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Dead wood p o ile o a semi-na u al bo eal o es : implica ions o sampling
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Halme, P.; Pu honen, J.; Ma jakangas, E.-L.; Komonen, A.; Juu ilainen, K.; Ab ego,
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Halme, P., Pu honen, J., Ma jakangas, E.-L., Komonen, A., Juu ilainen, K., & Ab ego, N. (2019).
Dead wood p o ile o a semi-na u al bo eal o es : implica ions o sampling. Sil a Fennica,
53(4), A icle 10010. h ps://doi.o g/10.14214/s .10010
2019
1
SILVA FENNICA
Sil a Fennica ol. 53 no. 4 a icle id 10010
Ca ego y: esea ch a icle
h ps://doi.o g/10.14214/s .10010
h p://www.sil a ennica. i
Licenced CC BY-SA 4.0
ISSN-L 0037-5330 | ISSN 2242-4075 (Online)
The Finnish Socie y o Fo es Science
Panu Halme1,2, Jenna Pu honen1,2, Emma-Liina Ma jakangas3, A e Komonen1,2,
Ka ja Juu ilainen1 and Ne ea Ab ego4
Dead wood p o ile o a semi-na u al bo eal o es –
implica ions o sampling
Halme P., Pu honen J., Ma jakangas E.-L., Komonen A., Juu ilainen K., Ab ego N. (2019).
Dead wood p o ile o a semi-na u al bo eal o es – implica ions o sampling. Sil a Fennica ol.
53 no. 4 a icle id 10010. 14 p. h ps://doi.o g/10.14214/s .10010
Highligh s
•We cons uc ed a ull dead wood p o ile o a semi-na u al bo eal o es .
•Abundance-diame e dis ibu ions we e di e en among ee species.
•Ex ensi e sampling is needed i ocus on la ge dead wood and a e ee species.
Abs ac
Dead wood p o ile o a o es is a use ul ool o desc ibing o es cha ac e is ics and assessing
o es dis u bance his o y. Ne e heless, he e a e ew s udies on dead wood p o iles, including bo h
coa se and ine dead wood, and on he e ec o sampling in ensi y on he dead wood es ima es.
In a semi-na u al bo eal o es , we measu ed e e y dead wood i em o e 2 cm in diame e om
80 s udy plo s. F om eigh plo s, we u he eco ded dead wood i ems below 2 cm in diame e .
Based on hese da a we cons uc ed he ull dead wood p o ile, i.e. he o e all numbe o dead
wood i ems and hei dis ibu ion among di e en ee species, olumes o di e en size and decay
s age ca ego ies. We disco e ed ha while he numbe o small dead wood i ems was immense,
hei numbe d opped d as ically om he diame e below 1 cm o diame e s 2–3 cm. Di e en
ee species had no ably di e en abundance-diame e dis ibu ion pa e ns: sp uce dead wood
comp ised mos s ikingly he smalles diame e ac ions, whe eas aspen dead wood comp ised
a la ge sha e o la ge-diame e i ems. Mos o he dead wood olume cons i u ed o la ge pieces
(>10 cm in diame e ), and 62% o olume was bi ch. The a ia ion in he dead wood es ima es
was small o he nume ically dominan ee species and smalles diame e ca ego ies, bu high
o he sub-dominan ee species and la ge size ca ego ies. In conclusion, he mo e he ocus is
on a e ee species and la ge dead wood i ems, he mo e comp ehensi e should he sampling be.
Keywo ds coa se woody deb is; coni e ous o es ; ine woody deb is; o es dis u bance dynam-
ics; o es s uc u e; sap oxylic
Add esses 1 Depa men o Biological and En i onmen al Science, Uni e si y o Jy äskylä, P.O.
Box 35, FI-40014 Uni e si y o Jy äskylä, Finland; 2 School o Resou ce Wisdom, Uni e si y
o Jy äskylä, P.O. Box 35, FI-40014 Uni e si y o Jy äskylä, Finland; 3 Cen e o Biodi e si y
Dynamics, Depa men o Biology, No wegian Uni e si y o Science and Technology, N-7491
T ondheim, No way; 4 Depa men o Ag icul u al Sciences, Uni e si y o Helsinki, P.O. Box 27,
FI-00014 Uni e si y o Helsinki, Finland
E-mail [email p o ec ed]
Recei ed 3 June 2018 Re ised 28 June 2019 Accep ed 18 Sep embe 2019
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Sil a Fennica ol. 53 no. 4 a icle id 10010 · Halme e al. · Dead wood p o ile o a semi-na u al bo eal o es …
1 In oduc ion
Dead wood is a c ucial elemen o all o es ecosys ems and a la ge p opo ion o o es species
is dependen on dead wood a some li e s age (Ha mon e al. 1986; Sii onen 2001; S okland e al.
2012). In na u al bo eal o es s, dead wood olumes a e la ge (Esseen e al. 1997; Sii onen 2001)
and ypically a y be ween 40–170 m3 pe hec a e (Aakala 2010). Much la ge olumes can be
p esen a e s and- eplacing dis u bances such as s o ms (Nilsson e al. 2004), i es (Spies e al.
1988), o ba k bee le ou b eaks (Komonen e al. 2011). In managed bo eal o es s, by con as , he
amoun o dead wood is usually mo e han en- old smalle (Sii onen 2001; bu see E äjää e al.
2010). Due o his educ ion in dead wood amoun , a la ge numbe o dead wood dependen species
has become h ea ened in bo eal o es ecosys ems (Rassi e al. 2001; Sii onen 2001).
The impo ance o dead wood o o es unc ioning and biodi e si y is widely acknowledged.
I is a common p ac ice o moni o dead wood in na ional o es in en o ies (Woodall and Mon-
leon 2008; Finnish Fo es Resea ch Ins i u e 2014; Jonsson e al. 2016), in quali y con ol o he
implemen a ion o managemen guidelines (Päi inen e al. 2011), and as pa o o es ce i ica ion
sys ems (Fo es S ewa dship Council 2010). Dead wood is also measu ed as an explana o y a iable
in s udies on o es dis u bance dynamics (Kuulu ainen 2002), o es biodi e si y (Junninen and
Komonen 2011) o ecosys em unc ioning (Gam eld e al. 2013). In his pape , ou ocus is on
s and-le el measu emen s o dead wood, which a e ypical in o es biodi e si y esea ch.
Dead wood in en o ies ha e adi ionally ocused on coa se woody deb is (CWD, base
diame e ≥ 10 cm); pa ly because he la ge logs comp ise mos biomass, and pa ly because a
la ge p opo ion o he h ea ened dead wood dependen species equi es la ge logs (Tikkanen e
al. 2006; Junninen and Komonen 2011). Fine woody deb is (FWD, base diame e < 10 cm) has
been a ely su eyed, al hough in managed landscapes a la ge p opo ion o dead wood is FWD
(E äjää e al. 2010; Ab ego and Salcedo 2013). Howe e , in e es in FWD has inc eased wi h he
g owing p essu e o o es bio uel ex ac ion (Bouge e al. 2012) and in he USA, o example,
FWD has been moni o ed na ionwide o assess i e isk and ca bon s ocks (Woodall and Liknes
2008; Woodall and Monleon 2008). The e ec o FWD emo al is nega i e on many species g oups
such as lichens, b yophy es and ungi (K uys and Jonsson 1999), bee les (G o e 2009), spide s
(Cas o and Wise 2009) and small mammals (Manning and Edge 2008). FWD also hos s unique
species assemblages o bee les and ungi (Fe o e al. 2009; Bässle e al. 2010; B in e al. 2011;
Juu ilainen e al. 2014) and can be an impo an complemen a y esou ce o CWD o wood-in-
habi ing ungi in managed o es s (No dén e al. 2004; Kü e e al. 2008).
Dead wood p o ile classi ies dead wood i ems based on hei size and decay. Dead wood
p o ile o a o es is a use ul ool o desc ibe o es cha ac e is ics (e.g. dead wood he e ogenei y)
and o assess o es dis u bance his o y (e.g. dead wood con inui y o e 200–500 yea s) (S okland
2001). Likewise, dead wood p o ile may also unc ion as biodi e si y indica o . Dead wood p o-
ile can be cons uc ed based on ei he ee numbe s o olumes. The olume-based dead wood
p o iling is based on eco ding he olume o all – o a sample o – dead ees in ela ion o hei
diame e classes and decay s ages in a gi en a ea. Thus a , dead wood p o iles ha e been p oposed
and implemen ed only o CWD (S okland 2001; Ch is ensen e al. 2005; S okland e al. 2012).
Knowledge on FWD p o iles o di e en o es ypes is gene ally e y limi ed, and mo e in o ma-
ion abou FWD p o iles would imp o e ou unde s anding o o es s uc u e.
To inc ease knowledge abou dead wood p o iles and ela ed sampling me hods, he e is
a need o empi ical da a on dead wood in di e en ecological condi ions, di e en ee species
and dead wood ypes. In his pape , we es ima ed he o al numbe o di e en dead wood ypes –
including FWD – in a semi-na u al bo eal o es , based on an in ensi e sampling. We cons uc ed
he dead wood p o ile o s udy how he numbe and olume o dead wood i ems a ies along he
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Sil a Fennica ol. 53 no. 4 a icle id 10010 · Halme e al. · Dead wood p o ile o a semi-na u al bo eal o es …
dead wood diame e s, along di e en decay s ages and among di e en ee species. We also s udied
how inc easing sampling e o imp o ed he accu acy o he es ima es o dead wood abundance
o di e en ee species and dead wood size classes.
2 Ma e ials and me hods
2.1 S udy si e
The s udy was conduc ed in a p o ec ed semi-na u al o es (Kuusimäki, 108 ha). The o es is
loca ed in he sou he n bo eal zone (Ah i e al. 1968), Cen al Finland (WGS84, 62°80´N, 26°26´E).
A e slash and bu n cul i a ion in he ea ly 19 h cen u y he si e was abandoned a ound 1860s
and has been se aside om human ac ion e e since (s ic na u e ese e since 1980s). No way
sp uce (Picea abies (L.) H. Ka s ., hence o h sp uce) is he dominan ee species (abou 50% o he
s anding olume). Bi ches (Be ula spp.) a e also e y abundan (39%), whe eas Sco s pine (Pinus
syl es is L., 6%, hence o h pine) and aspen (Populus emula L., 4%) a e sca ce . The o es si e is
mainly o he My illus and Oxalis-My illus ype (Cajande 1949), bu he e a e small pea land and
he b- ich o es pa ches. Due o he high olume o dead wood and he high numbe o h ea ened
wood-inhabi ing species (Kun u and Halme 2008) he o es possesses high conse a ion alues.
2.2 Dead wood measu emen s
To es ima e he dead wood quali ies we sampled dead wood wi h h ee complemen a y se -ups.
In all o hem, only hose dead wood i ems ha had hei base inside o he s udy plo (basal poin
inclusion, see S okland e al. 2004) we e conside ed. In some cases, he unk had b oken in o
sepa a e pieces when o a e g ounded. I we could ecognize he pieces o o igina e om he
same i em p io he b eakage, we conside ed hem as one i em. De ached b anches om li ing
ees we e ega ded as sepa a e i ems.
In se -up A, we placed 72 s udy plo s (10 m × 10 m) in 24 iple s. In each iple , he loca ion
o he i s plo was andomly assigned, and he nex wo plo s we e placed 30 and 50 me e s om
he i s plo owa d andom compass di ec ions. We ea hese plo s as i hey we e all andomly
posi ioned because hey a he well ep esen ed he whole o es . On hese plo s, we su eyed e e y
dead wood i em wi h diame e ≥ 2 cm and eco ded he ee species, dead wood ype (s anding,
allen, s ump), leng h, base and op diame e and decay s age ( i e ca ego ies, sensu Ren all 1995).
Fo he ( ela i ely a e) s anding dead wood i ems, we only measu ed he diame e a b eas heigh
(i.e. a 1.3 m heigh ) and he es ima ed diame e a b eaking poin (i hey we e b oken). The heigh
o s anding dead ees was es ima ed om he downed ees o equal size.
In se -up B, we used a hie a chical sampling scheme in which we delinea ed wo andomly
posi ioned 10 m × 10 m plo s on andom loca ions and placed one 2 m × 2 m subplo in he no hwes
co ne . The plo s we e su eyed as in se -up A, and in he subplo s, we addi ionally su eyed he
dead wood i ems wi h diame e s < 2 cm (excluding needles, lea es and de ached pieces o ba k).
In se -up C, we delinea ed six hie a chical plo s as in s udy B wi h he excep ion ha in his
se -up he 2 m × 2 m subplo was posi ioned o each co ne o he plo s. In his se -up we only
eco ded he ee species, la ge-end diame e and decay s age ca ego y o e e y dead wood i em.
Thus, om he se -up C i is only possible o calcula e he numbe o he di e en dead wood ypes,
bu no hei olumes. The loca ion o h ee o hese plo s was andomly chosen wi hin he cen al
a ea o Kuusimäki, as pa o an ea lie s udy (see Juu ilainen e al. 2011), and he loca ion o he
emaining h ee plo s was andomly assigned ac oss he whole a ea (Fig. 1). E en hough some o
4
Sil a Fennica ol. 53 no. 4 a icle id 10010 · Halme e al. · Dead wood p o ile o a semi-na u al bo eal o es …
he plo s we e clus e ed, we ea each plo as an independen eplica e. We acknowledge ha his
is somewha inco ec bu do no see i as a majo p oblem because o e all he plo s a e dis ibu ed
h oughou he si e and we also es ed spa ial au oco ela ion among he dead wood p o ile. The
s udy was conduc ed in 2012, excep o he plo s su eyed by Juu ilainen e al. (2011) in 2007.
2.3 Analyses
In a sample plo in en o y, he es ima o o he o al numbe o dead wood i ems Y is he obse ed
numbe o i ems di ided by he ac ion o he s udy a ea ha has been su eyed (S åhl e al. 2001):
Yy
a
A
i
i
m
i
i
m




1
1
1,
()
whe e m is he numbe o plo s, yi is he numbe o i ems in plo i, ai is he size o he plo i, and
A is he a ea o he s udy si e o which he es ima o is o be compu ed. The o al numbe o dead
wood i ems was es ima ed sepa a ely o each ee species, size classes and decay s ages (see
below). Fo i ems wi h diame e ≥ 2 cm, he plo s co e ed 0.8 ha o he 108 ha si e. Fo he e y
ine woody deb is (<2 cm in diame e ) he plo s co e ed 0.0104 ha, i.e. 104 m2.
To es ima e dead wood olumes in he o es , we used da a om he 74 plo s (se -ups A
and B) om which we had adequa e in o ma ion o olume es ima ion. The olumes o he dead
wood i ems we e calcula ed by using he o mula o a unca ed cone. We epo he es ima ed
mean olumes pe hec a e wi h plo le el s anda d de ia ion and he numbe o dead wood i ems
and plo s hese es ima es a e based on, o e wo di e en size classes (2–9 cm and >10 cm) and
di e en ee species (o o he co esponding g oups).
To cons uc a olume-based dead wood p o ile o each ee species, he mean olume pe
hec a e was di ided among he i e decay s ages and size ca ego ies ( he base diame e 2–9 cm,
10–19 cm, 20–29 cm, 30–39 cm o >40 cm).
Fig. 1. Loca ion o he s udy si e in Cen al Finland and he loca ions o he s udy plo s. Thick
line ep esen s he p o ec ed a ea bo de and hin lines al i ude con ou s. The plo s in he se -up
A a e ma ked wi h black squa es, B wi h g ey iangles and C wi h s a s (see me hods o he
de ailed desc ip ion o he di e en da a collec ion se ups). The h ee plo s loca ed ou side he
p o ec ed a ea a e si ua ed on a s uc u ally simila o es adjoining he p o ec ed a ea.

5
Sil a Fennica ol. 53 no. 4 a icle id 10010 · Halme e al. · Dead wood p o ile o a semi-na u al bo eal o es …
To s udy he e ec o sampling e o on he es ima es o he numbe o dead wood i ems
pe hec a e, we esampled ou da a by andomly selec ing an inc easing numbe o plo s (i … m)
wi h eplacemen , and es ima ed he numbe o dead wood i ems pe hec a e a e e y esampling
s ep. This p ocedu e was epea ed 1000 imes, sepa a ely o FWD and CWD o bi ch, sp uce,
pine and aspen.
We used Mo an´s I es o s udy whe he dead wood p o iles in he plo s we e spa ially
au oco ela ed.
3 Resul s
Al oge he , we measu ed 23 073 dead wood i ems, ou o which 16 145 (70%) we e sp uce, 1331
(6%) pine, 4675 (20%) bi ch, 351 (2%) aspen, and 571 (2%) o he ee species (So bus aucupa ia L.,
Alnus spp., Junipe us communis L., Salix cap ea L. and Tilia co da a Mill.). The o al numbe o
dead wood i ems was es ima ed o be 209 006 190, i.e. 1 935 243 i ems pe hec a e. Conside ing
only CWD, he numbe s we e 58 185 and 539, espec i ely.
The dead wood abundance dis ibu ions a ied o di e en ee species (Fig. 2). Fo sp uce,
99% o he dead wood i ems had a diame e < 1 cm, and he numbe o i ems d opped d as ically
o la ge diame e s. Fo aspen, 92% o he dead wood i ems had a diame e < 1 cm and he numbe
o i ems dec eased mo e g adually wi h diame e han o sp uce. The abundance p o iles o bi ch
and pine we e in e media e. Mos o he a e ee species we e be ween he ex emes (i.e. ei he
e y small o e y la ge dead wood i ems domina ing he dead wood p o ile), al hough he da a
a e limi ed o analyze hei p o iles in de ail (Table 1).
Fig. 2. The size-abundance dis ibu ion o dead wood i ems o di e en ee species. No e ha
size below 2 cm is no indica ed due o hei high numbe : ca. 150 million o sp uce, 37 million
o bi ch, 9 million o pine and 0.5 million o aspen.
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Sil a Fennica ol. 53 no. 4 a icle id 10010 · Halme e al. · Dead wood p o ile o a semi-na u al bo eal o es …
Table 1. The es ima ed mean olume (wi h s anda d e o ) o dead wood (m3/hec a e), he o al and mean numbe (wi h s anda d e o ) o dead wood i ems in he s udy plo s, and he
numbe o plo s pa icula dead wood ype was encoun e ed. Values a e gi en sepa a ely o he wo size classes (2–9 cm and ≥10 cm).
2–9 cm Alnus Be ula B oadlea ed Coni e Junipe us Picea Pinus Populus Salix So bus Unknown To al
Volume (s.e.) 0.05 (0.04) 0.91 (0.16) 0.13 (0.03) 0.01 (0.00) 0.01 (0.01) 1.09 (0.15) 0.16 (0.03) 0.36 (0.13) 0.14 (0.14) 0.29 (0.10) 0.04 (0.01) 3.18 (0.38)
To al n 26 767 132 22 15 625 334 292 7 214 56 2490
n/plo (s.e.) 0.35 (0.24) 10.36 (1.57) 1.78 (0.33) 0.30 (0.11) 0.20 (0.15) 8.45 (0.83) 4.51 (0.83) 3.95 (1.45) 0.09 (0.09) 2.90 (0.59) 0.76 (0.15) 33.65 (2.63)
n o plo s 4 54 41 13 4 72 40 13 1 44 30 74
≥10 cm Alnus Be ula B oadlea ed Coni e Junipe us Picea Pinus Populus Salix So bus Unknown To al
Volume (s.e.) 0.01 (0.01) 53.97 (8.87) 0.91 (0.70) 0.82 (0.60) - 8.18 (2.19) 9.33 (3.58) 11.61 (7.77) 0.12 (0.11) 0.09 (0.07) 2.52 (0.51) 87.55 (11.61)
To al n 1 225 69- 65 28 13 4565 421
n/plo (s.e.) 0.01 (0.01) 3.04 (0.42) 0.08 (0.03) 0.12 (0.04) - 0.88 (0.13) 0.36 (0.09) 0.18 (0.06) 0.05 (0.05) 0.07 (0.04) 0.88 (0.14) 5.68 (0.48)
n o plo s 1 51 68-35 19 8 1 3 35 74
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Sil a Fennica ol. 53 no. 4 a icle id 10010 · Halme e al. · Dead wood p o ile o a semi-na u al bo eal o es …
E en i he numbe o FWD i ems was much la ge han CWD, he la e domina ed in olume
(FWD 3.18 s. CWD 87.55 m3 ha–1, Table 1). Dead wood olumes a ied among di e en ee
species and size classes (Table 1). Mos o he olume o FWD belonged o sp uce (1.09 m3 ha–1),
whe eas mos o he olume o CWD (>10 cm) belonged o bi ch (53.97 m3 ha–1).
Dead wood o di e en ee species we e di e en ly dis ibu ed along he size and decay
s age classes. Bi ch was p esen in all sizes and decay s ages, whe eas la ge sp uces we e e y a e,
pine in ad anced decay s age was la gely missing, and medium-sized aspens we e absen (Table 2).
The esampling simula ions show ha he abundance es ima es o di e en dead wood
ypes we e e y un eliable, i hey we e based on a small numbe o sample plo s (Figs. 3–4). The
es ima es o CWD we e e y un eliable up o 15–20 s udy plo s (Fig. 3). FWD es ima es eached
highe eliabili y wi h lowe numbe o plo s (Fig. 4).
Acco ding o he Mo an´s I es , he numbe o aspen dead wood was spa ially au oco ela ed
(p < 0.001 o bo h FWD and CWD), as well as sp uce FWD (p = 0.04). O he dead wood ac ions
we e no spa ially au oco ela ed (p = 0.36 o bi ch FWD, p = 0.16 o Bi ch CWD, p = 0.11 o
sp uce CWD, p = 0.15 o pine FWD and p = 0.5 o pine CWD).
Table 2. The dead wood p o ile o Be ula spp., Picea abies, Pinus syl es is and Populus
emula, whe e he mean olume pe hec a e (m3 ha–1) is di ided among he i e size classes
and decay s ages.
Be ula 2–9 cm 10–19 cm 20–29 cm 30–39 cm >40 cm
Decay s age 1 0.21 0.16 1.60 2.20 1.62
2 0.28 0.41 2.24 5.53 3.80
30.17 0.80 3.12 2.00 13.30
40.21 0.93 5.29 2.27 3.71
5 0.03 0.70 1.74 1.41 1.16
Picea 2–9 cm 10–19 cm 20–29 cm 30–39 cm >40 cm
Decay s age 1 0.62 1.76 2.04
2 0.31 0.46 1.31 0.72
3 0.10 0.11 0.25 0.75
4 0.04 0.47 0.02 0.16
5 0.02 0.03 0.10
Pinus 2–9 cm 10–19 cm 20–29 cm 30–39 cm >40 cm
Decay s age 1 0.06 1.15 0.89
20.07 0.05 0.66 1.21 2.50
3 0.02 0.01 0.59 1.24
40.01 0.29 0.06 0.22 0.26
5 0.02
Populus 2–9 cm 10–19 cm 20–29 cm 30–39 cm >40 cm
Decay s age 1 0.08 0.72 0.01
2 0.20 0.17 10.52
30.06 0.04
40.01 0.02
5 0.01 0.13
8
Sil a Fennica ol. 53 no. 4 a icle id 10010 · Halme e al. · Dead wood p o ile o a semi-na u al bo eal o es …
Fig. 3. The e ec o sampling e o (i.e. he numbe o 10 m × 10 m plo s) on he eliabili y o he es ima ed amoun
o coa se woody deb is o bi ch, sp uce, pine and aspen. The maximum es ima es (= 1600) o bi ch is no shown o
enable be e compa ison be ween he di e en ee species. The ed lines indica e 95% con idence in e als.
Fig. 4. The e ec o sampling e o (i.e. he numbe o 10 m × 10 m plo s) on he eliabili y o he es ima ed amoun o
ine woody deb is o bi ch, sp uce, pine and aspen. The maximum es ima es o bi ch (= 5600), and o aspen (= 6900)
a e no shown o enable be e compa ison be ween he di e en ee species. The ed lines indica e 95% con idence
in e als.