Landscape Context and Environmental Stochasticity Shape Genetic Management Outcomes in an Amphibian.

Landscape context can influence demographic rates and, consequently, the population genetic processes determining levels of genetic diversity. However, the role of landscape context is not always sufficiently considered in conservation management. For species with complex life cycles, such as amphibians, landscape context is particularly relevant because they rely on both aquatic and terrestrial habitats, the quality of which can vary across landscapes. Understanding how landscape context may influence these genetic processes is therefore important for effective management. We used population viability analysis (PVA) to simulate how landscape context may influence genetic and demographic outcomes for the great crested newt (Triturus cristatus) using two landscape-specific models representing boreal forest and agricultural landscapes. We assessed the sensitivity of model outcomes to parameter perturbations and evaluated management scenarios and potential threats at the metapopulation level. A key result was that environmental stochasticity strongly influenced genetic dynamics in both landscapes. The low-stochasticity forest model retained genetic diversity, responded strongly to management actions, and relied less on gene flow. In contrast, the high-stochasticity agricultural model experienced stronger genetic drift, responded weakly to management actions, and relied more on continuous gene flow. Our findings suggest that enhancing gene flow alone may be insufficient for maintaining genetic diversity, and that improving resilience to environmental stochasticity should be considered an important part of genetic management.