Demography versus habitat fragmentation as determinants of genetic variation in wild populations Original Research Article

A critical question in conservation biology concerns how loss of natural habitat affects the persistence of plant and animal populations and the distribution of genetic variation within them. In this study a simulation model was used to examine how primary demographic and habitat factors affect secondary population processes and thereby influence population genetic structure. The model revealed that both genetic diversity and divergence were most affected by the proportion of patches in a landscape that remain occupied, which in turn was affected primarily by patch disturbance frequency. Patch carrying capacity also controlled the density of individuals within patches and thereby influenced levels of diversity within populations. Habitat availability influenced dispersal success and thereby secondarily influenced genetic divergence among populations. This study emphasizes that conservation of genetic diversity in wild populations should be based on both habitat and population management and can best be achieved by maintaining healthy sized, local populations well-distributed among a network of infrequently disturbed habitats.