Butterfly Diversity in Relation to Human-Impact Gradient in Out-skirts of Kolkata,West Bengal,India

Anthropogenic activities may affect species diversity and community structure.Butterfly species diversity in relation to human-impact gradient was evaluated in the Baruipur subdivision,outskirts of Kolkata metropolis,West Bengal,India as a model geographic area.Four study sites situated in bird sanctuaries,rural,suburban and urban areas with different levels of anthropogenic disturbances were selected to assess the human impact on butterfly diversity.A total of 80 butterfly species were recorded during the entire study period with the sanctuary(with minimal anthropogenic disturbance)showing the highest species richness(73)followed by rural(62),suburban(54)and urban(36)study sites indicating a strong negative impact of anthropogenic disturbance on butterfly species diversity.Butterfly species diversity varied significantly among different habitats(p˂0.001).The relative abundance of butterflies also varied seasonally.It is apparent that the area under the present study is able to sustain diverse butterfly species provided natural habitats are protected from anthropogenic disturbances and steps are taken to increase urban greenery to support butterfly diversity and consequent ecosystem services.

Climate and land-use interactively shape butterfly diversity in tropical rainforest and savanna ecosystems of southwestern China

Human-induced habitat conversion and degradation,along with accelerating climatic change,have resulted in considerable global biodiversity loss.Nevertheless,how local ecological assemblages respond to the interplay between climate and land-use change remains poorly understood.Here,we examined the effects of climate and land-use interactions on butterfly diversity in different ecosystems of southwestern China.Specifically,we investigated variation in the alpha and beta diversities of butterflies in different landscapes along human-modified and climate gradients.We found that increasing land-use intensity not only caused a dramatic decrease in butterfly alpha diversity but also significantly simplified butterfly species composition in tropical rainforest and savanna ecosystems.These findings suggest that habitat modification by agricultural activities increases the importance of deterministic processes and leads to biotic homogenization.The land-use intensity model best explained species richness variation in the tropical rainforest,whereas the climate and land-use intensity interaction model best explained species richness variation in the savanna.These results indicate that climate modulates the effects of land-use intensity on butterfly alpha diversity in the savanna ecosystem.We also found that the response of species composition to climate varied between sites:specifically,species composition was strongly correlated with climatic distance in the tropical rainforest but not in the savanna.Taken together,our long-term butterfly monitoring data reveal that interactions between human-modified habitat change and climate change have shaped butterfly diversity in tropical rainforest and savanna.These findings also have important implications for biodiversity conservation under the current era of rapid human-induced habitat loss and climate change.