Physical Sciences and Mathematics Commons^™

Herbicide Resistance: Challenges For Farmers And Implications For The Environment, George Frisvold, David E. Ervin

Economics Faculty Publications and Presentations

Genetically modified, herbicide resistant (HR) crops offer not only improved weed control, but also the potential to reduce soil erosion and fossil fuel use and to allow substitution toward less toxic or persistent herbicides. The widespread adoption of HR crops, however, has reduced the diversity of weed control tactics and increased ecological selection pressure for weeds resistant to dominant herbicides. This has led to a dramatic rise of HR weeds in many cropping systems. Resistant weeds threaten the sustainability of HR crops, pose environmental risks from alternative weed control practices, are altering public and private R&D programs, and necessitate new …

Experiential Knowledge And Interdisciplinary Approaches To Address Herbicide Resistance: Insights From Theory And Practice, David Shaw, David E. Ervin

Economics Faculty Publications and Presentations

The exponential increase in herbicide resistant weeds around the globe poses a “wicked problem” that resists solutions developed from disciplinary science (Ervin and Jussaume; Shaw). Traditonal voluntary education and technical assistance approaches have failed to stem the advance of resistance. Scholars and practitioners recognize that improved understanding of human behavior leading to more resistant weeds must provide the foundation of knowledge for innovating more effective approaches. Principles to negotiate progress on wicked problems stress interdisciplinary approaches that integrate frontier social and natural science concepts with stakeholder experiences to discover novel approaches (Sayer et al). Standard templates to address the problem …

Estimating The Recreational Value Of Portland’S Forest Park, Randall Bluffstone, Ryan Burchett, Kahtan Eiwaz, Emma Ingebretsen, Peter Schaffer, Steve Toth, Szeto Yan Weng, Jordan Drinkhouse, Dat Huynh, Charles Maxwell, Joel Schutte, Tiffany Tram, Thananan Yupparit

Economics Faculty Publications and Presentations

Using the travel cost method, this study estimates the per-trip value and total annual value of recreational visits to Portland’s Forest Park. Based on the opportunity cost of visitors’ time and the estimated costs of travel, we derive a demand function for visits to Forest Park on the assumption that visitors value their trips to Forest Park at least as highly as the alternative uses of their time and money. The Portland Parks and Recreation Department supplied survey data for 2277 Forest Park visitors, of which we use 1626 observations.

We find that a truncated negative binomial regression best fits …