Landscape variables as predictors of characteristics of native-grass communities in xeroriparian areas of the Sonoran Desert

Data on density, percentage of cover, and species richness were collected for grasses occurring in xeroriparian (desert riparian) areas across the Barry M. Goldwater Range, Arizona, to understand how native grasses occurring in isolated xeroriparian areas are related to use by wildlife, exotic invasive plants, and the surrounding floral community. These data were analyzed for significant associations with two aspects of landscape: adjoining matrix community of plants; distance from water-developments for wildlife (as a proxy for long-term use by wildlife). The adjoining matrix community, either Creosote-Bursage Desert Scrub or Palo Verde-Mixed Cacti-Mixed Scrub on Bajadas, had a significant influence on communities of native and exotic grasses in xeroriparian habitats, suggesting that observed characteristics of these communities can be predicted in the Sonoran Desert when large-scale distribution of floral communities are known. Increasing cover of exotic plants was associated with decreasing native richness. Distance to water-developments for wildlife had no significant relationship, suggesting that use associated with this water was not a significant driver of communities of grass.