Oaks are one of the most important biological groups in the Neotropical forest. In Mexico, oaks are key elements of highly threatened and biodiverse ecosystems such as the Montane Cloud Forest (MCF). A representative species of the treats currently faced by both, oak species and the cloud forest, is Quercus insignis. Such species characterizes by a highly fragmented distribution from Mexico down to Panama, small and low-density populations associated to several land use change drivers such as agriculture and cattle rising.
Our main objective is to set the bases for the study and conservation of MCF, bringing together several approaches such as population ecology, landscape ecology and genetics, using Quercus insignis as a model species. Particularly, we aimed to describe the species population structure, characterize its genetic diversity and structure, to test for possible changes in the genetic diversity along age-stages and, and to identify the effectiveness of in situ conservation strategies.
Floristic survey was developed in order to characterize floristic composition and structure of the MCF, using transects following Gentry’s methodology. Plants were taxonomically identified and measured for DBH and height. Demographic monitoring was carried out using plots, where all Q. insignis individuals were measured and tagged. Height and DBH were documented yearly for each individual, and distances among nearest individuals were recorded. Genetic characterization was performed using high quality DNA. We used nuclear and chloroplast microsatellites in order to genotype the species variation. Genetic structure and diversity were evaluated. Also, genetic erosion was tested by comparing the values of genetic diversity between seedlings, juvenile and adult stages. Finally, ecological niche modelling was used in order to test for changes in the species habitat suitability under climate change scenarios, an to estimate the degree of connectivity between populations.
Demographic studies suggest that species has a low-density structure. Also, genetic diversity is comparable to other oak species with high genetic variation. However, genetic structure results shown strong differentiation between the species populations. We did not find evidence of genetic erosion between the development stages for the species. Finally, we detected a well-defined reduction of climatic suitable areas for the species under climate change scenarios, as well as contrasting connectivity scenarios. Despite the growing treats for the species, genetic diversity and demographic data suggest that the species still maintain conditions to favor its conservation. However, there is a growing need to improve the conditions to favor the species connectivity, and therefore, its persistence in the future.
Quercus, Montane Cloud Forest, Conservation, Ecology, Genetics