Diversity of rodents in a prairie-to-mountain system in the Chihuahuan Desert

Diversity patterns of rodent communities along elevational gradients are recognized in the Chihuahuan Desert; however, local variation in community composition and species turnover remains poorly understood. Because anthropogenic pressures vary among ecosystems, identifying biotic transitions is critical for conservation planning. We estimated rodent diversity across five prairie-to-mountain ecosystems in the Janos Biosphere Reserve, Chihuahua, Mexico, along an elevational gradient from 1,300 to 2,600 m asl. The studied ecosystems included scrubland, two grasslands (with and without black-tailed prairie dogs, Cynomys ludovicianus), oak forest (Quercus spp.), and pine forest (Pinus spp.). We hypothesized that rodent communities would show strong habitat associations, with higher species turnover between prairie and mountain ecosystems than within each ecosystem type. Rodents were sampled during dry, wet, and winter seasons, and we estimated species richness, dominance, and species turnover for each ecosystem. Each community was distinct, except for grasslands with and without prairie dogs. Two major rodent assemblages were identified: prairie ecosystems (grasslands and scrubland) and mountain ecosystems (oak and pine forests). Scrubland was the most species-rich ecosystem (N = 15), encompassing all grassland species and acting as the only ecosystem sharing species with mountain forests. In contrast, oak and pine forests were less diverse (N = 6) and dominated by habitat specialists. Our results demonstrate that prairie and mountain ecosystems in the Janos Biosphere Reserve support two distinct rodent communities, highlighting the importance of ecosystem-specific conservation strategies.