Browsing by Subject "habitat change"

Land-use change stands behind the current biodiversity crisis and all it entails in terms of ecosystem services. Guinea-Bissau, in West Africa, is originally characterized by a forest- savanna mosaic biome. However, while savannas have long been planted with rice, both rice paddies and forest remnants are now being converted into cashew monocultures – the only cash crop in the country – at unprecedented rates. The ecological impact of such rapid change is largely unknown. To help fill this gap, we examined how three diversity metrics – rarefied species richness, abundance and composition – varied across forest remnants, cashew orchards and rice paddies for amphibians and reptiles in northern Guinea-Bissau. To do so, visual encounter surveys were carried across 21 sampling sites, seven of each habitat type. A total of 703 amphibian and 266 reptile encounters was recorded from nine and 14 taxa, respectively. The results show class-specific responses to habitat type. Amphibians’ diversity in forest remnants and cashew orchards was similar across all metrics, but rice paddies had a higher abundance and unique composition compared to forest remnants. Reptiles’ abundance was highest in cashew orchards and this habitat had a distinct composition, when compared to forest remnants. Rice paddies sustained both lower reptile richness and abundance. Overall, our results are not in agreement with the expected detrimental impacts of cashew expansion, which might be due to the still high heterogeneity of habitat types within the landscape. Rice paddies proved particularly important for amphibians, and for open-habitat reptiles, boosting overall species diversity. In face of the eminent habitat conversion, maintaining heterogeneous landscapes, including the persistence of both forest remnants and rice paddies, will allow minimizing biodiversity loss in West Africa.