Patch dynamics in a landscape modified by ecosystem engineers

ConclusionsThe set of models developed here helps link thepopulation dynamics of ecosystem engineers to thedynamics of the patches that they create. By predictingthe relative abundance of engineered and unengineeredpatches in a landscape, it has the potential to serve as animportant tool in determining the effects of ecosystemengineers on ecosystem structure and function at thelandscape scale. Application of the model to a populationof beaver in the central Adirondack Mountainssuggests that because successful colonization rates arelow and site abandonment rates are high, the populationpersistence may depend on dispersers from beavercolonies in unmodified patches such as natural lakes.Although we are not aware of any data set that wouldallow for complete parameterization of the model,analysis of the model suggests a number of possibletests of its structure and assumptions. The model makesnumerous testable predictions about how the distributionof patch types in a landscape should change inresponse to changes in the population dynamics ofengineers or the recovery rate of patches after theyhave been abandoned. Furthermore, by combining thismodel with an understanding of how ecosystem engineeringaffects diversity at the landscape scale, we nowhave the tools to relate the population dynamics of anorganism to patterns of landscape-level diversity.Acknowledgements / The authors gratefully acknowledge theAdirondack Ecological Center for access to the long-term dataset on beaver dynamics of the Huntington Wildlife Forest.Special thanks to C. Demers and R. Sage for their help inorganizing and maintaining this valuable resource. A. Flecker, P.Marks, B. Goodwin, R. Root and P. 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