Temporal changes in population genetic dynamics of the eastern collared lizard, Crotaphytus collaris collaris, in response to forest fire management

The priority for many studies in conservation genetics is to understand the implications of disrupting the balance between random genetic drift and gene flow among populations. Approaching this issue is difficult in studies limited to one or a few years of data. This study explores the genetic response of a reintroduced population of eastern collared lizards, Crotaphytus collaris collaris, subjected to ten years of population isolation due to forest fire suppression followed by ten years of restoration of gene flow due to the initiation of prescribed burning.;Using six nuclear microsatellite loci, I first tested the hypothesis that changes in fire management regime affect levels of genetic diversity and population differentiation. I found that prior to prescribed burns, genetic diversity within glades decreased and populations became more differentiated. Following controlled burns, genetic diversity within glades increases and levels of population differentiation stabilize.;Indirect estimates of gene flow and direct measures of dispersal have been used interchangeably to make inferences about the degree of connectivity among populations. Natural populations, especially those of conservation concern, often violate the assumptions of indirect estimates. Here, I compare the performance of direct measures of dispersal, indirect estimates of gene flow, and direct measures of allele movement while the population fluctuates through different demographic stages. The results clearly identify periods where the methods are more concordant and where they are highly incongruent.;Finally, I compare genetic and geographic distances under different landscape constraints to test hypotheses about metapopulation dynamics in this system. Using multiple methods, I identify a general pattern of isolation by distance despite high levels of gene flow once prescribed burning encompasses the complete landscape. Likewise, the importance of a particular landscape feature, knolls, is revealed.;These studies elucidate the importance of incorporating a landscape-level approach to restoring population genetic processes in the eastern collared lizard.