A Conceptual Model for Integrative Studies of Epiphytes: Nitrogen Utilisation, a Case Study

Abstract

A conceptual, hierarchical model for the study of epiphytes in complex rainforest ecosystems is illustrated. The model incorporates an integrative, multidisciplinary approach with ecological parameters compartmentalised into relevant spatial, temporal and organisational scales. The model can be applied to other spatially complex ecosystems such as coral reefs. An example showing the use of the model is presented. The natural abundance of 15N in three species of epiphyte growing on one tree is examined. In this pilot study, interpretation of a complex data set has been aided by the use of a hierarchical approach. A high degree of spatial heterogeneity in the nitrogen pool within the tree was found, with epiphytes accessing at least three sources of nitrogen: an atmospheric source, a nitrogen fixed source and the phorophyte itself through decomposed litter.