|Hochstrasser, Tamara - NEW MEXICO STATE UNIV|
|Fehmi, Jeffrey - USA ERDC-CERL|
Submitted to: Ecological Society of America Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: July 1, 2002
Publication Date: August 1, 2002
Citation: HOCHSTRASSER, T., PETERS, D.C., FEHMI, J.S. DISTURBANCE, VEGETATION AND CLIMATE: DETERMINING CRITICAL FACTORS AFFECTING RECOVERY IN DESERT GRASSLANDS. ECOLOGICAL SOCIETY OF AMERICA ANNUAL MEETING. 2002. ABSTRACT P. 159. Technical Abstract: In arid ecosystems, disturbances such as fire and grazing are attributed both to ecosystem degradation and to restoration. The objective of this study was to determine the disturbance and climatic conditions that maintain current vegetation and the conditions that result in a shift to different vegetation types. Because life history and physiological characteristics of plants can filter the impact of disturbances, vegetation change may also depend on the current vegetation type. We used an individual-based simulation model (ECOTONE) to investigate how differences in characteristics of grasses and shrubs determine their responses to disturbances under different climate scenarios in the desert grasslands of southern New Mexico. The simulated disturbance types included those that remove aboveground biomass from the entire plant community, those that only remove the biomass from certain species, and those that only affect soil characteristics. Climatic conditions during recovery from disturbance were simulated to include short-term and long-term droughts and wet periods. We found the timing of the disturbance with respect to climatic events played an important role in determining the lifeform that recovered more quickly. Drought impacted grass recovery more than shrub recovery. Dispersal and establishment characteristics were the most important traits for grass recovery, whereas the most important characteristic for shrubs was biomass allocation pattern. Our results revealed complex interactions among vegetation, disturbance, and climate and all three appear important for maintenance and restoration of grasslands in arid regions.