Treesearch

Land use and climate change are two key factors with the potential to affect stream conditions and fish habitat. Since the 1950s, Washington and Oregon have required forest practices designed to mitigate the effects of timber harvest on streams and fish. Yet questions remain about the extent to which these practices are effective. Add in the effects of climate change—lower summer flow and warmer water temperatures in some streams— and more questions arise. Scientists with the multipartner Trask Watershed Study set out to learn more about how the effects of climate change and timber...

The 80 official experimental forests and ranges (EFR) administered by the U.S. Forest Service have provided a remarkable collection of research findings over the last 100 years, helping the agency address information needs related to forest and rangeland management. Long-term data sets are one of the most significant contributions of the EFR system, in particular, the ongoing, long-term studies of the effects of a changing climate on natural resources, streamflow, vegetation, and biogeochemistry from experimental watersheds. These data are crucial for examining ecosystem services from...

growing body of literature examines the vulnerability, risk, resilience, and adaptation of indigenous peoples to climate change. This synthesis of literature brings together research pertaining to the impacts of climate change on sovereignty, culture, health, and economies that are currently being experienced by Alaska Native and American Indian tribes and other indigenous communities in the United States. The knowledge and science of how climate change impacts are affecting indigenous peoples contributes to the development of policies, plans, and programs for adapting to climate change...

Healthy Rivers Connect Humans and Ecosystems James Nash says he is part trout. Growing up on a ranch in the Wallowa Valley of northeast Oregon, he disappeared as often as he could to the banks of the Wallowa River, which runs for more than two miles through his family’s land. Once, while exploring the bottomland, he discovered some old ruts and grooves in the ground. “At first I didn’t know what they were,” he said. “But even as an 8-year-old, I could tell those channels would be better fishing.” He had found an old natural channel of the Wallowa River.

We describe the historical and current distribution of tree voles (Arborimus longicaudus; A. pomo) and compare the minimum density of trees with tree vole nests in different forest age-classes based on museum records, field notes of previous collectors, tree vole nest surveys conducted by federal agencies, and our field studies in Oregon and California. We conclude that tree voles are still fairly common in old forests within much of their historical range, but have become uncommon or rare in some areas as a result of fire and logging. Our analysis of food stored at red tree vole (A....

Mount St. Helens’ explosive eruption on May 18, 1980, was a pivotal moment in the field of disturbance ecology. The subsequent sustained, integrated research effort has shaped the development of volcano ecology, an emerging field of focused research. Excessive heat, burial, and impact force are some of the disturbance mechanisms following an eruption. They are also mechanisms of other, nonvolcanic disturbances. Studying ecosystem response to these disturbances across the gradient of disturbance intensity created by the 1980 eruption has revealed lessons relevant to the process of succession...

Past research has examined the effect of urban trees, and other vegetation, on stormwater runoff using hydrological models or small-scale experiments. However, there has been no statistical analysis of the influence of vegetation on runoff in an intact urban watershed, and it is not clear how results from small-scale studies scale up to the city level. Researchers address this gap in the literature by estimating random-effects regression models of the effect of trees and other vegetation on total runoff and peak runoff for a summer (15–16 June 2010) and a winter (18–19 December 2010) storm...

Future changes in society and climate are expected to affect wildfire activity in the south-eastern United States. The objective of this research was to understand how changes in both climate and society may affect wildfire in the coming decades.We estimated a three-stage statistical model of wildfire area burned by ecoregion province for lightning and human causes (1992–2010) based on precipitation, temperature, potential evapotranspiration, forest land use, human population and personal income. Estimated parameters from the statistical models were used to project wildfire area burned...

Effective conservation planning requires understanding and ranking threats to wildlife populations. We developed a Bayesian network model to evaluate the relative influence of environmental and anthropogenic stressors, and their mitigation, on the persistence of polar bears (Ursus maritimus). Overall sea ice conditions, affected by rising global temperatures, were the most influential determinant of population outcomes. Accordingly, unabated rise in atmospheric greenhouse gas (GHG) concentrations was the dominant influence leading to worsened population outcomes, with polar bears in three...

Using data from destructively sampled Douglas-fir and lodgepole pine trees, we evaluated the performance of regional volume and component biomass equations in terms of bias and RMSE. The volume and component biomass equations were calibrated using three different adjustment methods that used: (a) a correction factor based on ordinary least square regression through origin (OLS-RTO method); (b) a correction factor based on OLS with intercept (OLS-WI method); and, (c) an inverse approach. The regional volume equations performed fairly well and produced similar results as the locally fitted...