Pacific Southwest Research Station

Pacific Southwest Research Station
800 Buchanan Street
West Annex Building
Albany, CA 94710-0011

(510) 559-6300

Our mission is to gain a better understanding of the physical and biological processes that integrate terrestrial, riparian, and aquatic ecosystems at the watershed scale. To take an interdisciplinary approach to study the production and transport of watershed products (water, sediment, woody debris, nutrients, and heat) and their influence on physical and biological resources (such as water supply and fish populations). Using this improved understanding, to assist in the development of new management strategies for ecoscape management.

Problem Statements:
Because of the integrative nature of cumulative watershed impacts and the resulting need to approach the problem using a variety of closely inter-related studies at a variety of temporal and spatial scales, the problem area does not permit subdivision into distinct, individual problems. RWU-4351 has thus organized the Unit's research into a single problem.

Problem 1: A better understanding is needed of the interaction between watershed processes and downstream biological and physical resources.

We are engaged in two complementary approaches to understanding and addressing the problem of cumulative watershed impacts.

First, a variety of individual studies focus on poorly understood components of the flowchart shown in Figure 1. Some of these studies involve interdisciplinary collaboration either within the work unit or with outside cooperators, while others represent fundamental research within a particular discipline. These studies include hillslope process studies, which explore the influence of land-use activities on the generation of water, sediment and woody debris; product routing studies, which provide an understanding of how watershed products are conveyed to sensitive sites; and aquatic and riparian response studies, which investigate how biological and physical ecosystem components respond to changing conditions. In each case, both natural and disturbed systems need to be understood.

The second approach uses the results of multiple component studies to carry out integrative research at the scale of watersheds and river basins. At Caspar Creek Experimental watershed in California, for example, it is possible to perform treatment-response experiments at the scale of 4?km2 watersheds. At the same time, component studies in the watershed provide detailed information on hillslope processes, product routing, and ecosystem response. Controlled experiments are not feasible at the scale of river basins, so RWU-4351 is carrying out "forensic" integrative studies at this scale by using results of component studies to interpret existing evidence of system response to past land-use practices.
The two approaches are inextricably intertwined: results of the component studies provide the basis for the integrative studies, and results of the integrative studies define the components that require more intensive investigation.

Staffing:
4 Scientists: 4 permanent (4 full-time, 0 part-time, 0 seasonals with tour), 0 terms, 0 PostDocs, 0 temporaries, 0 etc.
20 Technical Support: 8 permanent (8 full-time, 0 part-time, 0 seasonals with tour), 4 terms, 0 PostDocs, 8 temporaries, 0 etc.
2.5 Administrative Support; 2.5 permanent (2.5 full-time, 0 part-time, 0 seasonals with tour), 0 terms, 0 PostDocs, 0 temporaries, 0 etc.

Funding Level: (Forest Service Research Funds at Congressional Appropriations Level; Other Forest Service funds…fire, S&PF, International program, etc.)

Outside Funding: (last 3 years amount of outside funds; Funding sources)
1999 2000 2001
$252,000 $170,000 $311,974

What results are your studies aiming for?
Results of these studies provide substantial benefits for management and regulatory agencies because of improved understanding of the extent to which land management activities, including timber harvest and road-building, are compatible with sustaining other resource values, such as water quality and quantity, and sensitive plants and animal species, including salmon and steelhead trout.

Notable Research Accomplishments and who is using it, in the last 5 years:
Industry and regulatory agencies have relied heavily on published results from experimental logging in the North Fork of Caspar Creek when preparing and evaluating management plans for industrial forest lands. More effective sampling methods will be utilized in monitoring plans designed to detect changes in turbidity and suspended sediment loads. For example, results from the Caspar Creek Experimental watershed studies are the basis for watershed analyses developed by Pacific Lumber Company for State and Federal regulatory agencies to meet the requirements of the HCP and cumulative effects analysis for the Headwaters Agreement.

At the request of various state and federal agencies, several methods of watershed analysis were reviewed and their strengths and weaknesses identified. Results of the review of the watershed analysis method proposed for use on state and private lands in California could lead to improvements in the design of the method and to more effective interfacing with similar work on federal lands, as implemented under the Northwest Forest Plan. Results of the review of a watershed analysis conducted under a bellwether Pacific Lumber Company HCP are being used by the National Marine Fisheries Service, the U.S. Fish and wildlife Service, the California Department of Fish and Game, and the North Coast Regional water Quality Control Board to design prescriptions for land use on lands covered by the HCP. Results are likely to lead to less expensive, more effective watershed analyses on these and other lands.

Research on invasive fishes in northwestern California contrasts the attributes of successful and unsuccessful introduced fishes, and identifies significant interactions among invasive species, native species, and habitat features in freshwater systems. The current and probable future distribution of an introduced species with significant effects on the diversity of native species may strongly influence decisions about appropriate locations and methods for ecosystem restoration. Such knowledge will help protect forest resources like salmon by identifying prospective detrimental invaders and characteristics of ecosystems that enhance the probability of invasion. Broad interest in the effects of introduced species among federal agencies and scientific societies reflects recognition of the disparity between our knowledge of the ecological roles of introduced species and their likely significance to the maintenance of ecosystems that support native taxa while providing essential goods and services.

Suction dredging for gold is common in many streams and rivers in western North America that support populations of salmonids. Although dredging and spawning usually do not happen at the same time, newly reported research indicates that at high flow there is significantly greater danger of scour in redds constructed on dredge tailings than in redds constructed on undisturbed spawning gravels. The hazard is apparently most acute for populations that spawn in the fall after dredging is over but before high scouring flows begin. The hazard can be reduced by requiring miners to redistribute tailings to restore natural channel topography. This research is being used by water quality, fishery, and reclamation agencies.

In many geologic terranes, soil erosion contributes large volumes of sandy material to stream channels, where it fills stream gravels inhabited by aquatic invertebrates, juvenile fish, and incubating fish embryos. This material moves swiftly through stream channels, and its abundance in streams is sensitive to annual changes in rates of input from the watershed. The supply of fine sediment in stream channels can be evaluated by focusing on its primary depositional sites-pools. More precisely, the fraction (V*) of the residual volume of pools filled with fine bed material can be measured by probing its thickness with a thin metal rod and measuring water depths during low flow. V* is gaining wide use nationally and internationally as a monitoring parameter. V* correlates with basin sediment yield, depending on the predominant rock type. It correlates well for rocks (weathered granite, sheared or poorly cemented sandstone, shale, and schist) that produce large fractions of sandy sediment as weathering products, but not for rocks (some metamorphic rocks, volcanics, and well-cemented sediments) that produce small fractions of sandy material. V* can also be correlated with diversity and biomass of aquatic invertebrates, and its influence on fish populations is being investigated. This research is being used by water quality, fishery, and reclamation agencies.

How do you communicate the knowledge and results of your research?
· Comprehensive Internet Web pages are maintained daily at http://www.rsl.psw.fs.fed.us
o Detailed description of research and staff
o Listing of all publications since 1965, with 310 publications available on-line
o 40 years of watershed data from Caspar Creek available on-line
o Real-time hydrologic and climatic data available on-line
· Publication of research results in books, journals, proceedings, and other technical reports
· Presentation of research results at local, national, and international meetings and workshops
· One-on-one consultations with research users and interested public

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