Co esponding au ho : Yannick Enock Bocko
Copy igh © 2025 Au ho (s) e ain he copy igh o his a icle. This a icle is published unde he e ms o he C ea i e Commons A ibu ion License 4.0.
Ecological impo ance o ees and s uc u e o o es ypes in he Likouala swamp
o es , Republic o Congo
Yannick Enock Bocko 1, *, G e a Ch is ina Da gie 2 and Jean Joël Loume o 1
1 Facul y o Sciences and Technology, Ma ien NGOUABI Uni e si y, BP 69, B azza ille, Republic o Congo.
2 School o Geog aphy, Uni e si y o Leeds, Leeds, Uni ed Kingdom.
Wo ld Jou nal o Ad anced Resea ch and Re iews, 2025, 27(02), 2181-2191
Publica ion his o y: Recei ed on 24 June 2025; e ised on 30 July 2025; accep ed on 02 Augus 2025
A icle DOI: h ps://doi.o g/10.30574/wja .2025.27.2.2832
Abs ac
Cu en knowledge, al hough signi ican , does no ye p o ide a ull unde s anding o he unc ioning o swamp o es s
in Cen al A ica. The aim o his s udy was o es ima e he species impo ance alue index (IVI) and cha ac e ise he
s and s uc u e o h ee o es ypes in he Likouala swamp o es in he no h o he Republic o Congo. The o es
in en o y was ca ied ou in looded o es (FF), pe iodically looded o es (PFF) and e a i me o es (TFF), ocusing
only on ees wi h a diame e o 10 cm o mo e. In each o es ype, species o e y high ecological impo ance alue
made up mo e han 56% o he species eco ded, and hei numbe s inc eased as we mo ed om TFF o FF, wi h a
ma ked p edominance o sciaphy e species. This dominance was co obo a ed by he in e ed J-shaped dis ibu ion
cu es obse ed in he h ee ypes o o es , indica ing good na u al egene a ion. Fu he mo e, he mean alues o
s em densi y pe hec a e dec ease om FF (445±8 s ems/ha) o TFF (351±13 s ems/ha), while hose o basal a ea and
heigh end o inc ease in he same o de , om 30.00±2.1 m2/ha o 35.46±3.2 m2/ha and om 20.26±4.20 m o
26.10±5.82 m espec i ely. In sho , he low ep esen a ion o pionee species sugges s a g adual e olu ion o each ype
o Likouala swamp o es owa ds a ma u e s age, cha ac e ised by a physiognomy domina ed by sciaphy e species.
Keywo ds: Republic o Congo; Likouala swamp o es ; Fo es ypes; Impo ance alue index; S and s uc u e
1. In oduc ion
In he Republic o Congo, swamp o es s accoun o 44% o he o al o es a ea [1]. They a e ypical o he o es s o
he cen al basin o he Congo Basin, which de elop and pe sis on soil ha is looded o pa o he yea , and hen
p esen h ee o es ypes. Congolese swamp o es s, which a e gene ally looded, a e ound in la ge dep essions and
poo ly d ained lowlands [2]. Today, s udies moni o ing de o es a ion and o es deg ada ion highligh a sha p educ ion
in hei o es co e [1]. In ac , we a e wi nessing s ong de o es a ion and o es deg ada ion o acies cha ac e is ic
o Congolese swamp o es s, linked mainly o he ins alla ion o palm g o es, logging and popula ion g ow h in he no h
o he coun y [3]. To a oid high a mosphe ic CO2 emissions linked o he an h opisa ion o swamp o es s, which a e
home o he la ges o es pea land in he wo ld [4], sus ainable managemen measu es a e equi ed.
Ecological esea ch ca ied ou in ecen yea s has e ealed ha a be e unde s anding o he s and s uc u e, lo is ic
di e si y and ca bon s o age capaci y o opical ecosys ems, pa icula ly in de eloping coun ies, is c ucial o hei
sus ainable managemen . Ecological knowledge o ho izon al s uc u e (densi y and basal a ea), diame ic s uc u e
and e ical s uc u e ( ee heigh dis ibu ion) makes i possible o moni o he dynamics o a o es ecosys em in e ms
o plan succession [5–7]. Fo example, he dec ease in densi y and he inc ease in basal a ea indica e a g adual e olu ion
o an Aucoumea klaineana P. o es owa ds a ma u e s age, he es ablishmen o a ain o es [7]. Mo eo e , Pan e al.
[8] no ed a s ong co ela ion be ween ee heigh and o es di e si y. Howe e , i should be no ed ha only s uc u al
Wo ld Jou nal o Ad anced Resea ch and Re iews, 2025, 27(02), 2181-2191
2182
pa ame e s bes explain he spa io empo al a iabili y o ca bon s ocks in opical o es s [9–13]. Fo his eason,
moni o ing he a ia ion o ce ain s uc u al pa ame e s, such as basal a ea, s em densi y, diame ic dis ibu ion and
ee size, is e y c ucial o assessing he impac o human dis u bance on o es dynamics a local and egional scales
[14,15].
Howe e , cu en knowledge, impo an as i is, does no ye allow us o unde s and how opical loodplain o es s,
which a e among he mos complex e es ial ecosys ems in he wo ld, unc ion [16]. Ve y li le ecological esea ch has
been ca ied ou on hese pa icula ecosys ems. Hence he need o ca y ou ecological s udies on he mapping,
s uc u e and lo is ic di e si y, and hen on he ca bon ixa ion and s o age capaci ies o he acies cha ac e is ic o he
swamp o es s o Cen al A ica. I is in his con ex ha he p esen s udy is being ca ied ou , wi h he aim o o es ima e
he species impo ance alue index (IVI) and cha ac e ise he s and s uc u e o h ee o es ypes in he Likouala
swamp o es in he no h o he Republic o Congo.
2. Ma e ials and Me hods
2.1. S udy a ea
Ou s udy a ea has a su ace a ea o 30,000 km2 and belongs o he no h-eas e n Likouala egion o he Congolese
e i o y. I is bounded o he no h by he Dongou (Bondzalé) dis ic , o he eas by he Oubangui i e , o he wes by
he Likouala g assland i e and o he sou h by he Bouanela dis ic [13]. The a e age annual empe a u e and ain all
a e 25.6 °C and 1556.5 mm espec i ely [17]. The soil a e pea y o gleysols [18] and he elie is gene ally la [19].
Vege a ion in Likouala is mainly ep esen ed by swamp o es s ha a e gene ally looded. Th ee o es acies o o es
ypes can be dis inguished as cha ac e is ic o hese swamp o es s [20,21]: looded o es , pe iodically looded o es
and e a i me o es .
2.2. Fo es in en o y
The expe imen al plo s we e se up along h ee ansec s 6 o 9 km long, co e ing: looded o es (FF), pe iodically
looded o es (PFF) and e a i me o es (TFF). Twen y-se en 1600 m2 plo s, nine pe ansec and h ee pe acies,
we e se up in Bondzalé, I anga and Ekolongouma (Table 1). Two plo s o 1 ha each and wo plo s o 0.6 ha each we e
se up espec i ely in he TFF and he FF o he Ekolongouma ansec . Each o he hi y-one plo s was subdi ided in o
400 m2 plo s [22], gi ing a o al o 188 sampling uni s. The o al sampling a ea used co esponds o 7.06 ha.
Table 1 Dis ibu ion o s udy plo s by si e and o es ypes
Si es
Leng h o ansec s
Plo size
Numbe o plo s
To al
FF
PFF
TFF
Bondzalé
6 km
40mx40m
3
3
3
9
I anga
6 km
40mx40m
3
3
3
9
Ekolongouma
9 km
40mx40m
3
3
3
9
100mx100m
/
/
2
2
60mx100m
2
/
/
2
To al
11
9
11
31
FF: looded o es ; PFF: pe iodically looded o es ; TFF: e a i me o es
Only ees wi h a diame e o a leas 10 cm a b eas heigh (dbh) we e measu ed in he s udy plo s o each plo . The
local and scien i ic names o he ees we e de e mined. A he ba ium was se up o species no iden i ied in he ield,
o bo anical iden i ica ion a he na ional he ba ium in B azza ille.
2.3. Da a p ocessing and analysis
2.3.1. Ecological impo ance o ee species
The ecological impo ance alue index (IVI) was calcula ed o each species i in he swamp o es s udied. I co esponds
o he sum o he indices o ela i e equency, ela i e densi y and ela i e dominance o he species [23]:
Wo ld Jou nal o Ad anced Resea ch and Re iews, 2025, 27(02), 2181-2191
2183
𝐼𝑉𝐼 = 𝑅𝑒𝑙𝑎𝑡𝑖𝑣𝑒 𝑓𝑟𝑒𝑞𝑢𝑒𝑛𝑐𝑦 + 𝑅𝑒𝑙𝑎𝑡𝑖𝑣𝑒 𝑑𝑒𝑛𝑠𝑖𝑡𝑦 + 𝑅𝑒𝑙𝑎𝑡𝑖𝑣𝑒 𝑑𝑜𝑚𝑖𝑛𝑎𝑛𝑐𝑒 ………. (1)
The ela i e equency o species i is he a io be ween i s equency (numbe o eco ds in which i is p esen ) and he
sum o he equencies o all he species, mul iplied by 100. Rela i e densi y is he a io be ween he numbe o
indi iduals o he species and he o al numbe o indi iduals, mul iplied by 100. Rela i e dominance is he a io
be ween he o al basal a ea o a species and he sum o he basal a eas o all he species, mul iplied by 100.
2.3.2. Ho izon al s uc u e
I was assessed by calcula ing densi y and basal a ea:
𝐷𝑒𝑛𝑠𝑖𝑡𝑦 = Numbe o indi iduals (ni)
Pe hec a e (1ha) …… (2)
𝐵𝑎𝑠𝑎𝑙 𝑎𝑟𝑒𝑎 = π
4∑𝑑𝑖2
𝑛
𝑖=1 …….. (3)
Wi h di = diame e o indi idual i and n = numbe o indi iduals
2.3.3. Ve ical s uc u e
I was assessed by he dis ibu ion o ee heigh s by dhp class o ampli ude 10 cm [24], a he le el o looded o es ,
pe iodically looded o es and e a i me o es . Only he heigh o 20 ees o diame e classes I]10-20], II ]20-30], III
]30-40], IV]40-50] and class V≥50 cm was aken.
2.3.4. Diame ic s uc u e
T ees o dbh ≥ 10 cm we e di ided in o diame e classes o 10 cm ampli ude and he numbe o ees pe diame e class
we e de e mined [25].
3. Resul s
3.1. Ecological impo ance o ee species
O he 68, 50 and 51 ee species eco ded, he numbe o hose wi h a high ecological impo ance alue was 7, 9 and 10
espec i ely o he e a i me o es (TFF), he looded o es (FF) and he pe iodically looded o es (PFF). Ca apa
p oce a DC., Symphonia globuli e a L. ., Uapaca mole Pax, G osse a mac an ha Pax, D ype es occiden alis (Müll. A g.)
Hu ch., En and oph agma palus e S ane , Xylopia ubescens Oli ., Manilka a ouilloyana Aub é . & Pelleg . and
E iocoelum mic ospe mum Gilg ex Radlk. we e, in descending o de , he nine species o g ea es ecological impo ance
in he FF (Table 2).
Table 2 Impo ance alue index (IVI) o species e ol ing in he o es ypes o he Likouala swamp o es (SF)
Species
IVI
FF
PFF
TFF
SF
Albizia adian hi olia (Schumach.) W. Wigh
0.00
1.37
0.00
0.41
Albizia e uginea (Guill. & Pe .) Ben h.
0.00
0.58
0.00
0.19
Albizia glabe ima (Schumach. & Thonn.) Ben h.
0.39
1.98
0.00
0.75
Albizia lau en ii (Schumach. & Thonn.) Ben h.
0.00
2.42
0.00
0.78
Alcho nea lo ibunda Müll. A g.
0.30
0.00
0.00
0.10
Als onia boonei De Wild.
0.31
0.00
0.00
0.10
Amphimas e ugineus Pie e ex Pelleg .
0.52
0.00
0.31
0.28
Angylocalyx pynae ii De Wild.
2.02
10.39
32.74
15.56
An hocleis a sp.
0.00
0.55
0.00
0.18
Wo ld Jou nal o Ad anced Resea ch and Re iews, 2025, 27(02), 2181-2191
2184
Ao an he cladan ha (K. Schum.) Some s
0.00
0.00
0.41
0.14
Ba e ia is ulosa Mas .
0.00
0.00
0.95
0.31
Blighia sp.
0.00
0.00
2.01
0.67
Blighia unijuga a (Hie n) Radlk.
0.30
0.00
0.00
0.10
Cana ium schwein u hii Engl.
0.31
1.26
1.86
1.19
Ca apa p oce a DC.
45.85
1.99
0.00
15.87
Cen oplacus glaucinus Pie e
1.31
0.00
0.00
0.43
Ch ysophyllum sp.
0.86
0.00
0.00
0.29
Cleis an hus inunda us J. Léona d
0.00
0.00
1.00
0.33
Cleis opholis pa ens (Ben h.) Engl. & Diels
0.01
0.00
0.79
0.27
Cleis opholis sp.
0.30
0.00
0.24
0.19
Coeloca yon p eussii Wa b.
8.29
3.75
3.75
5.12
Cola ballayi Co nu ex Heckel
0.00
0.00
4.40
1.49
Co ynan he pachyce as K. Schum.
0.00
0.00
0.32
0.10
Dac yodes bue ne i (Engl.) H.J. Lam
0.91
0.55
0.00
0.49
Dac yodes no mandii Aub é . & Pelleg .
0.00
0.00
3.14
1.20
Dac yodes sp.
1.96
0.60
0.33
0.97
Daniellia pynae ii De Wild.
0.41
1.77
0.00
0.70
Despla sia sp.
0.00
0.00
1.13
0.37
Dialium pachyphyllum Ha ms
2.44
41.61
5.57
16.11
Dialium sp.
1.01
0.00
3.04
1.37
Dichae an he a sp.
0.00
0.80
0.00
0.26
Dichos emma glaucescens Pie e
0.66
0.00
0.00
0.11
Diospy os c assi lo a Hie n
4.42
10.91
2.77
5.98
Diospy os dendo Hie n
2.33
0.00
0.00
0.77
Diospy os mannii Hie n
0.31
0.00
0.63
0.31
Diospy os sp.
0.30
0.00
0.95
0.42
D ype es occiden alis (Müll. A g.) Hu ch.
21.02
0.00
0.00
6.99
Duboscia mac oca pa Bocq.
0.00
0.00
3.86
1.37
En and oph agma angolense (Welw.) C. DC.
0.00
0.00
2.69
0.99
En and oph agma cylind icum (Sp ague) Sp ague
0.00
0.00
1.86
0.65
En and oph agma palus e S ane
18.91
0.58
0.00
6.46
E iocoelum mic ospe mum Gilg ex Radlk.
10.61
12.28
1.51
8.04
E y h ophleum sua eolens (Guill. & Pe .) B enan
0.00
0.00
0.37
0.12
Ga cinia punc a a Oli .
0.00
6.73
13.69
6.84
Ga cinia smea hmannii (Planch. & T iana) Oli .
8.39
0.00
0.00
2.79
Ga cinia sp.
2.70
6.15
2.46
3.72
Ga denia impe a is K. Schum.
0.00
3.46
0.00
1.07
Wo ld Jou nal o Ad anced Resea ch and Re iews, 2025, 27(02), 2181-2191
2185
Gilbe iodend on dewe ei (De Wild.) J. Léona d
0.00
0.00
49.78
17.65
G ewia oligoneu a Sp ague
0.63
0.00
0.00
0.21
G osse a mac an ha Pax
24.53
10.84
0.00
11.63
Guibou ia demeusei (Ha ms) J. Léona d
6.25
23.23
0.32
9.28
Hallea s ipulosa (DC.) Le oy
2.77
1.45
0.00
1.39
Heis e ia sp.
0.00
0.00
0.31
0.10
Inde sp.
2.33
9.96
4.14
5.38
I ingia gabonensis (Aub y-LeCom e ex O'Ro ke) Baill.
0.00
0.00
0.40
0.24
Klainedoxa gabonensis Pie e ex Engl.
0.00
11.96
9.26
6.93
Leplaea hompsonii (Sp ague & Hu ch.) E.J.M. Koenen & J. J. de Wilde
0.00
0.00
0.94
0.31
Lophi a ala a Banks ex C. F. Gae n.
0.00
32.37
18.39
16.46
Maca anga spinosa Müll. A g.
0.87
1.23
0.75
0.95
Maesopsis eminii Engl.
0.00
0.00
0.34
0.11
Mammea a icana Sabine
1.31
0.00
1.85
1.06
Manilka a ouilloyana Aub é . & Pelleg .
14.55
2.21
0.50
5.71
Manilka a obo a a (Sabine & G. Don) J. H. Hemsl.
4.85
0.00
0.33
1.72
Ma an hes sp.
0.31
0.00
0.00
0.10
Massula ia acumina a (G. Don) Bullock ex Hoyle
0.00
1.14
3.66
1.61
Milicia excelsa (Welw.) C.C. Be g
0.00
0.00
12.79
4.77
Monodo a my is ica (Gae n.) Dunal
0.00
4.18
1.32
1.82
Musanga cec opioides R. B .
0.00
0.00
0.97
0.35
Panda oleosa Pie e
0.00
1.62
5.45
2.36
Pa ina i excelsa Sabine
0.00
5.40
0.87
2.01
Pau idian ha sp.
0.00
0.00
0.86
0.30
Pen acle h a mac ophylla Ben h.
0.00
6.70
7.56
4.80
Pe e sian hus mac oca pum (P. Beau .) Liben
0.00
0.99
6.77
2.59
Pip adenias um a icanum (Hook. .) B enan
0.00
0.60
0.00
0.19
Plagios yles a icana (Müll. A g.) P ain
1.28
13.84
3.86
6.28
Pseudospondia mic oca pum (A. Rich.) Engl.
0.00
0.00
2.71
0.96
P e oca pus soyauxii Taub.
0.00
1.25
0.00
0.38
Pycnan hus angolensis (Welw.) Wa b.
0.00
3.28
4.64
2.66
Rhabdophyllum a noldianum (De Wild. & T. Du and) Tiegh.
0.00
6.51
0.05
2.15
Rhabdophyllum sp.
0.00
0.00
0.95
0.31
Rino ea sp.
0.32
0.66
1.92
0.97
S aud ia kame unensis Wa b.
0.00
5.48
13.48
6.33
S e culia agacan ha Lindl.
3.66
0.00
0.00
1.21
S ombosia g andi olia Hook. .
0.00
18.38
28.89
16.00
S ombosiopsis e and a Engl.
0.00
9.27
6.09
5.15
Wo ld Jou nal o Ad anced Resea ch and Re iews, 2025, 27(02), 2181-2191
2186
Symphonia globuli e a L. .
37.49
0.00
0.00
12.41
Synsepalum subco da um De Wild.
0.00
0.00
3.03
1.06
Syzygium s aud ii (Engl.) Mildb .
0.00
0.57
0.00
0.18
Te minalia supe pa Engl. & Diels
0.00
0.00
2.46
0.90
Tesmania sp.
0.00
0.00
0.78
0.27
Thomande sia sp.
0.00
0.00
0.65
0.22
T eculia a icana Decne.
0.53
0.00
0.00
0.18
T icalysia sp.
0.00
0.78
0.00
0.24
T ichilia gille ii De Wild.
0.00
0.00
0.41
0.14
T ichilia p ieu iana A. Juss.
0.00
4.04
0.00
1.22
T ichilia sp.
1.05
0.57
0.42
0.68
T ichilia welwi schii C. DC.
1.42
0.00
0.00
0.46
T ilepisium madagasca iensis DC.
0.00
0.57
0.00
0.34
Uapaca mole Pax
34.75
4.21
4.51
14.45
Vi ex welwi chii Gü ke
0.00
0.00
0.68
0.23
Xylopia ae hiopica (Dunal) A. Rich.
6.96
5.01
1.09
4.29
Xylopia hypolamp a Mildb .
0.00
1.95
3.00
1.67
Xylopia ubescens Oli .
16.37
0.00
0.00
5.43
Xylopia sp.
0.61
0.00
0.00
0.21
To al
300
300
300
300
In he PFF, Dialium pachyphyllum had he highes ecological impo ance alue. I was ollowed by Lophi a ala a,
Guibou ia demeusei, S ombosia g andi olia, Plagios yles a icana, E iocoelum mic ospe mum, Klainedoxa gabonensis,
Diospy os c assi lo a, G osse a mac an ha and Angylocalyx pynae ii (Table 2). The species o g ea es ecological
impo ance in he TFF we e, in descending o de : Gilbe iodend on dewe ei, Angylocalyx pynae ii, S ombosia
g andi olia, Lophi a ala a, Ga cinia punc a a, S aud ia kame unensis and Milicia excelsa. Fo he en i e swamp o es
s udied, Gilbe iodend on dewe ei, Lophi a ala a, Dialium pachyphyllum, S ombosia g andi olia, Ca apa p oce a,
Angylocalyx pynae ii, Symphonia globuli e a, Uapaca mole and G osse a mac an ha we e he mos ecologically
impo an species.
3.2. Fo es s and s uc u e
3.2.1. Ho izon al s uc u e
The a e age densi y is 390±9 s ems/ha o he Likouala swamp o es (no he n o he epublic o Congo). The h ee
acies s udied ha e mean densi ies o a ound 445±8, 373±15 and 351±13 espec i ely in he FF, PFF and TFF, ending
o dec ease signi ican ly om he FF o he TFF (Figu e 1).
Wo ld Jou nal o Ad anced Resea ch and Re iews, 2025, 27(02), 2181-2191
2187
Figu e 1 Spa ial a iabili y o ee densi y in he Likouala swamp o es
Basal a ea da a di e be ween he ansec s and hei cha ac e is ic acies s udied (Table 3). The a e age basal a ea o
he Bondzalé ansec is oughly equal o ha o he Ekolongouma ansec and highe han ha o he I anga ansec .
The mean basal a ea dec eases in wo di ec ions on he h ee acies s udied pe ansec : Bondzalé (FF<PFF<TFF),
Ekolongouma (FF<PFF<TFF) and I anga (FF>PFF>TFF). The Likouala swamp o es has an a e age basal a ea o
32.26±1.5 m2/ha.
Table 3 Basal a ea (m2/ha) o he di e en si es ( ansec s) s udied
Fo es ypes
Si es
Swamp Fo es
Bondzalé
Ekolongouma
I anga
FF
31.00±1.5
29.56±4.6
29.74±1.6
30.00±2.1
PFF
36.08±0.8
33.67±2.7
23.61±1.9
31.12±2.2
TFF
38.18±5.4
38.05±4.5
23.61±2.1
35.46±3.2
3.2.2. Ve ical s uc u e
O e all, he Likouala swamp o es has a minimum heigh o 10.05 m and a maximum heigh o 43.65 m, wi h an a e age
heigh o 22.69±5.43 m (Table 4).
Table 4 Minimum and maximum ee heigh s on he o es ypes s udied
Fo es ypes
Minimum heigh (m)
Maximum heigh (m)
Mean heigh (m)
FF
10.05
32.85
20.26±4.20
PFF
11.25
35.25
20.19±4.88
TFF
10.65
43.65
26.10±5.82
Maximum ee heigh and a e age canopy heigh inc ease om looded o es o e a i me o es .
3.2.3. Diame ic s uc u e
The diame ic dis ibu ion cu es o indi idual ees sampled in he h ee o es ypes o he Likouala swamp o es
a e in he shape o an in e ed J (Figu e 2).
Wo ld Jou nal o Ad anced Resea ch and Re iews, 2025, 27(02), 2181-2191
2188
Figu e 2 Diame ic dis ibu ion o ees in he h ee o es ypes o he Likouala swamp o es
4. Discussion
4.1. Ecological impo ance o ee species
A species has a high ecological impo ance when i s impo ance alue index is g ea e han o equal o 10 pe 300 [23].
This dominance is based on he combined alues o ela i e densi y, ela i e dominance and ela i e equency wi hin
he s and s udied [22]. The esul s o his s udy e ealed ha he numbe o dominan species ends o inc ease as one
mo es om e a i me o es o looded o es . In each o es ype o he Likouala swamp o es , species o e y high
ecological impo ance ep esen mo e han 56% o he species eco ded. Sciaphy e species, i.e. hose ha ole a e shade
[26], a e he bes ep esen ed in he h ee o es ypes. In he pea looded o es (FF), nine species o high ecological
impo ance make up a ound 75% o he 50 species eco ded. These sciaphy es, no ably Ca apa p oce a, Symphonia
globuli e a, G osse a mac an ha, D ype es occiden alis, Manilka a ouilloyana and E iocoelum mic ospe mum clea ly
domina e o e pionee species such as Uapaca mole and Xylopia ubescens. In he pe iodically looded o es (PFF), en
species wi h high alues o ecological impo ance accoun o 62% o he 51 species eco ded. As in he FF, shade-
ole an species, no ably Dialium pachyphyllum, Guibou ia demeusei, S ombosia g andi olia, Plagios yles a icana,
E iocoelum mic ospe mum, Diospy os c assi lo a, G osse a mac an ha and Angylocalyx pynae ii) a e dominan o e
pionee species such as Lophi a ala a and Klainedoxa gabonensis. As o e a i me o es (TFF), se en ecologically
impo an species accoun o 57% o he 68 species eco ded, wi h a ma ked p edominance o sciaphy es such as
Gilbe iodend on dewe ei, Angylocalyx pynae ii, S ombosia g andi olia, Ga cinia punc a a and S aud ia kame unensis.
Pionee species a e ew in numbe , being limi ed o Lophi a ala a and Milicia excelsa. The low ep esen a ion o pionee
species sugges s a g adual e olu ion o each o es ype in he Likouala swamp o es owa ds a ma u e s age,
cha ac e ised by a physiognomy domina ed by sciaphy e species. Al hough species wi h low ecological impo ance a e
a p io i y o conse a ion [27], a be e unde s anding o he ecology o species wi h high ecological impo ance
emains essen ial in o de o p opose app op ia e sus ainable managemen measu es.
4.2. S and s uc u e
The densi y ob ained in FF (445±8 s ems/ha) is sligh ly highe han ha ound by Lewis e al. [28] in he looded o es s
o Cen al A ica (428 s ems/ha) and A ica (426 s ems/ha). Lewis e al. [28] also men ion ha he numbe o s ems pe
hec a e inc eases om TFF o FF. This di e ence in densi y can be explained by he speci ic composi ion o each o es
ype and he capaci y o na u al egene a ion. This egene a ion capaci y is e lec ed in he high numbe o ees wi h
a diame e o less han 70 cm in he FF.
The a e age basal a ea ob ained in ou swamp o es (32.26±1.50 m2/ha) is wi hin he ange o alues es ima ed o
opical o es s (25.00 - 50.00 m2/ha) [16]. I is close o ha ound by Lewis e al. [28] in cen al A ica (30.00 m2/ha).
Ou basal a ea alue ob ained in he FF is highe han ha ound by Lewis e al. [28]. These di e ences be ween he
Wo ld Jou nal o Ad anced Resea ch and Re iews, 2025, 27(02), 2181-2191
2189
acies s udied and be ween ou esul s and hose ound in Cen al A ica may be linked o he pe cen age o la ge-
diame e ees and o he di e en species composi ion o he di e en o es ypes.
The esul s conce ning he e ical s uc u e o he looded o es a e close o hose ound by Gibe [2] in he Likouala
egion, al hough hese esul s conce ning he minimum heigh o he canopy (15.00 m) a e highe han hose ound
du ing he p esen s udy (10.05 m). This di e ence in minimum heigh can be explained by he leng h o he ansec
(9.00 km), which made i possible o a oid edge e ec s by sampling ees igh in o he looded o es domina ed by
Raphia lau en ii. In ac , ees g owing in looded o es domina ed by Raphia lau en ii end o be s un ed. This can be
explained by he di icul en i onmen al condi ions, which lead woody ees o se up adap a ion mechanisms [18]. The
maximum heigh o he canopy in ou looded o es (31.20 m) is highe han he 20.00 m ound by E a d [18] and
Be bede e al. [20] in he FF o he cen al basin. On he o he hand, i is close o he maximum s and heigh o 30.00 m
ound by Gibe [2] in he FF whe e En and oph agma palus e is p esen . The maximum canopy heigh s o he PFF
(35.25 m) and TFF (43.65 m) a e close o he alues o 30.00 m and 40.00 m epo ed by E a d [18] and Be bede e
al. [20] o he PFF and TTF ( espec i ely) in he cen al A ica. Ou ansec e eals a a dis ance o 9.00 km a educ ion
in he maximum canopy heigh o ou swamp o es s and o a ound 12 m, s a ing om FTF (43.65) o FF (31.20 m).
This esul is oughly equal o ha ound by Pascal [29] in a swamp o es in India (10.00 m). This educ ion in he
maximum heigh o he s and can be explained by he in luence o he adap i e cons ain s o which ee species a e
subjec when aced wi h a hyd omo phic en i onmen (FF). The la e does no allow hem o main ain good g ow h in
heigh , excep o ce ain ees such as En and oph agma palus e, Symphonia globuli e a and Manilka a ouilloyana.
A s udy o he diame ic s uc u e o he di e en o es ypes e ealed a egula dec ease in he numbe o ees wi h
each diame e class. This esul highligh s he exis ence o se e al sciaphy e (shade- ole an ) species on he h ee o es
ypes s udied [16]. The “in e ed J” dis ibu ions, ypical o undis u bed opical o es s [16], unde line he ac ha ou
swamp o es is no in he p ocess o eg ession. The s and on each o es ype is young. The numbe o ees wi h a
diame e g ea e han o equal o 70 cm, which ends o inc ease om he looded o es o he e a i me o es , e lec s
he basal a ea da a ound du ing his s udy.
5. Conclusion
The lo is ic and s uc u al cha ac e isa ion o he h ee o es ypes o he Likouala swamp o es was ca ied ou o e
a s udy a ea o 7.06 ha. The ecological unc ioning o he h ee o es ypes s udied is based on 7, 9 and 10 species wi h
high alues o ecological impo ance, espec i ely o he TFF, FF and PFF. The low ep esen a ion o pionee species
sugges s a g adual e olu ion o each o es ype in he Likouala swamp o es owa ds a ma u e s age, cha ac e ised by
a physiognomy domina ed by sciaphy e species. The densi y and basal a ea alues ob ained a e ypical o opical
ain o es s and di e signi ican ly be ween o es ypes. The minimum and maximum heigh s o ees on he di e en
acies s udied ended o inc ease om FF o TFF. Diame ic dis ibu ion cu es e ealed ha he Likouala swamp o es
ypes s udied a e undis u bed and composed o se e al sciaphilous species.
Compliance wi h e hical s anda ds
Acknowledgmen s
We hank he illages o Bondzalé, Ekolongouma and I anga, o hei assis ance du ing he ield da a collec ion pe iod.
Disclosu e o con lic o in e es
The au ho s decla e ha he e a e no con lic s o in e es .
S a emen o in o med consen
In o med consen was ob ained om all indi idual pa icipan s included in he s udy.
Re e ences
[1] de Wasseige C, Flynn J, Louppe D, Hiol F, Mayaux P. The o es s o he Congo Basin - S a e o he o es s 2013.
Wey ich, Belgium; 2014; 328 p.
[2] Gibe G. The Congolese o es mass: i s loca ion and a ious acies. BFT. 1984; 204: 3-19.
