Perez-Torres, J. | Search bioRxiv

bioRxiv2019

Responses of bats to landscape transformation in an Andean agricultural landscape

The current debate on the future of biodiversity gives rise to the need to integrate agricultural landscapes into conservation strategies. Bats are an important component of vertebrate diversity in many terrestrial landscapes where they provide invaluable and important ecosystem services to human societies such as insect pest control, pollination and seed dispersal. Here we study bat diversity and abundance in three landscapes representing a transformational gradient (continuous forests, forest fragments and crops) in an Andean agricultural scenario known as Colombias "Coffee Cultural Landscape". We captured 1146 bats from 32 species and 4 families. The bat diversity and abundance in this landscape were high, especially for frugivorous bats, but there were no differences among the three transformational landscapes. However, some species were captured differentially between landscapes, suggesting that these landscapes have characteristics that influence the relative abundance of bats. Additionally, body weight and sex affect the abundance of some species in forest fragments and crops.

ecology↗

bioRxiv2019

Bat-fruit networks structure resist habitat modification but species roles change in the most transformed habitats

Species do not function as isolated entities, rather they are organized in complex networks of interactions. These networks develop the ecological processes that provide ecosystem services for human societies. Understanding the causes and consequences of changes in ecological networks due to landscape modification would allow us to understand the consequences of ecological processes. However, there is still theoretical controversy and few empirical data on the effects of network characteristics on the loss of natural environments. We investigate how bat-fruit networks respond to three landscapes representing the gradient of modification from pre-montane forest to a heterogeneous agricultural landscape in the Colombian Andes (continuous forests, forest fragments, and crops). We found that forest contained smaller bat-fruit networks than forest fragments and crops. Modified landscapes had similar ecological network structures to forest (nestedness and modularity), but crops contained less specialized networks compared to forests and fragments and the species role in these habitats change. The networks in the rural coffee landscape maintain their structure in the different transformation scenarios, indicating that seed dispersal services are maintained even in the most transformed scenarios. This could be related to the high heterogeneity present in this rural landscape. Although the number of species does not decrease due to transformations, species change their roles in the most transformed habitats. This result sheds light on the way that biodiversity responds to anthropogenic transformations, showing higher stability than theoretically predicted.

ecology↗