Metacommunity Dynamics Over 16 Years in a Pyrogenic ShrublandDinamica de la Metacomunidad Durante 16 Anos en un Matorral Pirogenico

• Published in: Conservation biology 2012-04, Vol.26 (2), p.357-366
• Main Authors: Miller, Timothy J, Quintana-Ascencio, Pedro F, MALIAKAL-WITT, SATYA, Menges, Eric S
• Format: Article
• Language: English
• Subjects: Rosmarinus
• ISSN: 0888-8892; 1523-1739
• DOI: 10.1111/j.1523-1739.2011.01807.x

Metacommunity theory allows predictions about the dynamics of potentially interacting species' assemblages that are linked by dispersal, but strong empirical tests of the theory are rare. We analyzed the metacommunity dynamics of Florida rosemary scrub, a patchily distributed pyrogenic community, to test predictions about turnover rates, community nestedness, and responses to patch size, arrangement, and quality. We collected occurrence data for 45 plant species from 88 rosemary scrub patches in 1989 and 2005 and used growth form, mechanism of regeneration after fire, and degree of habitat specialization to categorize species by life history. We tested whether patch size, fire history, and structural connectivity (a measure of proximity and size of surrounding patches) could be used to predict apparent extinctions and colonizations. In addition, we tested the accuracy of incidence-function models built with the patch survey data from 1989. After fire local extinction rates were higher for herbs than woody plants, higher for species that regenerated only from seed than species able to resprout, and higher for generalist than specialist species. Fewer rosemary specialists and a higher proportion of habitat generalists were extirpated on recently burned patches than on patches not burned between 1989 and 2005. Nestedness was highest for specialists among all life-history groups. Estimated model parameters from 1989 predicted the observed (1989-2005) extinction rates and the number of patches with persistent populations of individual species. These results indicate that species with different life-history strategies within the same metacommunity can have substantially different responses to patch configuration and quality. Real metacommunities may not conform to certain assumptions of simple models, but incidence-function models that consider only patch size, configuration, and quality can have significant predictive accuracy.Original Abstract: Resumen:La teoria de metacomunidades permite predicciones de la dinamica de ensambles de especies potencialmente interactuantes que estan conectadas mediante la dispersion, pero son raras pruebas empiricas robustas de la teoria. Analizamos la dinamica de la metacomunidad de matorral de romero de Florida, una comunidad pirogenica distribuida heterogeneamente, para probar predicciones sobre tasas de recambio, anidamiento de la comunidad y respuestas al tamano, arreglo y calidad del parche. Recolectamos datos de ocurrencia