Ecological differences and limiting factors in different regional contexts: landscape genetics of the stone marten in the Iberian Peninsula

Landscape genetics focuses on quantifying relationships between landscape features and gene flow. Most past landscape genetic studies have addressed relationships between landscape structure and genetic differentiation in single study areas. However, failure to investigate multiple areas across a species range could produce misleading inferences about which landscape variables generally limit gene flow in a given species resulting in faulty management decisions. The main objectives of this paper were to identify the landscape features that facilitate or impede stone marten gene flow across its Iberian range, and to test whether gene flow is always influenced by the same set of landscape features or if they are detected only when they are limiting in a particular landscape. We conducted an individual-based meta-replicated landscape genetic analysis using multivariate-restricted optimization with reciprocal causal modeling in three study areas within the Iberian Peninsula with strongly contrasting landscape characteristics. Variables explaining the stone marten distribution differed among areas, confirming that relationships between genetic connectivity and landscape features are variable across Iberia. We found clear patterns in which variables were included in the final optimized model related to how limiting those variables were to gene flow in each particular study area. This study highlights that variability in limiting factors can have a large effect on predictions of which landscape features affect gene flow. Our results suggest that landscape models specific to the region of interest should be developed before proposing management and conservation actions, and contribute to the growing understanding of limiting factors in landscape genetics.