[en] Landscape Ecological Survey of the Bipindi-Akom II ... - ITTO

The vegetation of this community group are broad-leaved tropical ombrophilous swamp forests
and broad-leaved tropical ombrophilous alluvial forests (UNESCO, 1981). Due to the small scale
of Letouzey' Letouzey's s phytogeographic map, i.e. 1:500,000, I :500,000, the small areas covered by swamp vegetation
have not been accounted for individually. They appear as complexes with the surrounding forest
types.
6.4.6 Xylopia - Musanga community (IV)
The Xylopia - Musanga community is a young secondary forest. Differentiating species of this
community are Xylopia 'group 1', Fagara macrophylla, Palisota ambigua, Thaumantococcus
'group 1', Megaphrynium secundiflorum and Ancistrophyllum 'group 1'.
In general, the vegetation consists of three distinct strata: tree, shrub and herb layer. Often relics
of the undisturbed forest are presents. In general the external foliage cover of these emergents is
less than ten percent. The tree layer is open (40-50%) and is only 15-25 m high. Dominant growth
forms are evergreen broad-leaved trees and palms. The most common species are Musanga
cecropioides, Pycnanthus angolensis, Coelocaryum preussii, Funtumia elastica, Xylopia 'group
I', Tabernaemontana crassa, Rauvolfia macrophylla and Ricinodendron heudelotti. Other
frequently occurring species are Fagara macrophylla, Vitex grandifolia and Macaranga 'group
I'. The shrub layer is 2-7 m high and often merges into the tree layer. It is closed and infested with
thorny Iianas such as Ancistrophrynium secundiflorum and Haumania danckelmanniana. The trees
in this layer often have thorns, e.g. Fagara macrophylla. Stilt roots are abundant. Xylopia 'group
I " Alchornea floribunda, Anthonotha macrophylla, Megaphrynium secundiflorum and Ouratea
flava are the most common species. The herb layer is rather open and has an average height of 50
cm. Broad-leaved herbs tend to dominate. Characteristic species are Stylochiton zenkeri,
Thaumantococcus 'group I', Haumannia danckelmanniana, Palisotha ambigua, Rektophylium
'group I' and Stipularia africana.
This community is the typical fallow vegetation in shifting cultivation areas and is found near
villages and along the main access roads, throughout the TCP area. To a lesser extent it is found
in logged-over forests. It is induced by human activity and appears to be rather insensitive to soil
, and landform variation. The Xylopia - Musanga community forms a transitional stage between the
Macaranga - Chromolaena community (V) and old secondary forest types (IIa, llb, IIc and Ill; all
p.p.). It develops some five years after fallow.
The vegetation can be typified as evergreen broad-leaved woodland in the UNESCO classification
of vegetation (UNESCO, 1981). The distribution of the Xylopia - Musanga community within the
TCP research area coincides with Letouzey's type n° 251, i.e. remnants of strongly degraded
evergreen forests. Physiognomy and species composition is also comparable although some
elements of Letouzey's 'strongly degraded remnants of semi-deciduous forest' (type nO 169) are
also present.
6.4.7 Macaranga - Chromolaena community (V)
The Macaranga - Chromolaena community forms thickets on recently abandoned fields and in
cacao plantations. The differentiating species of this community are Macaranga 'group I',
Chromolaena odorata, Albyzia zygia, Costus violaceus, Milicia excelsa, Rauvolfia vomitoria and
Ceiba pentandra. In addition, some cultivated species are still present, e.g. Trifolium 'species I'
(groundnut), Manihot esculenta (cassava), Colocasia 'species l' (coco-yam) and Musa 'species
I' (plantain).
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