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ARS Home » Plains Area » Las Cruces, New Mexico » Range Management Research » Research » Publications at this Location » Publication #98852
Title: USING RESISTANCE AND RESILIENCE MEASUREMENTS FOR "FITNESS" TESTS IN ECOSYSTEM HEALTH

Author
item Whitford, Walter
item RAPPORT, DAVID - UNIV OF GUELPH, CANADA
item DE SOYZA, AMRITA - NEW MEXICO STATE UNIV

Submitted to: Journal of Environmental Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/5/1999
Publication Date: N/A
Citation: N/A

Interpretive Summary: Resistance refers to the ability to survive stress while resilience is the ability to recover from stress. We measured resistance and resilience of perennial grasses and the shrub snakeweed in areas that were affected to different degrees by livestock grazing. In areas that were intensely grazed only a few plants of the grasses and the shrub survived a drought, and few new plants became established after the drought ended. Plant survival and re-establishment was higher in the more lightly grazed sites. Thus areas that were heavily grazed were less "fit" in terms of resistance and resilience and were, therefore, less able to survive or recover from stress.

Technical Abstract: The resistance and resilience of perennial grasses and a small shrub to a natural disturbance (drought) were measured on stress gradients that were produced by domestic livestock in desert grassland ecosystems. Both survivorship of grasses and a sub-shrub (Gutierrezia sarothrae) during a drought (a measure of resistance) and re-establishment of plant cover following a drought (a measure of resilience) were reduced in the intensel stressed ecosystems in comparison to the lightly stressed ecosystems. The compromise of the resistance and resilience characteristics of an ecosystem can be used as a "fitness" test for the health of ecosystems. Fitness tests can provide early warning of ecosystem degeneration and allow intervention to reduce or eliminate anthropogenic stress on the ecosystems.