Nocturnal rodents at the edge of a microphyllous shrubland and gypsophilous grassland in San Luis Potosí, Mexico

Abstract

IN THIS STUDY WE COMPARED ABUNDANCE AND SPECIES RICHNESS OF NOCTURNAL RODENTS AT THE EDGE OF GYPSOPHILOUS GRASSLAND ON AN EXPOSED GYPSUM SUBSTRATE AND 3 SITES OF MICROPHILOUS SHRUBLAND, IN NORTHERN SAN LUIS POTOSÍ, MEXICO. WE SAMPLED AT SITES THAT DIFFERED IN EDAPHIC CHARACTERISTICS AND VEGETATION STRUCTURE, IN THE WET AND DRY SEASONS OF 2003 AND 2004. AS A POPULATION ESTIMATOR WE USED THE NUMBER OF INDIVIDUALS CAPTURED IN EACH SAMPLING PERIOD. WE CAPTURED 414 INDIVIDUALS OF 12 SPECIES OF HETEROMYIDAE AND MURIDAE. WE CONCLUDED THAT 1) RODENT COMMUNITIES WERE DIFFERENT AMONG SITES AS A FUNCTION OF VEGETATION STRUCTURE, AND VARIED NOTABLY BETWEEN GRASSLAND AND ADJACENT SHRUBLANDS: 2) SUCH COMMUNITIES REFL ECTED THE VEGETATION MOSAIC MORE THAN SEASON OF THE YEAR: 3) THE THREE SHRUBLAND TYPES MAINTAINED THEIR IDENTITY THROUGHOUT THE YEAR; Y 4) LOW PRECIPITATION AND/OR GRAZING, THROUGH THE REDUCTION OF PLANT COVER, ON GYPSOPHILOUS SOILS AFECTED THE RODENTS.