摘要：WE ANALYZED THE PATTERNS OF DISTRIBUTION OF MAMMAL SPECIES RICHNESS IN JALISCO STATE AND THEIR RELATIONSHIPS WITH SOME ENVIRONMENTAL FACTORS. WE RETRIEVED DISTRIBUTION DATA FROM SEVERAL NATIONAL AND FOREIGN BIOLOGICAL COLLECTIONS. WE USED THE COLLECTING LOCALITIES TO GENERATE A SPATIAL RECORD OF DISTRIBUTION POINTS. THE STATE WAS DIVIDED INTO 159 GEOGRAPHIC UNITS OF CLASSIFICATION (GUC´S) OF 15” BY 15”. WE OVERLAP THE POINT COVER, GUCS AND SOME MAPS FROM CONABIO TO CREATE A PRESENCE-ABSENCE MATRIX. WE ANALYZED THE RICHNESS DISTRIBUTION BY VEGETATION TYPE AND ELEVATION. A RICHNESS GRADIENT WAS OBSERVED FROM TROPICAL TO SEMIARID VEGETATION TYPES AND ACCORDING TO ELEVATION; WE OBSERVED HIGHER RICHNESS BETWEEN 1500 AND 2000 M A. S. L. AND LOWER RICHNESS BETWEEN 4000 TO 4500. A BRAY-CURTIS ORDINATION AND A CLASSIFICATION TWINSPAN WERE USED. THEY WERE CONSISTENT IN SEPARATING TWO GROUPS OF SPECIES: ONE OF THEM INCLUDING COASTAL SPECIES AND THE OTHER WITH NORTHEASTERN SPECIES, REFL ECTING A CLIMATIC GRADIENT. THE PERCENTAGE OF ACCUMULATED VARIANCE WAS 94% AND PRECIPITATION, TEMPERATURE, EVAPORATION, ELEVATION AND VEGETATION WERE THE MOST IMPORTANT ENVIRONMENTAL VARIABLES.
