Distribution of Woodland Species in Farmland Woods

Abstract

This study compared the distribution of plants and animals in discontinuous forest in farmland to the distribution of the same species in continuous forest. Indices were used to test whether the isolation of woods in farmland has caused the distribution of woodland organisms to be changed in the way predicted by the equilibrium theory of island biogeography. There was no consistent response of taxa to the fragmentation of forest. The pattern of distribution of fewer than 10% of taxa is consistent with the predictions of island theory, and additional data available for some of these taxa diminish the probability that insular processes have contributed to their present pattern. Farmland south of Ottawa [Canada] does not operate as a system of biogeographic islands, because woodland species have long since evolved efficient mechanisms for medium-distance movement in response to the ubiquitous spatial heterogeneity of intact, continuous forest.