Erosion of phylogenetic diversity in Neotropical bat assemblages: findings from a whole-ecosystem fragmentation experiment

Abstract

The traditional focus on taxonomic diversity metrics for investigating species responses to habitat loss and fragmentation has limited our understanding of how biodiversity is impacted by habitat modification. This is particularly true for taxonomic groups such as bats which exhibit species-specific responses. Here, we investigate phylogenetic alpha and beta diversity of Neotropical bat assemblages across two environmental gradients, one in habitat quality and one in habitat amount. We surveyed bats in 39 sites located across a whole-ecosystem fragmentation experiment in the Brazilian Amazon, representing a gradient of habitat quality (interior-edge-matrix, hereafter IEM) in both continuous forest and forest fragments of different sizes (1, 10, and 100 ha; forest size gradient). For each habitat category, we quantified alpha and beta phylogenetic diversity, then used linear mixedeffects models and cluster analysis to explore how forest area and IEM gradient affect phylogenetic diversity. We found that the secondary forest matrix harboured significantly lower total evolutionary history compared to the fragment interiors, especially the matrix near the 1 ha fragments, containing bat assemblages with more closely related species. Forest fragments ≥ 10 ha had levels of phylogenetic richness similar to continuous forest, suggesting that large fragments retain considerable levels of evolutionary history. The edge and matrix adjacent to large fragments tend to have closely related lineages nonetheless, suggesting phylogenetic homogenization in these IEM gradient categories. Thus, despite the high mobility of bats, fragmentation still induces considerable levels of erosion of phylogenetic diversity, suggesting that the full amount of evolutionary history might not be able to persist in present-day human-modified landscapes. Communicated by Raphael K. Didham. Our study highlights the erosion of phylogenetic diversity of bat assemblages associated with habitat fragmentation and degradation in the world's largest and longest-running whole-ecosystem fragmentation experiment. This work advances our understanding of the effects of habitat modification on bats as key ecosystem service providers in tropical ecosystems.

Effects of Forest Fragmentation on the Vertical Stratification of Neotropical Bats

“…Yet, due to multiple and often interacting stressors, the region is facing rapid environmental change and since 1970 has lost over 790,000 km 2 (nearly 20%) of its original forest cover [8]. Although habitat loss and fragmentation continue to act as primary threats to the megadiverse Amazonian vertebrate communities [9][10][11], little is known about how their composition and structure across forest strata is affected by habitat modification.With roughly 1400 species globally [12], bats are the second largest mammalian order and account for 25% of the total mammal diversity in the Brazilian Amazon [13,14]. Powered flight allows bats to explore resources across the multilayered space of tropical rainforests and an increasing number of studies have documented changes in species abundance from ground to subcanopy and canopy levels in both the Neo-and Paleotropics (e.g., [15][16][17][18]).…”

“…Yet, due to multiple and often interacting stressors, the region is facing rapid environmental change and since 1970 has lost over 790,000 km 2 (nearly 20%) of its original forest cover [8]. Although habitat loss and fragmentation continue to act as primary threats to the megadiverse Amazonian vertebrate communities [9][10][11], little is known about how their composition and structure across forest strata is affected by habitat modification.…”

Consequences of Replacing Native Savannahs With Acacia Plantations for the Taxonomic, Functional, and Phylogenetic α- and β-Diversity of Bats in the Northern Brazilian Amazon

“…Habitat loss and fragmentation have been shown to have negative effects on tropical vertebrates (Willig et al, 2007;Coelho et al, 2014;Meyer et al, 2016;Saccol et al, 2017;Ramos Pereira et al, 2018;Aninta et al, 2019;Palmeirim et al, 2020). For bats, habitat conversion leads to decreased availability of roosts and food resources, which will affect their presence, abundance, and behaviour (Jones et al, 2009;Meyer et al, 2016).…”

“…For bats, habitat conversion leads to decreased availability of roosts and food resources, which will affect their presence, abundance, and behaviour (Jones et al, 2009;Meyer et al, 2016). The effects of habitat conversion also lead to a decrease in the genetic diversity of populations (Collevatti et al, 2020), and loss of richness, taxonomic, functional, and phylogenetic diversity (Ramos Pereira et al, 2018;Aninta et al, 2019). However, few studies have evaluated the effect of the conversion of natural vegetation to tree plantations, such as eucalyptus, on bat assemblages (see Meyer et al, 2016;Farneda et al, 2020;Mendes and Srbek-Araujo, 2020 for a review).…”

“…In general, studies carried out in the Neotropics, including Brazil, show that gleaning animalivorous bats are negatively affected by landscape changes such as habitat fragmentation, whereas frugivorous and nectarivorous bats may respond positively to such changes (Delaval and Charles-Dominique, 2006;Willig et al, 2007;Meyer and Kalko, 2008;Farneda et al, 2015Farneda et al, , 2020Meyer et al, 2016;Oliveira et al, 2017). These differential effects on different groups of bats have manifested as changes in species composition in human-modified landscapes, with losses of species, functions and lineages (Aninta et al, 2019;Farneda et al, 2020).…”