Something is missing at the bottom: Importance of coastal rainforests for conservation of trees, birds and butterflies in the Mount Cameroon area
Abstract
The Guinean Forest of West Africa is a biodiversity hot spot and comprises the Mount Cameroon National Park (MCNP) with its high diversity of endemic animal and plant species The highest richness of plant, reptile, mammal or bird species is found in low elevation forests, but MCNP protects habitats only above ca. 300 m a.s.l., because primary coastal forests are not included within its area. The only largest remnant of littoral forest in the whole region is the Bimbia Bonadikombo community forest (BB forest) lying approximately 15-20 km apart.
By its 3,735 ha, it covers diverse habitats, and is structurally exceptionally heterogeneous. To our knowledge, its biodiversity is rather poorly known and any regional comparison is completely missing.
The insufficient knowledge contrasts with the fact that these lowland habitats are highly threatened by destruction and they hosted the most plant species currently considered as possibly extinct. Therefore, we asked (i) whether the high diversity of vegetation types in BB forest corresponds with high species richness of trees, birds and fruit-feeding butterflies.
At least in lowland rainforests, vegetation structure, rather than tree species richness, seems to be important for both birds and fruit-feeding butterflies. Therefore, we do not expect a close match in species richness patterns for the three taxa. (ii) Whether there is a match in total vegetation volume and the detected abundance of birds and fruit-feeding butterflies as resource availability is expected to increase with vegetation biomass. (iii) What proportion of tree, bird and fruit-feeding butterfly species is unique to BB forest.
To answer these questions, we compared the biodiversity of the three groups in BB forest with two lowland localities within MCNP.