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. Datos de abundancia, porcentaje de cobertura, y riqueza de especies fueron colectados para pastos de areas xeroriparias (areas riparias del desierto) a lo largo del Barry M. Goldwater Range, estado de Arizona, para entender como los pastos nativos de areas xeroriparias aisladas se relacionan al uso por la fauna silvestre, plantas exoticas invasoras, y la comunidad floral contigua. Estos datos se analizaron para ver si existian asociaciones significativas con dos caracteristicas del paisaje: la matriz contigua de comunidad de plantas y la distancia al agua proporcionada a la fauna silvestre (como sustituto de uso a largo plazo por la fauna silvestre). La matriz contigua de comunidad de plantas, ya sea matorral desertico creosota-bursage o de palo verde-cactus mixtos-matorrales mixtos en las bajadas, tuvo una influencia significativa en las comunidades de pastos nativos y exoticos en los habitas xeroriparios, lo cual sugiere que se pueden predecir las caracteristicas de comunidades de pastos observadas en el desierto Sonorense si se conocen las distribuciones de plantas a gran escala. El aumento de la cobertura de plantas exoticas se asocio con la disminucion de riqueza nativa. La distancia al agua para la fauna silvestre no tuvo ninguna relacion significativa, lo cual sugiere