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A hierarchical framework for investigating epiphyte assemblages: networks, meta‐communities, and scale
Author(s) -
Burns K. C.,
Zotz G.
Publication year - 2010
Publication title -
ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.144
H-Index - 294
eISSN - 1939-9170
pISSN - 0012-9658
DOI - 10.1890/08-2004.1
Subject(s) - epiphyte , ecology , biological dispersal , biology , context (archaeology) , species richness , seed dispersal , community , ecosystem , population , paleontology , demography , sociology
Epiphytes are an important component of many forested ecosystems, yet our understanding of epiphyte communities lags far behind that of terrestrial‐based plant communities. This discrepancy is exacerbated by the lack of a theoretical context to assess patterns in epiphyte community structure. We attempt to fill this gap by developing an analytical framework to investigate epiphyte assemblages, which we then apply to a data set on epiphyte distributions in a Panamanian rain forest. On a coarse scale, interactions between epiphyte species and host tree species can be viewed as bipartite networks, similar to pollination and seed dispersal networks. On a finer scale, epiphyte communities on individual host trees can be viewed as meta‐communities, or suites of local epiphyte communities connected by dispersal. Similar analytical tools are typically employed to investigate species interaction networks and meta‐communities, thus providing a unified analytical framework to investigate coarse‐scale (network) and fine‐scale (meta‐community) patterns in epiphyte distributions. Coarse‐scale analysis of the Panamanian data set showed that most epiphyte species interacted with fewer host species than expected by chance. Fine‐scale analyses showed that epiphyte species richness on individual trees was lower than null model expectations. Therefore, epiphyte distributions were clumped at both scales, perhaps as a result of dispersal limitations. Scale‐dependent patterns in epiphyte species composition were observed. Epiphyte–host networks showed evidence of negative co‐occurrence patterns, which could arise from adaptations among epiphyte species to avoid competition for host species, while most epiphyte meta‐communities were distributed at random. Application of our “meta‐network” analytical framework in other locales may help to identify general patterns in the structure of epiphyte assemblages and their variation in space and time.