Landscape connectivity influences gene flow in a roe deer population inhabiting a fragmented landscape: an individual–based approach

TLDR

Agricultural changes and forest fragmentation can dramatically reduce landscape connectivity and animal dispersal, thereby limiting gene flow. The study examined how woodland connectivity affects gene flow in European roe deer in a fragmented landscape. Using 648 genotyped roe deer, the authors calculated genetic distances from 12 microsatellite loci and compared them to Euclidean and least‑cost distances derived from woodland corridors, testing correlations with Mantel tests. Least‑cost distances, reflecting wooded corridor use, correlated more strongly with genetic distances—particularly in females—indicating that woodland connectivity drives gene flow in this fragmented population.

Abstract

Abstract Changes in agricultural practices and forest fragmentation can have a dramatic effect on landscape connectivity and the dispersal of animals, potentially reducing gene flow within populations. In this study, we assessed the influence of woodland connectivity on gene flow in a traditionally forest‐dwelling species — the European roe deer — in a fragmented landscape. From a sample of 648 roe deer spatially referenced within a study area of 55 × 40 km, interindividual genetic distances were calculated from genotypes at 12 polymorphic microsatellite loci. We calculated two geographical distances between each pair of individuals: the Euclidean distance (straight line) and the ‘least cost distance’ (the trajectory that maximizes the use of wooded corridors). We tested the correlation between genetic pairwise distances and the two types of geographical pairwise distance using Mantel tests. The correlation was better using the least cost distance, which takes into account the distribution of wooded patches, especially for females (the correlation was stronger but not significant for males). These results suggest that in a fragmented woodland area roe deer dispersal is strongly linked to wooded structures and hence that gene flow within the roe deer population is influenced by the connectivity of the landscape.