Lessons Learned in the Field About Habitat Fragmentation

Habitat fragmentation is a major concern in conservation. Several lessons about habitat fragmentation are given that were learned from field studies and conservation management programs on diverse species. These lessons are 1) the matrix (the environment in which the fragmented habitats are imbedded) maters as the demographic and genetic impact of fragmentation is strongly influenced by the matrix; 2) the habitat patches mater because different patches vary in important properties and cannot be regarded as identical units; 3) life history plasticity frequently emerges in management programs, which in turn enhances the importance of monitoring as initial predictions from previous life history data may no longer be valid; 4) geography alone can be misleading about fragmentation; 5) effective sizes are complex and incomplete descriptors of fragmented populations but useful when used properly; 6) fragmentation can preserve genetic diversity, and this beneficial property can be utilized to improve evolvability in reintroduction programs; and 7) even when habitat fragments are only a small portion of the landscape, they can play an important role in landscape resilience after human caused environmental changes. From these seven lessons another lesson emerges: habitat fragmentation can be managed by restoring the habitats, by altering the matrix, by using knowledge of particular species to design appropriate dispersal corridors, by doing translocations, and by taking advantage of the genetic diversity maintained by fragmented populations to enhance evolvability, among other management possibilities.