Rodent communities in two natural and one cultivated 'nopaleras' (Opuntia spp.) in north-eastern Jalisco, Mexico

摘要

In north-eastern Jalisco one of the most notorious original habitat features were xerophitic shrubs formed of different types of nopaleras (communities of flat-stemmed Opuntia cacti). Expansion of human activities have reduced these habitats but, conversely, perennial agroecosystems of domesticated varieties of native Opuntia spp. have been established. During 1997 I conducted a study to describe the rodent communities in two natural nopaleras, one arboreal and one arbustive, and one fruit-oriented cultivated nopalera. I recorded 14 rodent species at the three sites. There were no significant differences in total and seasonal abundances between sites, although some rodent species exhibited site-specific preferences and their abundances differed significantly between sites. Species richness ranged from 10 to 14. The arboreal nopalera had a significantly lower species richness than the arbustive and the cultivated nopaleras. The principal component analysis (PCA) clearly separated the arboreal nopalera from the other two based on the vegetative structure. Although agroecosystems have been considered as low diversity habitats, my results showed that fruit-oriented, cultivated nopaleras in north-eastern Jalisco create a habitat mosaic that is used by rodent species from different guilds. This suggests that these agroecosystems can contribute to the maintenance of local and regional rodent biodiversity in this severely fragmented region.