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

Climbers such as Haumania danckelmanniana and Ancistrophyllium secundijlorum are frequently
found. Treculia obovoides, Scorodophloeus zenkeri, Baphia lepitobotryx, Garcinia lucida,
Garcinia mannii, Mammea africana and Drypetes 'group I '. 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° 233 and partly with
n° 228 of the phytogeographic map of Letouzey (1985, see Figure 6.1). Structurally, it resembles
Letouzey's Forets submontagnardes (nO 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 (nOS 160 and 161). Also
many representatives of the Atlantic Biafran forest with Caesalpiniaceae (n° 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
ofMt Cameroon (4095 m asl) in the South-West Province ofCameroon.
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 as!.. 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 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.
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