Fragmentation effects on beech genetic structure

Abstract

An objective of an ecologically sustainable forest management is the conservation of genetic variability. Genetic variability is required for species to survive and reproduce in the array of conditions they face. The conservation of genetic variability is a pre-condition for the future evolution and adaptability of local populations and species. To understand the impact of forest management on genetic diversity is necessary to define the number of individuals that exchange genes, the area they cover and in turn which is the smallest level of habitat fragmentation that has an effect on genetic diversity. For this purpose we studied 25 beech population (Fagus sylvatica L.) from Central Italy selected to represent three increasing level of fragmentation: nearmarginal populations, remote-summit populations, remote-abyssal populations. Thirty plants per population were sampled and local coordinates were recorded for each plant. Individuals were characterized with 5 SSR markers. Analysis of variance on the number of alleles, on FIS, observed and expected heterozygosity shows that the three groups (Near-Marginal, Remote-Summit and Remote-Abyssal) do not differ. By F-statistic analysis performed on genetic data, we found a significant higher FSG value among near-abyssal populations. Principal coordinates analysis performed on the pair-wise genetic matrix confirms previous result: remote-abyssal populations do not appear in a unique clear cluster and are widespread in the plot. Remotesummit population and near-marginal populations are less spread out and are mostly found around the center of the plot.