Dados do Trabalho

TÍTULO

PREDICTING BIODIVERSITY LOSS IN ISLAND AND COUNTRYSIDE ECOSYSTEMS THROUGH TAXONOMIC AND FUNCTIONAL BIOGEOGRAPHY

Resumo

We investigate how variation in patch- and landscape-level habitat loss affects species richness and functional diversity of bat assemblages in two ecosystems differing in fragment-matrix contrast: a landbridge island system in Panama and a countryside ecosystem in the Brazilian Amazon. Bats were sampled on 11 islands and the adjacent mainland in Panama, and in eight forest fragments and continuous forest sites in Brazil. Species–area relationships (SAR) were assessed based on Chao1 species richness estimates, and functional–area relationships (FAR) were quantified using Chao1 functional diversity estimates measured as the total branch length of a functional tree. We found that in both study systems, functional diversity was less sensitive to habitat loss than species richness, in the sense that an equal reduction in habitat loss led to a disproportionately smaller loss of functional diversity compared to species richness. However, an inhospitable and static aquatic matrix resulted in more pronounced species loss with increasing loss of habitat compared to the countryside ecosystem. Moreover, we found that FAR based on trait sets reflecting “diet breadth” and “dispersal ability” varied according to spatial scale and fragment-matrix contrast of the landscape. Our findings highlight that species richness and functional diversity in island and countryside ecosystems scale fundamentally differently with habitat loss, and suggest that certain bat ecological functions, such as pollination and seed dispersal, are maintained among fragments even with the reduction in species richness. Our study provides novel insights that can guide future research in functional biogeography and has implications for the implementation of effective conservation strategies in insular and countryside landscapes.  

Palavras-chave

conservation biogeography, environmental filters, forest area loss, functional–area relationship, species–area relationship, tropical bats

Financiamento

FZF was supported by a fellowship from Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), CEVG by Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) and by INCT in Ecology, Evolution and Biodiversity Conservation (MCTIC/CNPq/FAPEG), AL-B by Fundação para a Ciência e a Tecnologia (FCT), RR by FCT and CFJM by German Academic Exchange Service (DAAD) and FCT (PTDC/BIA-BIC/111184/2009).