Data from: Epiphyll specialization for leaf and forest successional stages in a tropical lowland rainforest

Questions The importance of tropical rainforest gap dynamics
in biodiversity maintenance is not fully understood, in
particular for taxa other than trees and lianas. We used epiphylls on
rainforest leaves to study the importance of leaf- and forest-scale
succession in determining biodiversity patterns by characterizing
community change with leaf age in gaps and closed-forest
habitats. We asked: 1. Do epiphylls show
specialization for leaf and forest successional stages? 2. Can
early and late-successional epiphyllous species be
recognized at these two scales? 3. How do epiphyll
presence, species richness, and cover change with leaf
and forest successional stages?   Location Barro Colorado Island,
Panama.   Methods Data were collected from 420 leaves, in three
age groups and at two heights on shrubs in gaps and closed
forest. We calculated turnover and nestedness components of
dissimilarity to evaluate the importance of species replacement or
accumulation during leaf and forest succession. Using
generalized linear mixed models we determined what factors explain
epiphyll species occurrence, richness and cover.   
Results Closed forest contained more liverwort and lichen specialist
species than gaps. Specialist species were identified
for older leaves only. Dissimilarity between leaves
within age groups was dominated by turnover within and
between forest successional stages. Dissimilarity between leaf
age , at the site level, was dominated by nestedness, i.e.
species accumulation. Both in forest and
gaps, epiphyll presence and cover increased with leaf age for all taxa except fungi, while species richness increased only for lichens.   Conclusion Early and late forest successional stages both contribute to epiphyll species richness by harboring specialized species. Among leaf successional stages, young leaves contain a mere subset of the species found on older leaves. Epiphyll communities do not follow classic succession, in the sense of changes being driven by species replacement, but are characterized by species accumulation through time.