Location: Watershed Management ResearchTitle: Resilience to disturbance and resistance to alien grass invasions in the cold desert of western North America Author
Submitted to: Ecosystems
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/23/2013
Publication Date: 1/1/2014
Citation: Chambers, J.C., Bradley, B.B., D'Antonio, C., Germino, M.J., Grace, J.B., Hardegree, S.P., Miller, R.F., Pyke, D.A. 2014. Resilience to disturbance and resistance to alien grass invasions in the cold desert of western North America. Ecosystems. 17:360-375. Interpretive Summary: Invasive annual grasses have disrupted millions of hectares of rangeland in the Intermountain cold desert region of the United States. Land managers in this region believe that one of the most effective ways to manage potential or actual invasion by annual weeds is to maintain or restore native plant community resilience and resistance to invasion. While the concepts of resistance and resilience can be intuitively understood, it has proven difficult to implement these concepts by converting them into actual management actions. In this paper, we discuss how specific ecosystem processes are linked to resilience and resistance to invasion, and suggest ways in which these concepts can be used operationally for management. Linking these terms to the underlying ecological processes, and suggestions for specific management actions will significantly improve our ability to manage these lands for multiple resource values.
Technical Abstract: Alien grass invasions are resulting in ecosystem-level transformations of entire landscapes in arid and semi-arid ecosystems. The cold desert of western US is undergoing such a transformation, and is considered one of the most imperiled large ecosystems in the US. To address the rapid and complex changes occurring in cold desert ecosystems, management objectives often include attempting to increase resilience of the native ecosystems to stress and disturbance and/or resistance to invasion. While these goals are simple in concept, they are challenging in practice, and we are just beginning to develop the basis for operationalizing them. In this paper we address a linked series of questions on the ecosystem attributes and processes that determine resilience and resistance across large landscapes, the strategies that can be used for operationalizing these concepts, and the information and analytical methods that are needed to fully implement them. Cold desert ecosystems provide an excellent opportunity for examining these questions because they exhibit inherent differences in resilience to stress and disturbance and resistance to invasion over strong environmental/productivity gradients. In addition, the stresses and disturbances affecting these ecosystems have been well-studied as have the ecosystem attributes influencing the potential vs. actual distribution (i.e., fundamental vs. realized niche) of the primary invader, B. tectorum. Although our focus is on cold desert ecosystems of the western United States, we believe that the definitions and concepts in this paper have general applicability to other ecosystems experiencing annual grass invasions.