Treesearch

Water temperature influences virtually every biotic component of stream ecosystems. Not surprisingly, increased summer temperatures in streams with coldwater species of fish such as salmon and trout have become a topic of concern regionally and internationally. Although stream temperature has been studied for many years, controversy continues over the relative influences of shade, air temperature, and substrate on temperature dynamics.Researchers at the PNW Station have recently conducted experiments and calculated heat budgets that itemize the relative influence of several factors on the...

There is little question that global warming would increase the risk of wildfires by drying out vegetation and stirring the winds that spread fire. Until recently, however, land managers were unable to formulate appropriate responses because the spatial scales of predictions were far too coarse. Current research being done at the PNW Research Station in Portland, Oregon, has offered the first geographically specific estimate of the potential effect of climate change on wildfires in the United States. Simulations for three multicounty areas in northern California under a climate change...

Policies to achieve biodiversity goals have been implemented across many different forest ownerships in the last 10 years. Surprisingly, little research has been done to examine how well those policies might achieve their goals, how they might change landscapes in the future, and how the policies affecting different owners add up to a total picture of forest biodiversity in a large multiowner landscape.To fill this void, the Coastal Landscape Analysis and Modeling Study (CLAMS), a multidisciplinary research project centered at the Pacific Northwest (PNW) Research Station in Corvallis,...

Nineteen scientists from leading research institutes in the United States collaborated to estimate how California’s environment and economy would respond to global climate change. A scientist from the PNW Research Station led efforts to estimate effects on vegetation, carbon, and fire. To quantify the range of the possible effects of climate change over the next century, researchers used state-of-the-art climate change simulations coupled with a dynamic vegetation model to gauge sensitivity of natural ecosystems in California under several climate scenarios. The results suggest that...

Conserving biodiversity in the Oregon Coast Range requires tradeoffs. Policymakers must consider both the costs and benefits of new conservation programs. During this appraisal process, the costs, in terms of economic activity forgone, are often easier to quantify than the benefits. We all know that biodiversity is valuable, but how does its value compare to other important resources and services?Researchers at the Pacific Northwest (PNW) Research Station in Corvallis, Oregon, mailed out thousands of surveys to measure the public's willingness to pay for conservation in the Oregon Coast...

In response to the highly uncertain outcomes inherent in forest management, “options forestry” has been introduced as a novel approach that includes an honest appraisal of uncertainties and learning as a specific objective. The strategy is unique in that it uses a variety of management pathways, all designed to reach the same goal, and structures them in a rigorous statistical design to reduce and spread the risks associated with failure.In the first application of options forestry, researchers at the PNW Station collaborated with managers at the Siuslaw National Forest to create the Five...

Overtrapping of fishers in the early 1900s, combined with widespread habitat loss from clearcut logging, has resulted in the extirpation of this forest-dwelling carnivore throughout much of its former range in the Western United States. Poor dispersal abilities, low-density populations, and low reproductive rates all hinder the recovery of this little-known relative of weasels, minks, and otters. In the Pacific Northwest, the fisher occupies dense, lower elevation coniferous forests, and uses large live trees, snags, and logs for denning and resting. In the last 15 years, three petitions...

About 75,000 irrigation, flood control, and hydropower dams in the United States are aging, deteriorating, or have outlived their useful lives and purposes. Not surprisingly, dam removal is emerging as both a challenge and opportunity for river management and research. Scientists at the PNW Research Station in Corvallis, Oregon, are using scale models and monitoring actual dam removals to predict the response of rivers to various dam removal scenarios.Of particular concern is the fate of sediments that have accumulated behind the dams. Reservoirs created by small dams are often completely...

This book is about the status and future of the sagebrush ecosystem and its dependent species. While the ecosystem remains large, it is not healthy. In fact, some have said it is dying-albeit a slow death, and one caused by thousands of small insults to its integrity. Because the insults-better known as human land uses-are many and varied, with no single use to which full blame can be assigned, the solutions likewise are many and varied. Therein lies the problem: to maintain the ecosystem and its many species of concern will require monumental changes in management, and those changes must...

Wildland fire is an important disturbance agent in forests of the American Northwest. Historical fire suppression efforts have contributed to an accumulation of fuels in many Northwestern forests and may result in more frequent and/or more severe wildfire events. Here we investigate the extent to which atmospheric and climatic variability may contribute to variability in annual area burned on 20 National Forests in Washington, Oregon, and Idaho. Empirical orthogonal function (EOF) analysis was used to identify coherent patterns in area burned by wildfire in the Pacific Northwest. Anomaly...