Bipindi akom II lolodorf region, southwest



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Hymenostegia afzelii 

IV 
I r . . . 
Podococcus barteri  

III 
I + I I . 
Crotonogyne preussii 

II 
. r . . . 
Treculia obovoidea 

III 

. + I + 
Calpocalyx `group 1' 
II 


r .  . . 
Ptychop. petiolatum 
III 
IV 
III 
III 
+ II I 
Sorindeia `species 1' 
II 
II 
II 
II 
. + . 
Polyalthia suaveolens 

IV 
IV 
IV 
II I  . 
Grossera `group 1' 
II 
IV 
IV 
IV 
I III 

Scaphopetalum blackii 
II 
IV 
IV 
III 
II + I 
Plagiostyles africana 
II 
IV 
IV 
IV 
III I  + 
Dialium `group 1' 
II 
III 
IV 
IV 
. II 

Diospyros bipindensis 

II 
II 
II 
. + . 
Carpolobia `group 1' 

II 
II 
+ .  + I 
Erythrop. ivorense 

II 
III 
+ .  + . 
Grewia coriacea 


II 
r + I . 
Saccoglottis gabonensis 



r + + . 
Calpocalyx dinklagei 


III 
III 
I I + 
Rinorea kamerunensis  
II 

III 
IV 
+ I  . 
Diospyros suaveolens  

II 

IV 
III I  + 
Dracaena `group 1' 



II 
I . . 
Picralina nitida  



II 
. . . 
Strombosia pustulata  

II 
IV 
III 
II 
. . 
Halopegia `group 1' 
III 
IV 
IV 
III 
IV 
. . 
Santiria trimera  
III 
III 
III 
II 
II 
+ . 
Calamus deërratus 
III 
IV 
IV 
III 
III 
III 

Palisota mannii  
III 
IV 
IV 
II 
IV 
II 

Strombosia `group 1' 
III 
IV 
II 
III 
III 
II 

Scaphopetalum thonneri  
II 
IV 
III 
II 
II 


Uapaca guineensis 
III 
IV 
III 
II 
III 
II 
II 

 
 
62
 
Plant 
communities 
 
Differentiating 
species: 
 
 
 

 
Maranthes - 
Anisophyllea 
community
 
 
IIa
 
 
Podococcus - 
Polyalthia 
community
 
 
IIb
 
 
Strombosia 
- Polyalthia 
community
 
 
IIc
 
 
Diospyros - 
Polyalthia 
community
 
 
III
 
 
Carapa -
Mitragyna 
community
 
 
IV
 
 
Xylopia- 
Musanga 
community 
 
V
 
 
Macaranga-  
Chromolaena 
community 
 
 
 
 
 
 
Coelocaryon preussii  
III 
III 
IV 


IV 
II 
Haumania danckelm. 

IV 
IV 

III 

III 
Pycnanthus angolensis 

IV 
II 
IV 
III 
IV 
III 
Cercestis ivorensis  

II 
II 
III 
III 
III 

Lophira alata 


II 
II 
II 
II 
III 
Leea guineensis 




II 

II 
Elaeis guineensis 




III 
II 
III 
 
 
 
 
 
 
 
 
Mitragyna stipulosa  
 
 
 
 
 
 
 
Carapa `species 1' 
 




III 
. . 
Trichillia heudelotii 




III 
I I 
Xylopia `group 1' 


II 

II 
IV 
II 
Fagara macrophylla  

II 
II 

II 
IV 
III 
Thaumantoc. `group 1' 





IV 
II 
Eribroma `group 1' 



III 

II 
III 
Terminalia superba  



II 

II 

Myrianthus arboreus  



II 

II 

Musanga cecropioides 




II 
IV 
IV 
Funtumia elastica 





III 
III 
Rauvolfia macrophylla 





II 
II 
Macaranga `group 1' 





II 
IV 
Chromolaena odorata  






IV 
Milicia excelsa 






III 
Rauvolfia vomitoria 






III 
Ceiba pentandra 






III 
Trifolium `species 1'  






(III) 
Anchom. `species 1' 






III 
Manihot esculenta  






(III) 
Frequency classes: . = absent; r = occurring once; + = present in 1-9% of the relevés; I = 10-19%; II = 20-39%; III = 40-59%; IV = 60-
79% and V = 80-100% () = cultivated.  
 
 
6.4 PLANT COMMUNITIES  
 
In this section the floristic composition, the physiognomy and the distribution of the seven plant 
communities are described. A tentative comparison with the vegetation types described by 
Letouzey (1968, 1985) and UNESCO (1981), and an ecological interpretation is included.  
 
6.4.1 Maranthes - Anisophyllea community (I)  
The  Maranthes-Anisophyllea community includes submontane primary and old secondary 
forests; its distribution within the TCP research area is restricted to hill and mountain tops 
surpassing 700 m asl. Differentiating species of this community are Drypetes `group 1', 
Anisophyllea polyneura,  Maranthes glabra, Scorodophloeus zenkeri, Gambeya `group 1'  Cola 
attiensis, Garcinia lucida and Diospyros hoyleana. 
 
In general, the physiognomy of this forest is characterized by the absence of emergents.  
Three structural layers can be distinguished. The tree layer forms an irregular canopy at a height 

 
 
63
of 15-20 m, occasionally reaching 35 m, with an external foliage cover of 70-80 %. The canopy 
is often climber infested and the presence of epiphytic mosses is characteristic. The broad-leaved 
trees, probable both evergreen and deciduous,  are branched at low heights and may have a 
crooked form. Stilt roots are common. Scorodophloeus zenkeri, Carapa `group 1', 
Monopethalanthus spp., Uapaca guineensis, Santira trimera, Allanblackia kisonghi, 
Anisophyllea polyneura, Baphia lepitobotryx, Coelycaryon preussi, Maranthes glabra and 
Tetraberlinia bifoliata are relatively common in the canopy. In some localities palms (Raphia 
`species 1') are present. The shrub layer (3-7 m), sometimes replacing the tree layer as canopy, 
varies from closed to very open. The shrub layer is mainly composed of saplings of forest trees. 
Only a few shrub species are present. Climbers such as Haumania danckelmanniana and 
Ancistrophyllium secundiflorum are frequently found. Treculia obovoides, Scorodophloeus 
zenkeri, Baphia lepitobotryx, Garcinia lucida, Garcinia mannii, Mammea africana and Drypetes 
`group 1'. are the most common species of the shrub layer. The herb layer is closed and may 
reach a height of one meter. This layer is dominated either by seedlings of forest trees or by 
herbs. Diospyros hoyleana, Scaphopetalum thonneri, Halopegia spp, Mapania amplivaginata 
and Palisotha mannii are frequently found. 
 
The forests of this type appear to be highly dynamic. Many traces of uprooted and broken trees 
are found. The gaps thus created are often infested by climbers that may reach down to the herb 
layer. Pioneer species like Musanga cecropioides are found in the larger gaps. Possible 
explanations for the dynamic nature of this vegetation are exposure to wind and instable steep 
slopes, often with rock outcrops. 
 
The submontane forest of the Maranthes - Anisophyllea community covers major parts of the 
Bingalanda mountain range in the southeastern part of the TCP area. The predominating 
landforms are mountains and isolated hills. The soils of these areas belong to the Nyangong type, 
i.e. very clayey soils with 40 to 80% clay in the B horizon. 
 
The structure of this forest type resembles `cloud forests'. As the elevation surpasses the average 
height of the cloud layer,  the vegetation is regularly engulfed in mist and drizzle (Hommel, 
1985). A characteristic growth form of such forests is beard moss. In the UNESCO classification 
of vegetation (1981), this vegetation can be typified as Tropical ombrophilous submontane forest.  
 
The distribution of this community coincides with the forest types n

117, n
o
 233 and partly with 
n
o
 228 of the phytogeographic map of Letouzey (1985, see Figure 6.1). Structurally, it resembles 
Letouzey's Forêts submontagnardes (n
o
 117) although species composition is distinctly different. 
Quite a number of species characteristic for the Maranthes - Anisophyllea community are typical 
for Letouzey's Semi-deciduous forest with Sterculiaceae and Ulmaceae (n
os
 160 and 161). Also 
many representatives of the Atlantic Biafran forest with Caesalpiniaceae (n
o
 228) are found. The 
Maranthes - Anisophyllea community apparently is a transitional vegetation between the moist 
Atlantic forest zone and the drier Guineo-Congolian semi-deciduous forest zone.  
 
Mbatchou (1995) studied the vegetation of the proposed Etinde Rainforest reserve on the slopes 
of Mt Cameroon (4095 m asl) in the South-West Province of Cameroon.  The submontane forest 
described by Mbatchou is divided in closed canopy submontane forest, discontinuous canopy 
submontane forest and submontane scrub. It is found between 800 and 1,700 m asl.. The 
submontane forests appears to be the transition between the lowland forest and the lower 
montane forest, and the species composition is a mixture of Guineo-Congolian and afromontane  
species. In structure and floristic composition, the Maranthes-Anisophyllea community 

 
 
64
resembles the closed canopy submontane forest of Mount Cameroon, although it is found in 
the TCP research area at much lower altitudes. The `telescope-effect', i.e. the vegetation of 
the highest summits in a given area more or less imitates the physiognomy and species 
composition of forest types generally bound to far higher altitudes elsewhere (Hommel, 
1987), could possibly be an explanation for the difference in altitude range.    
 
6.4.2 Podococcus - Polyalthia community (IIa)  
The Podococcus - Polyalthia community is a primary and old secondary lowland forest type; it is 
found at altitudes between 500 and 700 m asl. Differentiating species are Hymenostegia afzeilii, 
Podococcus barteri, Crotonogyne preussii, Tabernaemontana `species 1', Culcasia dinklagei, 
Duboscia macrocarpa and Petersianthus africana. 
 
At least four principal strata characterize the physiognomy of the Podococcus - Polyalthia 
community, although their boundaries are often difficult to establish. Large trees, often 
surpassing 55 meters in height, form the open (20 -30% cover) emergent layer. Klainedoxa 
microphylla and Monopethalanthus spp. frequently dominate this stratum. The tree layer forms a 
canopy at 25 to 40 meters. The external foliage coverage is 60-80 %. Large trees are the most 
common growth form and lianas appear to be restricted to the canopy and larger gaps. In general 
the trees have a smooth bark and only few have buttresses surpassing one meter in height. The 
most common species are Pycnanthus angolensis, Uapaca guineensis, Strombosia `group 1', 
Dichostemma glaucescens, Plagiostyles africana, Santira trimera, Alstonia congensis, 
Hymenostegia afzeilii, Desbordensia glaucescens and Scyphocephalium mannii. The shrub layer 
is relatively open, covering 40-60% and between two and ten meters high. Shrubs and saplings of 
forest trees are most common. Palms (Raphia `species 1' and Podococcus barteri) are frequently 
present but never dominate. Frequently found species of  the shrub layer are Ptycopetalum 
petiolanum, Polyalthia suaveolens, Scaphopetalum thonneri, Scaphopetalum blackii, 
Plagiostyles africana, Voacanga `group 1', Dialium `group 1', Coffea `group 1' and Grossera 
`group 1'. The herb layer is relatively open, covering 40-50%, and often low. Broad leaved herbs, 
seedlings of trees, palms and lianas are the major components. Frequently occurring species 
include Haumania danckelmannia, Palisota mannii, Halopegia `group 1', Calamus deëratus, 
Scaphopetalum thonneri, Rektophyllium `group 1', Cercestis ivorensis, Trachyprhrynium 
braunianum and Podococcus barteri.       
 
The Podococcus - Polyalthia community is found at altitudes between 500 and 700 m asl. It is 
found mainly in the southeastern zone of the TCP research area covering the slopes of the 
Bingalanda mountain range. The soils are mostly of the Nyangong type, i.e. very clayey soils with 
40 to 80% clay in the B horizon. Land forms encountered are, in descending order of importance: 
hilly uplands, complexes of hills, rolling uplands and isolated hills.  
 
According to the UNESCO classification (1981) this community is a Tropical ombrophilous 
lowland forest. The distribution of Podococcus - Polyalthia community in the TCP area coincides 
with the eastern part of Letouzey's Atlantic Biafran forest with Caesalpiniaceae (N
o
 228) of which 
the physiognomy and species composition indeed resemble the Podococcus - Polyalthia 
community.  
 
 

 
 
65
6.4.3 Strombosia - Polyalthia community (IIb)  
The primary and old secondary lowland forest of the Strombosia - Polyalthia community is found 
between 350 and 500 m asl. On the basis of the present vegetation survey only two (weakly) 
differentiating species have been identified, i.e. Grewia coriacea  and Saccoglottis gabonensis. 
The community is intermediate in both altitude and floristic composition between the two other 
primary to old secondary lowland forest communities: the Podococcus - Polyalthia community 
(IIa) and the Diospyros - Polyalthia community (IIc). 
 
The physiognomy of the Strombosia - Polyalthia community is similar to that of the Podococcus 
- Polyalthia community. The complex structure of the forest has four principal strata, including 
an emergent layer, a tree layer, a shrub layer and a herb layer. The height of the different strata 
varies and the boundaries are often difficult to establish. The emergent layer is open (external 
foliage cover < 20%) and reaches a height of 45-55 meters. The floristic composition is 
heterogeneous although Erythrophleum ivorensis appears to be the most common species. The 
external foliage cover of the tree layer is generally 60 - 70 %. The tree layer is found at the height 
of 25 to 35 meters. Broad-leaved evergreen trees are the dominant growth form  Lianas are 
relatively rare and no palms have been observed. The most common species are Plagiostyles 
africana, Coula edulis, Staudtia kamerunensis, Treculia obovoides, Coelecaryon preussii, 
Polyalthia suaveolens, Strombosia pistulata and Erythrophleum ivorensis. The shrub layer is 
dense (70-80%) and variable in height. In general it reaches from three to eight meters. It consists 
mainly of saplings of trees and shrubs. Lianas are scarce. The floristic composition of the shrub 
layer is heterogenous. The most frequently observed species are Treculia obovoides, 
Scaphopetaleum blackii, Ptycopetalum petiolanum, Carapa `group 1', Dialium `group 1', 
Grossera `group 1', Polyalthia suaveolens, Strombosia pistulata, Coelocaryon preussii, Staudtia 
kamerunensis and Calpocalyx dinklagei. The herb layer is relatively open (40%) and is in general 
0.4 to 0.7 meters high. Broad leaved herbs (e.g. Rektophyllium  `group 1', Palisota mannii, 
Halopegia `group 1', Cercestis ivorensis, Stylochiton zenkeri), seedlings of shrubs and trees (e.g. 
Pentaclethra macrophylla, Treculia obovoides, Dialium `group 1', Scaphopetaleum blackii, 
Scaphopetalum thonneri) and thorny lianas (e.g. Calamus deëratus, Haumannia 
danckelmanniana) are the most important components. 
 
The Strombosia - Polyalthia community is found in the central part of the TCP area forming a 
band of 10 to 15 km wide with a general southwest to northeast direction. The altitude range is 
350 to 500 m asl. Rolling and hilly uplands are the most important land forms in this zone. The 
soils are classified as `Ebom', i.e. clayey soils with 30 to 60% clay in the B horizon. 
 
According to the UNESCO classification (1981) this community is a tropical ombrophilous 
lowland forest. The distribution of the Strombosia - Polyalthia community is strictly confined to 
Letouzey's Atlantic Biafran forest with Caesalpiniaceae (n
o
 228, 1985, see Figure 6.1). 
Letouzey's description of the physiognomy and floristic composition of the Atlantic Biafran 
forest with Caesalpiniaceae corresponds with the Strombosia - Polyalthia community. 
 
6.4.4 Diospyros - Polyalthia community (IIc)  
The Diospyros - Polyalthia community is a primary to old secondary forest of altitudes below 
350 m asl. Differentiating species of this community are Diospyros suaveolens, Draceana `group 
1' and Picralima nitida.  
 
The physiognomy of the vegetation again is very similar to the structure of the other two 
communities of the Polyalthia community group. The forest structure is characterized by four 

 
 
66
principal strata. The emergent stratum is very irregular and its coverage varies between 0 and 
30%. The average height of this layer is 45 meters. Among the most common species are 
Desbordensia glaucescens, Klainendoxa gabonensis and Distamonanthus benthamianus. The 
tree layer is dense (70-80%) and is, in general, 20 to 35 meters in height. Trees are the sole 
important growth form in the canopy, except for the numerous gaps which are infested with 
thorny lianas. The most frequently occurring species of the tree layer are Plagiostyles africana, 
Coelocaryon preussii, Staudtia kamerunensis, Pycnanthus angolensis, Desbordensia 
glaucescens, Eribroma `group 1', Hylodendron `group 1' and Distamonanthus benthamianus. 
The shrub layer is relatively open where the canopy is closed, but can be very dense in the 
vicinity of gaps. Its height is variable but generally ranges from three to eight meters. Shrubs, 
small trees and saplings are the most important components. The most common species are 
Rinorea kamerunensis, Diospyros suaveolens, Calpocalyx dinklagei, Scaphopetaleum blackii, 
Anthonotha macrophylla, Grossera `group 1', Ptycopetaleum petiolanum, Polyalthia 
suaveolens and Tabernaemontana crassa. The herb layer is relatively open (40%), again with 
the exception of gaps where it is very dense. The average height is 0.5 meters and it consists of 
broad leaved herbs, lianas, ferns, grasses and tree seedlings. Most common species in the herb 
layer are Haumannia danckelmanniana, Rektophyllium `group 1', Gauduella spp., Cercestis 
ivorensis, Stylochiton zenkeri and Palisota ambigua. 
 
The Diospyros - Polyalthia community is found at low altitudes (< 350 m asl) in the northwest 
of the TCP area. The most important land forms are dissected plains, rolling uplands and hilly 
uplands. The soils in these regions are classified as `Ebimimbang' type, i.e. moderately well 
drained soils with  sandy top soils and less than 40% clay in the sub soil.  
The dissected plains in the northwest are relatively intensively used for shifting cultivation 
practices. Moreover, the area has been repeatedly logged. As a result the vegetation in this area 
is a mosaic of agricultural fields and more or less secondary forest and only small patches of 
relatively undisturbed forest of the Diospyros - Polyalthia community. 
 
According to the UNESCO classification (1981) this community is a tropical ombrophilous 
lowland forest. The distribution of the Diospyros - Polyalthia community within the TCP area 
includes the area designated by Letouzey (1985, see Figure 6.1) for the Biafran Atlantic forest 
rich in Caesalpiniaceae (n
o
 228) and Biafran Atlantic forest with Caesalpiniaceae still 
abundant (n
o
 231). Although the physiognomy is similar, the species composition of the tree 
and shrub layer of the Diospyros - Polyalthia community is quite different from the two 
Letouzey types. In fact, none of the Letouzey forest types is similar to this community neither 
in physiognomy nor in species composition. A possible explanation could be that the floristic 
composition of the forest has changed quite recently due to repetitive logging operations, while 
Letouzey bases his classification on more or less primary vegetation.  
 
6.4.5 Carapa - Mitragyna community (III)  
The  Carapa - Mitragyna community is a swamp forest. Differentiating species for this 
community are Mitragyna stipulosa, Carapa `species 1', Trichillia heudelotii, Diospyros preussii 
Cyathea `species 1' and Curcuma longa. 
 
The Carapa - Mitragyna community has three principal structural layers. The tree layer forms an 
open (60% cover) canopy at 35-40 m. Lianas like Ancistrophrynium secundiflorum, Haumania  
danckelmaniana and Calamus deëratus are abundant. The trees are often stilt rooted, crooked and 
branching at low heights. Mosses and epiphytes are found all along the stems. Common species of the 
tree layer are Coelycaryon preussi, Mitragyna stipulosa, Strombosia `group 1',Uapaca guineensis, 
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