Climate Change Impacts on the Genetics of Post-Fire Regeneration and Reproductive Phenology

Abstract

Evidence regarding fast climatic change is constantly accumulating and has been linked to an ongoing increase of fire occurrence and reproductive phenology modifications, both being crucial factors in the evolution of forest tree populations. Studying the effects of forest fires in the gene pool, it was found that in basic genetic diversity parameters that reflect the magnitude of genetic variation in natural populations, no significant differences between post-fire and control populations were observed. Nevertheless, the genetic architecture of post-fire populations compared to control populations presented some differences in the frequencies of rare alleles, the occurrence of interspecific hybridization in the post-fire populations and the observation of genetic bottleneck effects, especially in isolated populations. Forest fires may not induce genetic erosion in forest tree populations per se however population isolation compounded by periods of high forest fire frequency and intensity, may lead to adverse consequences for the architecture of the genetic diversity of forest trees. Such consequences may be compounded by reduced natural regeneration due to the decreased percentage of sound seed, a result of the anticipated reduction of tree fertility and flowering synchronization, induced by climatic change.