Rodent community landscape ecology in grassland-shrubland ecotones and gradients in the Chihuahuan Desert

Title	Rodent community landscape ecology in grassland-shrubland ecotones and gradients in the Chihuahuan Desert
Publication Type	Conference Paper
Year of Publication	2007
Authors	Campanella A., Bestelmeyer BT, Roemer G., Peters DC
Conference Name	22nd Annual Symposium of U.S. Regional Chapter of International Association of Landscape Ecology
Date Published	April 9-11, 2007
Conference Location	Tucson, AZ
ARIS Log Number	221828
Keywords	Chihuahuan Desert, diversity, rodent
Abstract	It is believed that the abundance and diversity of Chihuahuan Desert rodents increases with shrub encroachment accompanying desertification although grassland specialist species decline with loss of perennial grasses. It has been reported, however, that rodent population responses to spatial variation in habitat are mediated by a complex suite of biotic-abiotic interactions. The consistency of such patterns across a landscape has not been examined. We tested the hypothesis that rodent richness, biomass, and density/abundance were highest in shrub-dominated portions of replicate grassland-shrubland ecotones and across a grassland-shrubland gradient. Rodents were trapped on permanent grids scattered over an area of 200 km2. Mark-recapture procedures were used to estimate population density and the software eCognition to estimate landscape structure using an object-oriented spatial analysis approach. We found that rodent abundance, biomass, and species composition were highly variable and related to the details of vegetation structure across the landscape, rather than being simply positively correlated with shrub cover.