A metapopulation approach to the analysis of long-term changes in the epiphyte vegetation on the host tree Annona glabra

Abstract

Abstract Question: Do vascular epiphyte species have a metapopulation structure? What are the qualitative and quantitative long-term changes of the complete vascular epiphyte vegetation in a particular host tree species? Location: Lowland forest on Barro Colorado Island (9°10′ N, 79°51′ W), Republic of Panama. Methods: In 1994 and 2002 we conducted a census of all vascular epiphytes growing on more than 1000 Annona glabra trees (= patches). Epiphyte species abundances were recorded at the tree level in each census. Results: The number of epiphyte individuals increased from ca. 15 000 to ca. 23 700 individuals during the census interval while the species composition on Annona glabra as a whole was rather stable. There was a strong positive relationship between occurrence in patches and local abundance of the species, and between species richness and host tree stand size. The dynamics of local populations of a given species were uncorrelated to each other; small and large local populations of most species h...