Amphibian communities in two contrasting ecosystems: functional diversity and environmental filters

Functional diversity is a tool for understanding biological communities and the influence of environmental filters on assembly rules. However, few studies explore the relationships of diversity metrics across contrasting ecosystems. We evaluated the effect of ecosystems (tropical dry forest and pine-oak forest) and seasons (wet and dry) on the functional diversity and community composition of amphibians in western Mexico. Our study showed that associations among metrics of diversity were not constant across contrasting ecosystems. The amphibian communities were related to changes in the environmental variables of elevation, temperature and relative humidity. We analyzed the functional diversity of the amphibian community based on 11 traits related to reproduction, trophic flow and habitat use. Seven functional groups with distinct ecological characteristics were detected, of which, four presented functional redundancy and two were represented by a single species. While the tropical dry forest during the wet season showed the highest species richness, the richness and diversity of functional groups were significantly lower than in the pine-oak forest in both seasons. These results suggest that the seasonal drought in the tropical dry forest could act as an environmental filter, promoting dominance of similar functional traits among species, while limiting similarity could be acting in the pine-oak forest, in the face of relatively stable hydric conditions, allowing a greater functional diversity. Analysis of the relationship between biological communities and ecosystem functioning is necessary to undertake conservation strategies.