Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

In search of the forest in Côte d'Ivoire, Parts 1 & 2.

Abstract

Until 1935, tracts of virgin forest could still be seen when travelling along the roads of Côte d'Ivoire. Since then, with the unbridled expansion of coffee and rain-fed rice crops, runaway forest clearing has been the rule. Farmers fleeing the depredations of the agouti, or of parasitic family members, move away to clear more distant forests. By 1957, an expedition was needed to search for primary forests. A new road would destroy a forest within ten years, and loggers would only come through once. With the disappearance of Africa's dense humid forests, the dry season in its Sudano-Sahelian regions has grown longer. It is also important to map the areas of primary forest before they disappear altogether. The study presented here aimed to classify the vegetation of Côte d'Ivoire's forests on the basis of 12 transects in dense humid forests, since the phytosociological approach is not robust enough to produce such an analysis. Two groups characterised by specific botanical families were identified: "dense humid semi-deciduous forests with Malvaceae and Ulmaceae", and "dense humid forests with evergreen leguminous species". However, some species with high dispersal potential, which are abundant in secondary forests, especially Triplochiton and Terminalia, do not fit into this classification. The fact that the areas of distribution of certain species are discontinuous may be accounted for by seed dispersal, but also by the palaeohistory of the flora and climate. Similarly, the ecological area concept cannot be applied to rare or locally endemic species. This study also discusses several indigenous invasive species, such as Scaphopetalum amoemum and Chidlowia sanguinea, whose growth prevents forest regeneration. Finally, it discusses the presence within humid forests of patches of savannah, which are always of edaphic and not anthropic origin.