Submitted to: Ecological Society of America Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 7/1/2000
Publication Date: 8/6/2000
Citation: PETERS, D.C., GOSZ, J.R. CONTROLS ON PATTERNS IN SPECIES DOMINANCE ACROSS MULTIPLE SPATIAL SCALES AT A BIOME TRANSITION ZONE. 85TH ANNUAL MEETING, ECOLOGICAL SOCIETY OF AMERICA. 2000. ABSTRACT P. 372.
Technical Abstract: Grassland landscapes at the SEV-LTER consist of a mosaic of patches of variable size and shape that are dominated or codominated by one of two Bouteloua species that characterize two other LTER sites. Bouteloua gracilis (blue grama) dominates shortgrass steppe ecosystems at the SGS-LTER in northern Colorado, and B. eriopoda (black grama) dominates Chihuahuan Desert grasslands at the JER-LTER in southern New Mexico. Our overall objective of this ongoing work is to examine controls on patterns in dominance by these species at the shortgrass steppe/Chihuahuan Desert biome transition zone in central New Mexico. A combination of field investigations, experiments, and simulation model analyses are being used to evaluate the key abiotic variables and biotic processes controlling these patterns. Broad-scale patterns in dominance are related to interactions between climate, topography, and soils. As the spatial scale decreases, the importance of patchily distributed disturbances to species dominance increases. Recruitment strategies and temporal partitioning of soil water are key processes determining dominance patterns under different environmental conditions. Predictions from simulation model analyses indicate that a trend toward hotter growing seasons or an increased frequency of disturbance will result in shifts in dominance to black grama, the Chihuahuan Desert species.