Management for rehabilitation of degraded arid ecosystems

TitleManagement for rehabilitation of degraded arid ecosystems
Publication TypeConference Paper
Year of Publication1994
AuthorsHavstad K
Conference NameThe Wildlife Society Meeting
Date Published1994
AbstractManagement strategies for rangelands based on components of succession theory are too simplistic and ineffective. We are now developing more dynamic interpretations of rangelands that incorporate components of lag effects and threshold, importance of episodic events, and multiple stable states and trajectories of vegetation change. These models defy traditional approaches to management, especially regarding improvement of specific resource components. Coupled with increased regulatory restrictions and volatile economics, these new theories force us to revise both our approaches to management and our expectations for the resource. Often we must now admit that restoration, in its narrowest sense the complete return of a site to a pre-existing state, is not a feasible alternative. Our vegetative goals are more appropriately toward rehabilitation, defined as the repair of blocked or damaged ecosystem functions. In the Southwest, desert grasslands have shifted to shrub dominance due to one or more allogenic factors. However, shrub persistence in this region derives from autogenic factors. Our options for rehabilitating stable, shrub-dominated vegetative states are seriously limited, both ecologically and economically. Management efforts need to be directed toward areas that are either in transition or at critical thresholds. In these areas our management practices need to be minimal and silected for their ability to generate cascading effects post-treatment. We have these general tools, but they need to be linked with an ability to detect thresholds, and recognition (and agreement) of functions that need to be repaired.