Experimental definition of resilience for state-and-transition models

TitleExperimental definition of resilience for state-and-transition models
Publication TypeConference Paper
Year of Publication2004
AuthorsHerrick JE, Belnap J, Bestelmeyer B, Bird S., Brown J., Havstad K, Tugel A.J., Van Zee JW
Conference Name57th Annual Meeting, Society for Range Management
Date PublishedJanuary 24-30, 2
Conference LocationSalt Lake City, UT
ARIS Log Number163132
Keywordsdegradation, models, resilience, state-and-transition
AbstractLimited management resources must increasingly be targeted to those parts of the landscape that have the greatest degradation risk and recovery potential. State and transition models have the potential tohelp identify these areas. Effective application of these models requires an understanding of the ecological properties and processes that determine resistance to change and resilience (capacity for recovery). Few data are currently available. In 1997 we established a long-term landscape-scale experiment designed to (1) identify resilience indicators based on relative recovery rates for different soil and vegetation indicators, and (2) determine the extent to which these relationships can be generalized across soils. Three types of disturbance (ORV tracks and trampling by humans and horses) were applied to five soils in southern New Mexico. Response variables included vegetation and lichen cover and composition, soil aggregate stability, soil surface roughness, infiltration capacity and penetrometer resistance. Both resistance and resilience varied with both disturbance and soil type. Vegetation indicators generally showed lower resistance (greater change) and higher resilience (more rapid recovery) during the first 6 years of the study than the soil indicators for most disturbance and soil types. These results suggest that soil indicators may reveal long-term disturbance effects that are not reflected in short-term vegetation responses. Both the long-term, cumulative effects of soil property changes on subsequent resistance and resilience and the role of contiguous site effects need to be considered in the development state and transition models.