/RCO2. The
Φ, RCO2, and Φ/RCO2 can be epo ed quan i a i ely as he a e age alues o he abula ed da a.
The s anda d de ia ion o he abula ed da a p o ides in o ma ion abou he a iabili y in hese
alues. The quan i a i e RCO2 was ela ed o he ac i e biomass o gi e he me abolic quo ien ,
qCO2. Soil ac i e biomass was calcula ed by he Spa ling me hod (Spa ling, 1983) and ela ed o
he soil C con en o gi e he a io o mic oo ganisms o soil ca bon, Cmic-C.

APPLICATION OF CALORIMETRY AND THERMAL ANALYSIS TO STUDY THE STABILIZATION OF
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121
5.2.5. Solid s a e 13C CP-MAS NMR
Solid NMR expe imen s we e pe o med a 298 K in a 17.6 T Va ian Ino a-750 spec ome e
(ope a ing a 750 MHz p o on equency) equipped wi h a T3 Va ian solid p obe (Agilen , Inc,
USA). Solid NMR samples we e p epa ed in 3.2 mm o o s wi h an e ec i e sample capaci y o 22
µL, which co esponds o app oxima ely 30 mg o he powde ed sample. Ca bon chemical shi s
we e e e ed o he ca bon me hylene signal o solid adaman ine, a 28.92 ppm. This sample was
also used o calib a e he 1D CP-MAS expe imen s.
C oss Pola iza ion Magic Angle Spinning (1D CP-MAS) expe imen s we e ca ied ou wi h he
samples, unde he ollowing condi ions: he in e -scan delay was se a 0.5 s, he numbe o scans
was 100000 and he MAS a e was 15 kHz. He e onuclea decoupling du ing acquisi ion o he FID
was pe o med wi h Spinal-64, a a p o on ield s eng h o 70 kHz. The c oss pola iza ion ime was
se a 1 ms. Du ing c oss pola iza ion, he ield s eng h o he p o on pulse was held cons an a 75
kHz, and ha o he 13C pulse was linea ly amped wi h a 20 kHz amp nea he ma ching
sideband. The NMR spec a we e p ocessed and he a ea o he signals was quan i ied wi h
Mes eNo a so wa e (Mes elab Resea ch inc).
5.2.6. S a is ical analysis
The quan i a i e indices a e gi en as he a e age o h ee eplica es and he s anda d
de ia ion. The da a we e compa ed by g aphical analysis. All he co ela ions we e signi ican a
p<0.05.
5.3. Resul s
5.3.1. Changes in he SOM in he a o es ed soils
The changes in he soil o ganic laye and SOC in he uppe mos , supe icial mine al soil laye
(0-5 cm) h oughou he o a ion pe iod o each species (15 y and 35-40 y a e he usual o a ion
pe iods o E. globulus and P. adia a in he egion) a e shown in Table 5.1, and as expec ed, li e
accumula ion inc eased wi h age in bo h ypes o s ands, al hough he p ocess was much as e in
he pine s ands han in he eucalyp us s ands. In he P. adia a s ands li e accumula ion s a ed
ea lie , and he amoun accumula ed a he end o he o a ion was 7 imes highe han in he la e .
The mine al soils o bo h plan a ions we e subjec ed o la ge dec eases in SOC h oughou he
o a ion. The soils unde pines los mo e SOC (maximum eco ded loss, 70% a e 30 y ) and o e
a longe ime ha he soil unde eucalyp us (maximum eco ded, 50% a e 5 y ). A he end o he
o a ion bo h soils pa ially eco e ed hei SOC con en s. In he pine ch onosequence, he C gain
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in mine al soil occu ed when he li e accumula ion was close o s eady s a e. The C/N a io
dec eased in he same way as SOC (Table 5.2), and eached alues o a ound 10 in he soils wi h
he highes SOC losses.
Table 5.2. SOC, SON and SOM con en s o he samples, oge he wi h he ca bon o ni ogen a io (C/N) and he
mic obial ac i e biomass.
T ee Species Samples C (%) N (%) C/N SOM(1) (%)
Mic obial
Biomass
(μg CX g-1)
E. globulus 1E 11.0 0.83 13.2 24.07±0.45 553±16
5E 5.2 0.56 9.3 12.53±0.80 387±28
18E 9.1 0.75 12.2 17.37±0.46 270±14
P. adia a 3P 12.4 0.88 14.1 27.22±1.77 767±98
13P 6.5 0.47 13.9 16.97±0.19 475±97
28P 3.7 0.35 10.5 5.26 ± 0.10 273±19
35P 4.4 0.44 10.0 9.41±0.18 69±12
40P 6.7 0.46 14.7 13.00±0.33 183±45
(1) Soil o ganic ma e .
5.3.2. SOM composi ion in he mine al soil ho izon: DSC and NMR
The hea o combus ion (Q) o he soil samples, in Joules pe g am o soil, de e mined by
di ec in eg a ion o DSC cu es (Fig. 5.1), and he maximum hea o combus ion empe a u es o
SOM a e shown in Table 5.3. Q was posi i ely co ela ed wi h SOC and SOM (R2 = 0.83 p< 0.001;
R2 = 0.88 p<0.001 espec i ely), e lec ing he di ec connec ion be ween Q and he SOM con en
o he samples. Such co ela ions ha e been epo ed in p e ious s udies (Ba os e al., 2008) and
indica e ha he hea o combus ion o he soil, de e mined by DSC, is only a unc ion o he SOC
and SOM con en s when gi en in Joules pe soil mass. Thus, he la ges a eas limi ed by he DSC
cu es o samples 1E and 3P was ela ed o he highe SOM con en s, whe eas he small a eas
limi ed by he DSC cu es o samples 5E, 28P and 35P co esponded o he lowe SOM con en s.
Typical DSC cu es o he soil samples o he ch onosequences o eucalyp s and pine
espec i ely, a e shown in Figs. 5.1a and 5.1b. Di e en s udies ha e demons a ed ha hese
cu es e lec he p ope ies o he di e en o ganic compounds cons i u ing he SOM, on he basis
o hei di e en he mal s abili ies (Ba os e al., 2007).
In all soils, he DSC cu es exhibi a p ominen exo he mic combus ion peak in a na ow ange
o 325-339 ºC, which is a ibu ed o he combus ion o ca bohyd a es (Dell'Aba e e al., 2002;
Lopez-Capel e al., 2005), and named Exo 1 (G isi e al., 1998). The heigh s o hese Exo 1 peaks
a ied g ea ly in he samples, ollowing he changes in C con en h oughou a o es a ion.
APPLICATION OF CALORIMETRY AND THERMAL ANALYSIS TO STUDY THE STABILIZATION OF
SOIL ORGANIC MATTER IN AFFORESTED SOILS
123
a
b
Figu e 5.1. DSC cu es o soil mine al samples (0-5 cm) om he E. globulus s ands (Fig. 5.1a) and P. adia a s ands
(Fig. 5.1b). Di e en heigh s e lec di e en SOM con en s. The name o he sample deno es he age o he s and and
he ee species (e.g. 1E: one-yea -old eucalyp us s and). Each cu e ep esen s he a e age o h ee eplica es.
In acco dance wi h he highe SOM con en s, he samples o he younges s ands o each
ch onosequence (1E and 3P) exhibi ed he highes Exo 1 peaks (Figs. 5.1 and 5.2). In hese
samples, a seconda y peak, named Exo 2, wi h a maximum a abou 380 ºC and a ail un il abou
500 ºC, was also dis inguished. In his peak he hea low gene a ed can be a ibu ed o alipha ic C
and ul ic acids (Cuype s e al., 2002; Ba os e al., 2011), whe eas he hea low a empe a u es
highe han 400 ºC would e lec he p esence o a oma ic compounds in he SOM (Leinwebe &
Schul en, 1992; Leinwebe & Schul en, 1999). Thus, acco ding o his in e p e a ion, he SOM in
hese samples, co esponding o he i s yea s a e a o es a ion, was cha ac e ized by la ge
amoun s o ca bohyd a es and ca boxylic C, and lowe amoun s o alipha ic and a oma ic
compounds.
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124
Table 5.3. The mal p ope ies o he soil samples. Hea o combus ion (Q) o he soil, and combus ion empe a u es o
Exo 1 and Exo 2 peaks in he DSC cu es. Tª end is he empe a u e a which he combus ion ended. The names o
he samples deno e he age o he s and and he ee species (e.g. 1E: one-yea -old E. globulus s and). Da a ep esen
he a e age o 3 eplica es. N=3 ± SD.
T ee Species Samples Q (kJ g-1) Exo 1
T1 (ºC)
Exo 2
T2 (ºC)
Tª end
(ºC)
E. globulus 1E 3.92±0.06 332 ±1 395±1 539±3
5E 1.91±0.01 325 ±2 395±2 505±5
18E 2.13±0.03 329 ±1 490±1
P. adia a 3P 4.45±0.09 330±1 398±2 539±2
13P 2.54±0.03 330±1 417±5 520±1
28P 1.08± 331±1 414±3 502±1
35P 1.13±0.01 326±1 427±2 502±1
40P 1.65±0.01 339±1 427±1 516±4
Figu e 5.2. DSC cu es o samples aken in he mos ecen a o es ed soils (1E and 3P a e he samples aken om
E. globulus and P. adia a plan a ions, 1 and 3 y a e a o es a ion, espec i ely). The combus ion empe a u es
indica e he same SOM composi ion in bo h samples. Each cu e ep esen s he a e age o h ee eplica es.
Cha ac e iza ion o SOM in he soils om he younges s ands was complemen ed by 13C CP-
MAS NMR analysis o he P. adia a samples (Fig. 5.3). The 13C CP-MAS NMR spec um o he
sample 3P, e ealed he p esence o signal co esponding o sa u a ed alipha ic chains, b anched
alkyl-C and CH3O-C g oups (0-60 ppm), ca bohyd a e C (55-110 ppm), a oma ic g oups (110-165
ppm) and ca boxylic C (165-200 ppm). The mos p e alen signals in he 13C CP-MAS spec um
co espond o a b oad band in he egion 45–110 ppm. This egion is ypical o O-alkyl C g oups
and is gene ally a ibu ed o polysaccha ide ma e ial such as cellulose (Kögel-Knabne , 1997). In
he alipha ic egion, he spec um shows wo peaks, one a 32 ppm assigned o ace yl C and
me hyl C in lipid, cu in, sube in o amino acids (Golchin e al., 1996), and he o he a 55 ppm,