Considering landscape connectivity and gene flow in the Anthropocene using complementary landscape genetics and habitat modelling approaches

Context A comprehensive understanding of how rapidly changing environments affect species gene flow is critical for mitigating future biodiversity losses. While recent methodological developments in landscape ecology and genetics have greatly advanced our understanding of biodiversity conservation, they are rarely combined and applied in studies. Objectives We merged multifaceted landscape habitat modelling with genetics to detect and design biological corridors, and we evaluated the importance of habitat patches to test corridor efficacy for gene flow in a fragmented landscape. We examined an isolated population of an endangered umbrella species, the capercaillie (Tetrao urogallus), in the Western Carpathians; they have experienced habitat deterioration and accompanying population declines in recent decades. Methods To detect spatial patterns of genetic distances, we combined and optimized resistance surfaces using species distribution modelling, structural and functional connectivity analyses, multivariate regression approaches, and Moran's eigenvector maps at hierarchical scales. Results Larger habitat patches had better gene flow among them, and we confirmed a broken metapopulation network characterised by a pattern of isolation by the environment. Distance to human settlements explained landscape genetic patterns better than other environmental and landscape features, MAXENT resistance, CONEFOR resistance surfaces, and the pairwise Euclidean distances among individuals. The closer individuals were to settlements, the more pronounced were the effects of logging and other negative factors on their connectivity. Conclusions Merging multifaceted landscape habitat modelling with genetics can effectively test corridor efficacy for gene flow, and it represents a powerful tool for conservation of endangered species.