The objectives of the project include:

Objective 1: Develop and test methods for monitoring subcatchment and stream condition of low-order drainages.  
Rationale: The productivity of a stream is a reflection of the health and condition of the watershed it drains.  By measuring detritus and invertebrate transport from headwaters (surrogates of headwater production) at a point along the length of a stream, we can assess the level of productivity, and therefore health and condition of a headwater subcatchment upstream of the sampling site.  We intend to test methods in the Wenatchee River Basin for monitoring headwater subcatchment condition that were developed by Wipfli and Gregovich (2002) for southeastern Alaska streams.  Data suggest this technique holds promise as a surrogate of headwater subcatchment productivity, can serve as a tool for assessing the cumulative impacts of multiple stressors in sub... catchments, and can be used as an indicator of watershed condition and health.

Objective 2: Determine the effects of land-use and vegetation cover on biological productivity of headwater subcatchments.
Rationale: Stream productivity and community structure are tightly linked to riparian zones and surrounding vegetation.  Land-use and watershed condition affect riparian forest conditions and functionality, which in turn affects the biological productivity of associated aquatic ecosystems.  We will show that we can use the methodologies developed under Objective 1 to directly monitor the effects of land-use and vegetation cover on the biological productivity of headwater subcatchments. If we are successful, this monitoring tool will provide a simple and relatively cost-effective technique for long-term monitoring of headwater subcatchments by management agencies.

Objective 3: Link land use, vegetation cover, and watershed condition of fishless subcatchments to fish communities in downstream habitats.
Rationale: Headwater channels can be important sources of nutrients and carbon for fish-bearing habitats in lower parts of drainages (Wipfli and Gregovich 2002).  Transport of food to fish-bearing food webs may therefore have profound effects on fish condition in lower reaches.  We propose to use fish diet, lipid and isotope levels as indicators of fish condition to demonstrate the ecological connectedness between upland fishless habitats and lower fish-bearing habitats (via the food that these subcatchments deliver to fish).  We also propose to use this approach to facilitate the connection between land-use and vegetation cover condition in headwater forests with watershed condition downstream, particularly for anadromous salmonids.

Background

Low-order streams (= 1st order; typically fishless streams) comprise more than 80% of drainage networks, yet very little is known about the role they play in affecting downstream habitats and communities (Benda and Dunne 1997, Gomi et al. 2002).  Wipfli and Gregovich (2002) found that small fishless streams can be important energy sources for downstream food webs in salmonid ecosystems in southeastern Alaska, transporting invertebrates and organic material produced in headwaters environments to habitats lower in the drainage that contain fish.  Further, vegetation cover apparently has a large impact on carbon (food) production in these small drainages, ultimately influencing the amount of prey and organic detritus that gets transported downstream to fish-bearing food webs (Piccolo and Wipfli 2002, Wipfli and Musslewhite 2004).
Understanding the ecological function of these headwater channels and associated subcatchments, and developing monitoring tools for assessing their condition is crucial for a broader understanding of basin-wide watershed condition, and for restoration effectiveness monitoring.  Wipfli and Gregovich (2002) developed a technique in southeastern Alaska that could prove very effective for assessing the biological condition of these small drainages, and therefore the cumulative effects of land use and watershed condition.  We intend to link watershed condition with stream productivity, food resources for fishes, and ultimately fish condition.  Our approach seeks to combine current approaches in aquatic ecology to determine the combined effect of land-use practices and climatic variation on productivity of resources relevant to the condition of fishes in the Interior Columbia River Basin (ICRB) at the whole-watershed scale.  Changes in the biomass and taxonomic composition of the standing crop of macroinvertebrate resources, the presence of headwater-derived resources in the diets of fish and differences in fish condition should demonstrate the contribution of headwater streams to fish assemblages.
This work represents an opportunity to test and develop a novel, innovative approach for watershed assessment by directly monitoring the productivity of food webs, and indirectly all the cumulative processes and factors (e.g., organic matter load and dynamics, inorganic sediment dynamics, flow regime, light, allochthonous inputs, , water temperature, land-use, etc.) that drive it.  It is important to emphasize that this work focuses on food web productivity of low order streams as a means for testing and developing a new tool for monitoring watershed condition and restoration effectiveness.  This approach is novel for three reasons: (i) food web monitoring gets right to the bottom line and integrates the stressors, processes, and conditions that ultimately drive these ecosystems; (ii) it directly links headwater condition and downstream fish condtion; (iii) these low order watersheds comprise over 80% of typical drainage networks, therefore in aggregation have great potential to influence salmonid habitats downstream; and (iv) monitoring in these low order watersheds has been historically ignored.  

Role of the University of Alaska Fairbanks (UAF) Team:
Overview:  UAF is working cooperatively with scientists from the Wenatchee Aquatic and Land Interactions (WALI) team (contract #24725) to complete the goals stated above.  BPA initiated the research program "Integrated Status and Effectiveness Monitoring" in 2003 to assess the status of aquatic resources and fisheries in the Wenatchee sub-basin of the Upper Columbia River Watershed.  Amounts of organic, inorganic, and invertebrate subsidies derived from headwater streams could strongly affect downstream ecosystems in the Wenatchee sub-basin: The close collaboration between the UAF and WALI teams represents a unique opportunity to determine how these subsidies vary from the reach to landscape scale.

Dr. Mark Wipfli is a Co-Principal Investigator on the project and in conjunction with Dr. Chris Binckley (Post doctoral fellow - UAF) and Bruce Medhurst (MS student UAF), are leading the headwater monitoring portions of the study.  These include:  (1) Quantifying productivity of fishless headwater habitats across land-use and climatic gradients.  The methods developed by Wipfli and Gregovich (2002) in southeastern Alaska should be transferrable to the ICRB for assessing the biological condition of these headwater habitats.  Furthermore, these headwater energy and nutrient subsides could affect fish condition, thus (2) specific fish responses (e.g. lipid and isotope levels) resulting from headwater delivery will be quantified.   Show More