Data from: Differences in epiphyte biomass and community composition along landscape and within-crown spatial scales

Vascular epiphytes contribute to the structural, compositional, and
functional complexity of tropical montane cloud forests because of their
high biomass, diversity, and ability to intercept and retain water and
nutrients from atmospheric sources. However, human-caused climate change
and forest-to-pasture conversion are rapidly altering tropical montane
cloud forests. Epiphyte communities may be particularly vulnerable to
these changes because of their dependence on direct atmospheric inputs and
host trees for survival. In Monteverde, Costa Rica, we measured vascular
epiphyte biomass, community composition, and richness at two spatial
scales: (1) along an elevation gradient spanning premontane forests to
montane cloud forests; and (2) within trees along branches from inner to
outer crown positions. We also compared epiphyte biomass and distribution
at these scales between two different land-cover types, comparing trees in
closed canopy forest to isolated trees in pastures. An ordination of
epiphyte communities at the level of trees grouped forested sites above
versus below the cloud base, and separated forest versus pasture trees.
Species richness increased with increasing elevation and decreased from
inner to outer branch positions. Although richness did not differ between
land-cover types, there were significant differences in community
composition. The variability in epiphyte community organization between
the two spatial scales and between land-cover types underscores the
potential complexity of epiphyte responses to climate and land-cover
changes.