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Pacific Northwest Research Station

Pacific Northwest Research Station
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2011 Watershed Health

Key Findings and Products

The number of Chinook salmon and the size of steelhead trout increased in areas where in-stream habitat restoration efforts occurred in the upper Columbia River basin.

Long-term trends in temperature of western North American streams show both cooling and warming trends.

Everyday effects of vegetation on soil carbon loss may be as important as wildfire to carbon budgets.



In-stream restoration efforts benefit Chinook salmon and steelhead trout


Chinook salmon (Photo by U.S. Fish and Wildlife Service).Station scientists and cooperators evaluated the effectiveness of in-stream habitat restoration structures designed to enhance rearing habitat for juvenile salmonids. Habitat restoration structures consisted of engineered logjams and rock barbs extending from streambanks in the Entiat River watershed of the upper Columbia River basin. The researchers found that the number of juvenile fish from a threatened run of Chinook salmon were greater in microhabitats with restoration structures compared to microhabitats without the structures. Steelhead trout, although less abundant in restored microhabitats, possibly because of competition from Chinook salmon, showed faster growth rates compared to steelhead trout in untreated microhabitats.

The information is being used by restoration planners and by a larger monitoring program to further inform the design and implementation of additional restoration structures in the same watershed and in other watersheds throughout the upper Columbia River basin.

Contact: Karl Polivka,, Land and Watershed Management Program

Partners: Bonneville Power Administration; Cascadia Conservation District; National Marine Fisheries Service, Integrated Status and Effectiveness Monitoring Program


Scientist develop sampling and modeling tools to characterize microclimates in riparian areas

Scientists develop sampling and modeling tools to characterize microclimates in riparian areas Pro viding high-quality habitat for fish, amphibians, and other aquatic and riparian organisms is one management objective for headwater forests in the Pacific Northwest. The compatibility of timber harvest or other vegetation manipulations with quality riparian and aquatic habitat is often contingent on the effects these disturbances may have on riparian microclimate. Microclimate changes with distance from the streams. The ability to predict this variation and the influences of upslope harvesting and riparian buffers is important when designing management and monitoring strategies that will provide quality aquatic and riparian habitats while affording opportunities for the production of wood and other ecosystem services.

Microclimate data can be difficult and expensive to collect, so in this study, efficient sampling strategies were developed to account for the spatial variation in riparian forest structure and its influence on microclimate. Understory air temperature was then modeled based on topographic and forest structure. With increasing availability of remotely sensed forest structure data, this type of modeling may prove an efficient way to indirectly monitor microclimate attributes and to incorporate those attributes into forest management planning tools.

The modeling efforts have yielded insights to the relative accuracy and bias of alternative modeling approaches. Near-term utility is emerging in discussions among land managers and regulatory entities about the width of riparian buffers needed to mitigate potential effects of upslope harvest on the warming of air near streams and stream temperatures.

Contact: Paul D. Anderson,, Land and Watershed Management Program

Partners: Oregon State University, USDI Bureau of Land Management, U.S. Geological Survey


Alternative buffer designs influence abundance of small mammals along headwater streams


A fixed-width riparian buffer zone with upland timber harvest (Photo by Martin Raphael).Under the Northwest Forest Plan, all streams on federal land are protected by buffer zones intended to protect riparian and stream ecosystems from logging effects and other human disturbances. Different rules apply to state and private land, however. In Washington state, headwater streams in state and private industrial forests generally are less protected than those on federal land. This discrepancy has led to debate over how much protection fishless headwater streams should receive during logging. To find middle ground, station scientists worked with the Washington Department of Natural Resources (DNR) to evaluate alternative buffering strategies.

The scientists found that several small mammal species responded differently to different buffer widths following logging. The northwestern deer mouse declined in all treatments compared to unlogged drainages, while more creeping vole, southern red-backed vole, and Townsend’s chipmunk were found after logging in all buffer treatments. Relative to the unlogged drainages, the overall diversity and total abundance of small mammals did not change significantly following logging in any of the treatments.

These findings support the development of a long-term headwater stream conservation strategy for the DNR and the proposed adaptive management strategy for western Washington.

Contact: Martin Raphael,, and Randall Wilk,, Ecological Process and Function Program

Partner: Washington State Department of Natural Resources


Practical management actions can minimize the effects of climate change on amphibians


In Seattle’s Cedar River Municipal Watershed, managers are placing logs perpendicular to pond shorelines to provide sheltered routes for young frogs leaving the water to disperse across the land (Photo by Sally Nickelson).Leading the world campaign to develop practical tools to guard species from the adverse effects of climate change, an ad hoc group of international amphibian experts have compiled innovative examples of habitat protection and mitigation to preserve amphibian species across habitats in several nations. These examples fall into three categories: installation of microclimate and microhabitat refugia, enhancement of breeding sites, and manipulation of water or hydroperiods. Water and temperature management approaches are critical for this taxon. Microclimate mitigation tools include creating riparian buffers, restoring stream and pond habitat, and managing for down wood. The group’s products aim to bridge science and management, resulting in “adaptation management” approaches for amphibians and climate change.

Research and management agencies around the world are using these practical conservation ideas to take action. To share this information widely, the group maintains a Web page that includes a showcase of innovations and a list of new programs for conserving the rarest species.

For more information:

Contact: Dede Olson,, Land and Watershed Management Program

Partners: Department of Climate Change, Canberra ACT, Australia; James Cook University of North Queensland, Australia; University of Queensland, Australia; Griffith University, Gold Coast Campus, Australia; The University of Newcastle, Australia; University of Kent, Canterbury, United Kingdom; Universidade do Estado do Rio de Janeiro, Brazil; University of Helsinki, Finland; Pontificia Universidad Católica del Ecuador; University of Otago, New Zealand; EcoGecko Consultants, New Zealand; Florida International University; University of Washington; U.S. Geological Survey; Aldo Leopold Wilderness Research Institute


Stream gravel bars can be a nitrate source or sink depending on time it takes for water to move through them


Gravel bars can influence water temperature and water quality. Clackamas River, Oregon (Photo by Portland General Electric).Excess nitrogen stemming from human activities is a common water pollutant. Fertilizer runoff, sewage, and fossil fuel emissions all contain nitrogen that often ends up in streams. But aquatic systems are natural filters, able to process and remove some nitrogen. Fully understanding the denitrification process will help efforts to improve water quality.

Station scientists used a stable isotope tracer to track the movement and transformation of nitrate nitrogen in stream water flowing through a 14-foot gravel bar of an upland agricultural stream in the Willamette Valley, Oregon. Dissolved organic carbon and oxygen were used up quickly by microorganisms where stream water entered the head of the gravel bar, leading to initial increases in nitrate and ammonia concentrations. Further into the gravel bar, where travel times exceeded 7 hours, the scientists observed a net loss of nitrate to denitrification. This suggests that gravel bars could be net sources of nitrate to streams wherever travel times were short, but with longer travel times, denitrification will make gravel bars net sinks of nitrate to streams.

This study provides detailed understanding of the processes that control water quality, especially the processes that remove nitrate from nitrogenpolluted streams.

Contact: Steve Wondzell,, Land and Watershed Management Program

Partner: Oregon State University


Hillslope hydrologic connectivity controls riparian groundwater turnover


Sandy River, Oregon (Photo by Hemstrom).Hydrologic connectivity between uplands and near-stream riparian zones is essential for the export of water, nutrients, and other solutes from watersheds. However, our current understanding of the role of riparian zones in buffering watershedscale export of water and solutes is limited. To learn more about these processes, station scientists and collaborators compared the turnover time for shallow groundwater in riparian areas along four well transects in the Tenderfoot Creek Experimental Forest, Montana. They found that where hillslopes were large and riparian areas were small, hillslope water flowed through the riparian zone so that hillslope and riparian zone water were chemically similar. Conversely, where riparian zones were large relative to the size of the adjacent hillslope, water in the riparian zone was chemically distinct from hillslope-source water. These observations suggest that the relative sizes and spatial arrangement of hillslopes and riparian zones along a stream network is a primary control on the export of water and solutes from watersheds.

This export versus retention of solutes is critically important to stream ecosystem processes determining attributes such as ecosystem productivity and the ability of riparian zones to buffer streams from inputs that could alter water quality.

Contact: Steve Wondzell,, Land and Watershed Management Program

Partners: Montana State University, Pennsylvania State University, U.S. Geological Survey


Novel modeling effort links land use, disturbance, and riparian and aquatic habitats across large landscapes


Interactions between land use and ecosystem change are complex, especially in riparian zones. To date, few models are available to project the influence of alternative land use practices, natural disturbance, and plant succession on the likely future conditions of riparian zones and aquatic habitats across large landscapes.

Station researchers used a state-and-transition framework to model the effects of various management and restoration practices on conditions of riparian forests, channel morphology, and salmonid habitat. These models incorporate the effects of plant succession, natural disturbances such as fire or native ungulate browsing, management, and restoration practices. Researchers used the models to analyze habitat suitability rankings for two watersheds: the upper Middle Fork John Day River and the Wilson River, Oregon. They found that efforts to improve habitat for anadromous fish in the Middle Fork John Day Basin will likely require considerable work on in-stream conditions, not just management of the adjacent terrestrial and riparian vegetation.

Contact: Steve Wondzell,, Land and Watershed Management Program; Miles Hemstrom,, Focused Science Delivery Program


Decision-support systems developed to assess vulnerability and impacts of sulfur deposition across southern Appalachia


Decision support interprets long-term ecosystem effects of atmospheric sulfur deposition in the southern Appalachian region.The Environmental Protection Agency (EPA) and federal land management agencies are concerned with the health of aquatic ecosystems in the southern Appalachian Mountains. Acid rain and dry acidic deposition has increased the sulfate concentration in many Appalachian streams. Coalfired electric generating facilities, cars, and factories are the main sources of human-caused sulfur emissions.

A large water-sampling network was built in the region over the last few decades, but locations of sampling sites historically were highly biased toward watersheds with high sulfur depositions. Station scientists worked to develop statistical methods that overcame sampling biases and allowed accurate predictions of spatial variables required to assess vulnerability of ecosystems and aquatic biota to atmospheric sulfur deposition across the region. Their results were used to develop a decision-support system of immediate practical value to regional land managers, regulators, and policymakers with the Forest Service, National Park Service, and EPA.

A second decision-support system was developed to predict ecological and biotic impacts of atmospheric sulfur deposition across the southern Appalachian region. It can be used to prioritize watersheds for restoration and protection activities. Policymakers in the region can use the same system to explore the biological and ecosystem implications of alternative sulfur emission scenarios.

Contact: Paul Hessburg,, and Keith Reynolds,, Ecological Process and Function Program

Partners: E&S Environmental Services, Environmental Protection Agency, University of Virginia, USDA Forest Service Southern Region


Connections between air and stream temperature more complex than previously thought


Recent warming of the terrestrial climate in most parts of the world has motivated concern about corresponding increases in water temperature. Based on observed climate trends in the Pacific Northwest, scientists expected to find warmer streams and increasing temperature variability over time. However, they found as many cooling as warming trends in 18 reference streams across western North America. Winter minimums have been increasing, but summer maximums less so. Scientists compared the reference streams with 45 streams that have been more influenced by humans. The temperatures during the past two decades show mostly cooling trends in minimally human-influenced sites, whereas more humaninfluenced systems showed mixed responses. The scientists also noted a lack of coherence between air temperature, stream temperature, and flow, which may be related to complex and lagged interactions among nonclimate and climate variables. These findings inform climate researchers as well as state and federal resource managers about temporal trends in stream temperature dynamics.

Contact: Sherri Johnson,, Ecological Process and Function Program

Partners: Oregon State University, U.S. Geological Survey Forest and Rangeland Ecosystem Science Center


Soil respiration may influence carbon budgets as much as wildfire


Field crew learn how to conduct postfire soil surveys (Photo by Jon Williams).Fire intensity influences how much soil carbon is released into the atmosphere. Researchers found that intense wildfire associated with high tree mortality induced losses of soil carbon about twice that of lower intensity wildfire and fires set as a backburn. Prescribed fire resulted in about half as much lost soil carbon when compared to intense and moderate wildfire.

In unburned Douglas-fir plantations, however, carbon lost over 11 years through soil respiration had an extrapolated rate equivalent to an intense wildfire every 30 years, suggesting that day-in, dayout vegetation effects on soil carbon are potentially as or more important than wildfire. Soil respiration is a key measurement in the carbon budget. Researchers have used this data to develop a conceptual model of effects of management on carbon stocks. This model also points out that shrubs have greater potential to increase soil carbon when leaf areas are similar to trees because shrubs have less capability to store carbon above ground.

Improved understanding of the effects of natural disturbance and forest management on carbon budgets will allow land managers to refine estimates of a forest’s potential to mitigate climate change.

Contact: Bernard Bormann,, Land and Watershed Management Program

Partners: Oregon State University; Washington Department of Natural Resources Olympic Experimental State Forest; Western Washington State University; USDA Forest Service Rogue River–Siskiyou National Forest, Siuslaw National Forest, Willamette National Forest; USDA Forest Service Pacific Northwest Region Regional Climate Change Program, Regional Ecology Program, Regional Soils Program


Greater demand for bioenergy could lead to less forest land, more cropland in Midwest

Land use in the United States is influenced by many economic and social factors. One of the most important recent influences on land use in the United States has been the increasing use of corn-based ethanol in bioenergy production. High energy prices have sparked substantial growth in ethanol production and demand for corn, which could lead to loss of forests as landowners shift to agricultural uses.

Station scientists explored the relationship between land use and aesthetic or environmental values for forest land in Ohio, Indiana, and Illinois. Results suggest that as population density increases, desire for aesthetic amenities associated with open space or recreation could potentially lead to more forest land, relative to cropland. With a higher emphasis on bioenergy, however, a dramatically different future is presented, in which large areas of forest land are lost in the next 40 years.

Contact: Ralph Alig,, Goods, Services, and Values Program


US Forest Service - Pacific Northwest Research Station
Last Modified: Tuesday,18November2014 at14:53:04CST

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