Biodiversité et services écosystémiques en forêts tropicales : le rôle des affectations des terres forestières dans la région du Dja, Cameroun

Abstract

In central Africa, tens of millions of people depend on tropical forests for their livelihoods. The biodiversity of these ecosystems is unique and provides important ecosystem services (ES), which can vary depending on management strategies. For this PhD thesis, we assessed biodiversity and ecosystem services in the Dja landscape in Cameroon forests classified into three forest land allocations use: a protected area, an FSC-certified logging concession and three community forests. First, we assessed the forest conservation value based on the species richness and composition of two taxonomic groups, mammals and dung beetles. The largest and most threatened species were detected in the protected area and in the most remote areas in the logging concession, which are better preserved from human influence. In contrast, the community forests seemed to be particularly lacking in fauna and degraded due to their proximity to roads and villages, but these cover much smaller areas and still have a closed canopy. Secondly, interviews identifying the perceptions of ES supply showed that provisioning and cultural services are the most important ES for local populations, in contrast to regulating services which were barely mentioned. Among the former, bushmeat was the only service for which the forest supply is not sufficient for local populations. Thirdly, combining interviews and field surveys, we quantified the use by local populations of eight provisioning and cultural ES. We found that firewood and timber are used sustainably by local populations, whereas bushmeat hunting and consumption exceed sustainability thresholds. Reconciling wildlife conservation, food security, and sustainable hunting practices is a major challenge in central Africa. To address this challenge it is crucial to include all stakeholders in sustainable forest management strategies, in order to identify the social levers that can underpin behavioural changes among forest users.