Inventory and Survey Methods for Nonindigenous Plant Species (PDF)

Chapter 10 • Beyond Inventory/Survey and Monitoring: Risk Assessment and Managementcan help identify which NIS require the most attention andwhat areas are most at risk to new invasions. The greatestadvantage of NIS risk assessment is that it provides aproactive approach for management of NIS. The use of riskassessments allows:• Proactive and preventative management, not just reactiveresponse to NIS invasions• Assessment of NIS management priorities and costs• Production of maps that assist in the efficiency andeffectiveness of land management over time• Assessment of large landscapes for NIS at a fraction ofthe costs of complete inventory or systematic survey andmonitoring proceduresHowever, despite their promise, NIS risk assessments areonly in the developmental stage, and usable, verified riskassessments are in their infancy. Several conceptual andpractical challenges, as listed below, must be addressedbefore NIS risk assessments become a reliable tool for landmanagers and policy makers:• Assessments need to be general enough to predict risk formany NIS, but adaptable enough to change criteria fordifferent species.• Resolution of the information must be considered: scalestoo coarse for application and too fine for use in detectinginvasions within the landscape are of limited use to landmanagers.• Biological information that is needed to parameterize riskassessments is lacking for many NIS. For example, informationon NIS habitat suitability, long- and short-distancedispersal mechanisms, relationships with disturbanceagents, and ecological and socioeconomic impacts ofinvasion are needed.• GIS coverage on existing vegetation (i.e., not “potential”vegetation) is often absent or not recent, which can haveconsiderable impact on the quality of results.• Risk assessments are most effective when based oninformation from recent, in-depth NIS inventories orsurveys. Such activities can be time consuming andexpensive and are lacking for many managed landscapes.However, previous chapters in this book suggest effectiveinventory/survey methods.AcknowledgmentsThis research was sponsored by the USDA Forest ServiceRegion 6, Special Technology Development Program, andthrough a Joint Venture Agreement between Oregon StateUniversity and the USDA Forest Service, Pacific NorthwestForest Research Station.ReferencesEndress, B. A. and C. G. Parks. 2004. Element Stewardship Abstract (ESA)for Potentilla recta L. Sulfur cinquefoil. Wildland Invasive Species Team,The Nature Conservancy. http://tncweeds.ucdavis.edu/esadocs/poterect.html.Mantas, M. 2003. Evaluating Risk to Native Plant Communities fromSelected Exotic Plant Species (draft report). National Fire Plan CohesiveStrategy Team, Northern Region. http://www.fs.fed.us/r1/cohesive_strategy/data/weeds.htm.Rice, P. M. 1999. Sulfur cinquefoil. Pages 382-387 in R. L. Sheley and J. K.Petroff, eds. Biology and Management of Noxious Rangeland Weeds.Corvallis, OR: Oregon State University Press.Zouhar, K. 2003. Potentilla recta. In Fire Effects Information System. U.S.Department of Agriculture, Forest Service, Rocky Mountain ResearchStation, Fire Sciences Laboratory. http://www.fs.fed.us/database/feis/plants/forb/potrec/index.html.Many of these challenges can be overcome by additionalwork and research. Without doubt, NIS risk assessmentshold great promise for enabling land managers to proactivelyaddress NIS problems and increase the effectiveness ofprevention, control, eradication, and restoration efforts in anefficient, cost-effective manner.74Inventory and Survey Methods for Nonindigenous Plant Species