Differential effects of landscape-level environmental features on genetic structure in three co-distributed tree species in Central America

Landscape genetic studies use spatially explicit population genetic information to determine the physical and environmental causes of population genetic structure on regional scales. Comparative studies that identify common barriers to gene flow across multiple species within a community are important to both understand the evolutionary trajectories of populations and to prioritize habitat conservation. Here, we use a comparative landscape genetic approach to ask whether gradients in temperature or precipitation seasonality structure genetic variation across three co-distributed tree species in Central America, or if a simpler (geographic distance) or more complex, species-specific environmental niche model is necessary to individually explain population genetic structure. Using descriptive statistics and causal modeling, we find that different environmental factors best explain genetic distance in each of the three species: environmental niche distance in Bursera simaruba, geographic d...