Meeting Abstract
Epiphytic plants may exhibit complex spatial patterns within forest communities that reflect multiple factors, including: microclimatic variables, environmental stability, and modes of reproduction. However, developing predictive models of epiphyte distributions requires basic information about the spatial distribution of individuals at multiple sampling extents. In a previous study, based on sampling Spanish moss coverage on all phorophytes within 50 x 50 m quadrats, we found evidence of spatial gradients in Spanish moss coverage in both forest communities sampled [i.e., 1) pine-dominated forest, and 2) a mixed hardwood and pine secondary forest]. However, it was not clear whether the gradients detected represented global trends at the stand level or the edges of localized patches within a stand. To clarify patterns at the stand level, in the present study, we sampled linear transects through each forest community and calculated the average rank coverage of Spanish moss on all phorophytes at 10 m intervals. To assess spatial pattern, we plotted average Spanish moss coverage at each point and used spatial correlogram analysis to assess pattern. While patterns varied among transects and between forest communities, results showed clear evidence of stand level gradients in Spanish moss coverage, usually emanating from the edges of the forest stand. Results also revealed localized patchiness superimposed on stand level gradients, indicating different spatial patterns at different spatial scales. Our results suggest that studies seeking to delineate predictors of Spanish moss abundance should use statistical models that can resolve multiple scales of spatial structure, and that edge effects between forest communities might be predictive of stand level spatial gradients.
