PoTENTIAL DISTRIBUTIoN oF RIPARIAN TREES IN THE BAjo RIo GRIjALvA SUB BASIN

Background: Potential distribution models are widely used to estimate and predict changes in the distribution of a species in response to dif-ferent processes of global change. Knowing the extent and distribution of vegetation is a basic step for measuring the environmental status of a basin. Questions: What are the bioclimatic variables that most contribute to the distribution of riparian trees in a basin? What is the environmental similarity among distributed species in a basin? Studied species: 17 species of riparian trees. Study site and dates: Bajo Rio Grijalva sub basin, January - December 2020. Methods: Potential distribution models were obtained for 17 riparian tree species using 19 climate variables and three topographic variables using the Maximum Entropy method. The evaluation of the models was done with the results of the analysis of the area under the curve (AUC). Results: The models presented an AUC value > 0.8 for most species. The results obtained showed maps of potential distribution of the 17 spe-cies, 11 of them distributed in the part of the study area with highest altitude, 13 in the middle part, and all match in the part with the lowest altitude. Upon analyzing the bioclimatic profile of the modeled species, it was observed that the slope, aspect and elevation were the variables that determined in greater proportion the potential distribution of species. Conclusions: When analyzing the similarity of the species with respect to environmental variables, Haematoxylum campechianum stands out as the species with the environmental difference.