Data from: Predicting biodiversity loss in island and countryside ecosystems through the lens of taxonomic and functional biogeography

We investigate how variation in patch area and forest cover quantified for
three different spatial scales (buffer size of 500, 1500 and 3000 m
radius) 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 nearby continuous
forest in Brazil. Species–area relationships (SAR) were assessed based on
Chao1 species richness estimates, and functional diversity–area
relationships (FAR) were quantified using Chao1 functional diversity
estimates measured as the total branch length of a trait dendrogram. FARs
were calculated using three trait sets: considering five species
functional traits (FARALL), and trait subsets reflecting “diet breadth”
(FARDIET) and “dispersal ability” (FARDISPERSAL). We found that in both
study systems, FARALL was less sensitive to habitat loss than SAR, in the
sense that an equal reduction in habitat loss led to a disproportionately
smaller loss of functional diversity compared to species richness.
However, the inhospitable and static aquatic matrix in the island
ecosystem resulted in more pronounced species loss with increasing loss of
habitat compared to the countryside ecosystem. Moreover, while we found a
significant FARDISPERSAL for the island ecosystem in relation to forest
cover within 500 m landscape buffers, FARDIET and FARDISPERSAL were not
significant for the countryside ecosystem. Our findings highlight that
species richness and functional diversity in island and countryside
ecosystems scale fundamentally differently with habitat loss, and suggest
that key bat ecological functions, such as pollination, seed dispersal,
and arthropod suppression, may be maintained in fragments despite a
reduction in species richness. Our study reinforces the importance of
increasing habitat availability for decreasing the chances of losing
species richness in smaller fragments.