Author
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Davies, Kirk |
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JOHNSON, DUSTIN - OSU-EXTENSION BURNS OR |
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Submitted to: Invasive Species: Detection, Impact and Control
Publication Type: Book / Chapter Publication Acceptance Date: 4/24/2008 Publication Date: 5/1/2009 Citation: Davies, K.W., Johnson, D.D. 2009. Prevention: A Proactive Approach to the Control of Invasive Plants in Wildlands. p. 81-96. In: Wilcox, C.P. and R.B. Turpin (eds.). Invasive species: Detection, Impacts and Control. Nova Science Publishers, Inc., Hauppauge, NY. Interpretive Summary: Infestations of wildlands by invasive plants (weeds) can reduce forage production, decrease biodiversity, displace native vegetation, and alter ecosystem processes and functions. The traditional strategy of controlling established invasive plant infestations followed by restoration of native vegetation has proven to largely be ineffective. This approach often fails in its attempt to restore native plant communities and is too costly to apply at the scale required to have substantial effects. We suggest that a proactive approach with the objective of preventing new infestations and limiting the expansion of existing infestations is a more effective and efficient strategy for managing invasive plants in wildlands because it precludes the need for restoration. Successful strategies to prevent infestations of invasive plants should focus on: 1) limiting the dispersal of seeds (i.e. propagule pressure), 2) maintaining or increasing the ability of wildland plant communities to resist invasion (i.e. biotic resistance), and 3) systematically searching for and eradicating new infestations. Successful management of invasive plants in wildlands will require more efforts and resources directed at prevention. This task can be facilitated by more research developing and improving prevention strategies and demonstrating the effectiveness of prevention. This information is useful to land managers developing invasive plant management programs and to scientists investigating prevention tools and strategies. Technical Abstract: Infestations of wildlands by invasive plants can reduce resource productivity, decrease biodiversity, displace native vegetation, and alter ecosystem processes and functions. The traditional reactive strategy of controlling established invasive plant infestations followed by restoration of the native plant community has proven to largely be ineffective at reducing the spread and negative impacts of invasive plants. This approach often fails in its attempt to restore native plant communities and is too costly to apply at the scale required to have substantial effects. While large amounts of resources are intensively spent on efforts to restore a few infested wildlands, invasive plants continue to spread as emerging populations and expanding established infestations. A proactive approach with the objective of preventing new infestations and limiting the expansion of existing infestations is a more effective and efficient strategy for managing invasive plants in wildlands because it precludes the need for restoration. However, relatively few resources are being directed to prevent the spread of invasive species. Successful strategies to prevent infestations of invasive plants should focus on: 1) limiting the spatial dispersal of propagules (i.e. reducing propagule pressure), 2) maintaining or increasing the ability of wildland plant communities to resist invasion (i.e. biotic resistance), and 3) systematically searching for and eradicating new infestations. Propagule pressure and biotic resistance interact to determine wildland plant community invasibility. At low biotic resistance even a few propagules may result in successful invasion; however, as biotic resistance increases, greater propagule pressure is required for invasion. Thus, efforts aimed at decreasing invasive plant propagule pressure and increasing biotic resistance can greatly reduce new infestations. Systematically searching for and eradicating new infestations is a critical element of a successful prevention strategy, because uncontrollable events may still lead to new infestations. Successful management of invasive plants in wildlands will require more efforts and resources directed at prevention. This task can be facilitated by more research developing and improving prevention strategies and demonstrating the effectiveness of prevention. |
