Spatial heterogeneity in aboveground net primary production and species richness at multiple scales in the Chihuahuan Desert

TitleSpatial heterogeneity in aboveground net primary production and species richness at multiple scales in the Chihuahuan Desert
Publication TypeConference Paper
Year of Publication2011
AuthorsYao J, Peters DC
Conference NameUS-International Association for Landscape Ecology
Date Published04/2011
Conference LocationPortland, OR
ARIS Log Number262573
AbstractWe analyzed patterns in spatial heterogeneity and the processes driving these patterns in two ecosystem properties, aboveground net primary production (ANPP) and species richness, at multiple scales in the Chihuahuan Desert.  We used long-term data (1990-2009) to examine the importance of a suite of drivers and ecosystem properties to patterns in ANPP and species richness at two spatial scales: patch and landscape unit.  Three patches were sampled annually within each of five landscape units: upland and playa grasslands, and mesquite, creosotebush, and tarbush shrublands. Spatial heterogeneity at the patch scale was measured as the coefficient of variation across quadrats (n = 48 or 49).  Spatial heterogeneity at the landscape unit scale was measured as the coefficient of variation across patches.  At the patch scale, heterogeneity was affected by growth form of the dominant plant species and by precipitation. Grasslands were more homogeneous than shrublands under drought conditions, but shrublands were more homogeneous in wet years. At the landscape unit scale, heterogeneity was mainly affected by variation in distance between patches and variation in precipitation. Because of high spatial heterogeneity across these diverse landscapes, we concluded that estimates of ANPP and species richness from fine scales can not be directly extrapolated to broader scales in the Chihuahuan Desert without accounting for both local and spatial drivers of processes.