2009 Research Highlights
Modeling uncertainty in forest ecosystem risk assessments
Researchers with the Eastern Forest Environmental Threat Assessment Center have worked with collaborators from the Canadian Forest Service and U.S. Forest Service Forest Health Technology Enterprise Team to adapt a generic bioeconomic modeling framework for examining pest invasions through time—with sirex woodwasp (Sirex noctilio) in eastern North America as a specific example—for the purpose of mapping risk (i.e., probability of invasion) and associated output uncertainties. Instead of generating separate risk mapping products (risk of introduction, risk of establishment, etc.), maps integrating the various stages of invasion (introduction, spread, establishment) into a single spatial output have been created. Using thousands of repeated replications, maps of invasion probabilities were projected 30 years into the future, along with associated maps of output uncertainty.
In subsequent work with other collaborators, the researchers have analyzed the impacts of uncertainties in key model assumptions on the pest risk map outputs. These analyses can support the selection of a management decision (e.g., a survey network derived from a pest risk map) that is most robust to uncertainty. Currently, the researchers are examining the trade-off between robustness to uncertainty and opportuneness, which is the possibility that a certain level of uncertainty in a risk model may enable “windfall” success (e.g., unanticipated and timely detections of an invasive pest). In addition, they are analyzing methods to better represent human-assisted spread in pest risk modeling/mapping contexts.
Contact: Frank Koch, Forest Health Monitoring Research Team, (919) 549-4006, frank.h.koch@usda.gov
Partners: North Carolina State University; USDA Forest Service Southern Research Station
