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Submitted to: Meeting Abstract
Publication Type: Abstract Only Publication Acceptance Date: 12/1/2003 Publication Date: 1/27/2004 Citation: Sheley, R.L. 2004. Revegetation: planning the end game before we start. Meeting Abstract . In: Science and Decision-Making in Biological Control of Weeds: A Conference on the Benefits and Risks of Biological Control. January 27-29, 2004, Denver, Colorado. Interpretive Summary: Technical Abstract: It is becoming increasingly clear that prescriptions for invasive weed control are not sustainable because they treat the symptoms of weeds, rather than their cause. Understanding the mechanisms of invasion resistance is central to developing sustainable invasive plant management programs. A generalized objective for ecologically based weed management is to develop and maintain healthy plant communities that are largely invasion resistant. A healthy, weed resistant plant community consists of diverse group of species that occupy most of the spatial and temporal niches. In several studies, we found that increasing species richness using species that are niche differentiated nearly prevented the invasion of rangeland by spotted knapweed. In a long-term companion study, we also found that increasing niche differentiated species richness enhanced desired species establishment and persistence when seeded on sites with a substantial spotted knapweed seed bank. In another study, seven major functional groups were selectively removed from an intact bluebunch wheatgrass/Idaho fescue habitat type to determine their role in resisting invasion. Spotted knapweed was seeded into each plot once the removal treatments had stabilized. Plots without plant removal had the lowest spotted knapweed density. Removing all forbs increased knapweed density about five times more than removing all grasses. I believe that sustainable weed management must focus on establishing and maintaining desired niche differentiated functional groups if they are to be sustainable. Establishing desired species in invasive plant dominated rangeland is expensive and the likelihood of success using current farming technology is low. We have enhanced the likelihood of successful restoration by using ecological theory to guide its implementation. Augmentative Restoration is a method for restoring weed infested rangeland to native plant communities where the heterogeneity in present successional processes are augmented by selectively repairing or replacing damaged or absent successional processes to direct plant communities on a desired trajectory. In each study, where the causes of plant community dynamics were addressed, establishment and maintenance of desired species was highest |
