Genetic Consequences of Fire to Natural Populations

Abstract

Fire plays an important role in many ecosystems worldwide. The implications of fire on population and community dynamics in natural ecosystems have been studied extensively. Nevertheless, the impact of fire on genetic diversity, a crucial component of biodiversity, remains largely under-investigated. We summarize the theoretical expectations on how ecological effects of fire can be translated into genetic impact in natural populations. We formulate predictions on the effect of fire on genetic variance between and within populations, on the change in allelic frequencies and on the spatial genetic structure within populations. We review the empirical evidence for the effect of fire on genetic characteristics of natural populations. Thus far, research on the genetic consequences of fire has been limited to plant populations with a few exceptions of reptile populations. Because the genetic impact of fire is diverse and complex, consideration of simultaneous ecological effects of fire, controlled analyses of pre-/post-fire in the same study site, and comparison of species differing in their ecological response to fire is crucial for disentangling the mechanisms by which fire affects genetic characteristics of natural populations. The expected increase in fire frequency and extent in natural ecosystems as a result of global climate change stresses the importance of understanding the genetic impact of fire. As more and more genetic data on natural populations in fire-prone habitats accumulate, this challenge will be advanced.

Keywords:

• fire
• genetic impact
• genetic diversity
• gene flow
• spatial geneticc structure