Long-term ecological impacts of harvesting non-timber forest products on tree species diversity at the periphery of Mbam and Djerem National Park, Cameroon

摘要

Non-timber forest products (NTFPs) strongly contribute to livelihood security of forest-adjacent communities. This study examined the impacts of their harvesting on tree species diversity at the periphery of Mbam and Djerem National Park (Cameroon). Tree species diversity, with diameter at breast height (dbh) ≥ 10 cm, was analyzed in small plots (10 × 100 m) along seven 1-ha transects. Species diversity and floristic composition of undisturbed and disturbed sites were compared in order to obtain an indication of the impact of harvesting NTFPs. A total of 1294 stems was recorded, representing 99 species, 96 genera and 36 families. Shannon diversity index values were highest in undisturbed sites (H’ > 3.5 bits), and lower in disturbed sites (H’ < 3.5 bits). Analysis of variance showed significant differences in mean diversity measures between the two sites (p = 0.047). Mean number of stems cut within the disturbed sites was 15.5 ± 5.5 stems ha-1. The park’s region was found to be rich in Euphorbiaceae, Caesalpiniaceae and Annonaceae. The survey highlighted the effectiveness of harvesting NTFPs in the region and its impacts on tree species diversity. Efforts should be made more in order to improve the protection of the park, and the development of a suitable regional conservation of biodiversity.