COS 23-6 - Tropical forest restoration enriches vascular epiphyte recovery

Tuesday, August 9, 2016: 9:30 AM
Floridian Blrm A, Ft Lauderdale Convention Center
J. Leighton Reid, Center for Conservation and Sustainable Development, Missouri Botanical Garden, St. Louis, MO, José Miguel Chaves-Fallas, Las Cruces Biological Station, Organization for Tropical Studies, San Vito, Costa Rica; Department of Biology, University of Missouri-St. Louis, St. Louis, MO, Karen D. Holl, Environmental Studies Department, University of California, Santa Cruz, Santa Cruz, CA and Rakan A. Zahawi, Las Cruces Biological Station, Organization for Tropical Studies, San Vito de Coto Brus, Costa Rica

Epiphytes make up 10% of the world’s vascular plants, and they are among the slowest plants to recolonize secondary forests. But epiphytes are rarely considered in ecological restoration. We asked whether tree planting for ecological restoration accelerates epiphyte community recovery. Does the spatial configuration of tree planting matter? What landscape contexts are most suitable for epiphyte restoration? We addressed these questions in a series of restored pastures in premontane Costa Rica. We surveyed epiphytes growing on the lower trunks of 1083 trees in thirteen experimental restoration sites. Each site contained three 0.25-ha treatment plots: natural regeneration, trees planted in patches or “islands”, and tree plantations. Sites spanned elevational (1100-1430 m) and deforestation gradients (4-94% forest cover within a 100-m radius around each site).


Vascular epiphytes were twice as diverse in planted restoration plots (islands and plantations) as in natural regeneration; we observed this at the scale of individual host trees and within 0.25-ha treatment plots. Contributing factors included that trees in planted restoration plots were larger, older, more abundant, and composed of different species than trees in naturally regenerating plots. Epiphyte species richness increased with surrounding forest cover within 100-150 m of restoration plots. Epiphyte communities were also twice as diverse at higher (1330-1430 m) versus lower elevation sites (1100-1290 m). Epiphyte groups responded differently to restoration treatments and landscape factors; ferns were responsible for greater species richness in planted restoration plots, whereas angiosperms drove elevation and forest cover effects. Our results suggest that restoration practitioners can accelerate epiphyte recovery by planting trees in suitable landscapes. Where budgets allow, it may be worthwhile to transplant dispersal-limited species.