Data from: Species sorting and mass effect along forest succession: evidence from taxonomic, functional, and phylogenetic diversity of amphibian communities

Species recovery after forest disturbance is a highly studied topic in the
tropics, but considerable debate remains on the role of secondary forests
as biodiversity repositories, especially regarding the functional and
phylogenetic dimensions of biodiversity. Also, studies generally overlook
how alpha and beta diversities interact to produce gamma diversity along
successional gradients. We used a metacommunity approach to assess how
species sorting (i.e., environmental filtering) and mass effect (i.e.,
source‐sink dynamics) affect 14 complementary metrics of amphibian
taxonomic, functional, and phylogenetic diversity along a successional
gradient in southern Mexico. As amphibians have narrow environmental
tolerances and low dispersal capabilities, we expected that species
sorting may be relatively more important than mass effect in structuring
amphibian communities. Between 2010 and 2012, we sampled frogs,
salamanders, and caecilians in 23 communities distributed in four
successional stages: young (2–5 years old) and intermediate (13–28 years
old) secondary forests, old‐growth forest fragments, and old‐growth
continuous forest. We assessed 15 ecologically relevant functional traits
per species and used a time‐calibrated molecular phylogeny. We recorded
1,672 individuals belonging to 30 species and 11 families. Supporting our
expectations from the species sorting perspective, from the poorest
(younger forests) to the best quality (continuous forest) scenarios, we
observed (a) an increase in alpha diversity regardless of species
abundances; (b) a clear taxonomic segregation across successional stages;
(c) an increase in functional richness and dispersion; (d) an increase in
mean phylogenetic distance and nearest taxon index; and (e) a reduction in
mean nearest taxon distance. However, 10 species occurred in all
successional stages, resulting in relatively low beta diversity. This
supports a mass effect, where interpatch migrations contribute to prevent
local extinctions and increase compositional similarity at the regional
scale. Our findings indicate that amphibian metacommunities along forest
successional gradients are mainly structured by species sorting, but mass
effects may also play a role if high levels of forest cover are conserved
in the region. In fact, secondary forests and forest fragments can
potentially safeguard different aspects of amphibian diversity, but their
long‐term conservation value requires preventing additional deforestation.