Back to the future of a rare plant species of the Chihuahuan desert: tracing distribution patterns across time and genetic diversity as a basis for conservation actions
Habitat fragmentation and its effects on the persistence of populations and species are of major concern to conservation biology. Penstemon coriaceus is a rare and endemic species from the Mexican Central Plateau and adjacent foothills of the Sierra Madre Occidental and Sierra Madre Oriental, which belongs to the Chihuahuan Desert ecoregion. This is the first study that integrates population genetics and ecological niche modeling analysis as tools to understand the distribution and genetic diversity patterns of a Penstemon species. We used AFLP markers for 144 individuals across 11 populations, and calibrated Ecological niche modeling for three different time periods (current, future and past). Population genetics analysis showed low levels of genetic diversity at the population level and high genetic differentiation among populations. Ecological niche modeling analysis revealed an important decline of the distribution range due to climate change, which can be considered as an indicator for the vulnerability of temperate forest. The integration of both methods revealed that the genetic differentiation observed only show a relationship with the environment variables and the habitat suitability, but not with the geographical distribution of the populations sampled; which indicate the importance of the environmental factors in the determination of genetic processes for P. coriaceus .