Accounting for Spatial and Temporal Variation in Macroinvertebrate Community Abundances When Measuring the Food Supply of Stream Salmonids

The goal of salmonid habitat monitoring programs is to measure habitat attributes linked to salmonid productivity based on protocols that have sufficient precision to detect environmental variation at relevant spatial and temporal scales. Benthic macroinvertebrate community composition often is evaluated as part of habitat monitoring and assessment protocols, despite a lack of direct relationships between benthic composition and salmonid production. Macroinvertebrate drift provides a direct measure of the food resources available to stream salmonids, but drift is rarely evaluated as part of habitat monitoring protocols. This reluctance may stem from the complex spatial and temporal variability inherent in macroinvertebrate drift abundances and an assumed inability to obtain precise estimates of drift abundance at relevant spatial and temporal scales. We evaluated an extensive set of paired drift and benthic macroinvertebrate samples to characterize variation in the biomass and density (i.e., counts) of macroinvertebrate samples across a hierarchy of spatial and temporal scales. Results suggest that estimates of total drift biomass may offer the most precise approach for detecting differences in salmonid food availability among stream reaches and, thus, may be more appropriate than benthic sampling for incorporation into salmonid habitat monitoring programs

Beaver and Aspen: Synergy Among Keystone Species

In the West, climate change is likely to increase the frequency, intensity, and duration of drought. Restoration of soils and water storage capacity can help create resilient uplands and riverscapes (i.e., streams and the valley bottoms). Over the past two centuries, common land uses, the removal of beaver and wood, straightening of streams, and damage to riparian areas have created simplified, structurally starved, riverscapes. Degraded streams are very efficient at transporting water, sediment, and nutrients downstream. Aspen forests are also biological hotspots that have been degraded by past land uses such as overbrowsing ungulates, land clearing, fire suppression, and outright removal in favor of timber species. Loss of riverscape and aspen habitats has a disproportionate impact on biodiversity and landscape resilience. When aspen occur in or near riverscapes they are a preferred food and building material for beavers. Beaver, in-turn, can stimulate aspen regeneration, both through cutting and restoring hydrologic function in riparian areas. Adding beavers can reinstate riparian processes, increase aspen growth and diversity that extends to uplands, and buffer ecosystem sensitivity to extended drought

The Blurred Line Between Form and Process: A Comparison of Stream Channel Classification Frameworks

Stream classification provides a means to understand the diversity and distribution of channels and floodplains that occur across a landscape while identifying links between geomorphic form and process. Accordingly, stream classification is frequently employed as a watershed planning, management, and restoration tool. At the same time, there has been intense debate and criticism of particular frameworks, on the grounds that these frameworks classify stream reaches based largely on their physical form, rather than direct measurements of their component hydrogeomorphic processes. Despite this debate surrounding stream classifications, and their ongoing use in watershed management, direct comparisons of channel classification frameworks are rare. Here we implement four stream classification frameworks and explore the degree to which each make inferences about hydrogeomorphic process from channel form within the Middle Fork John Day Basin, a watershed of high conservation interest within the Columbia River Basin, U.S.A. We compare the results of the River Styles Framework, Natural Channel Classification, Rosgen Classification System, and a channel form-based statistical classification at 33 field-monitored sites. We found that the four frameworks consistently classified reach types into similar groups based on each reach or segment’s dominant hydrogeomorphic elements. Where classified channel types diverged, differences could be attributed to the (a) spatial scale of input data used, (b) the requisite metrics and their order in completing a framework’s decision tree and/or, (c) whether the framework attempts to classify current or historic channel form. Divergence in framework agreement was also observed at reaches where channel planform was decoupled from valley setting. Overall, the relative agreement between frameworks indicates that criticism of individual classifications for their use of form in grouping stream channels may be overstated. These form-based criticisms may also ignore the geomorphic tenet that channel form reflects formative hydrogeomorphic processes across a given landscape

An Economic Analysis of Lake Rehabilitation/Stabilization Projects: Mirror/Shadow Lakes and White Clay Lake

Ex ante analysis techniques are developed and applied to estimate the economic impacts of two lake water quality projects. The application of property value impacts and recreation demand models to one project produced an estimated flow of benefits nearly twice the costs. In the other project, because of low recreation use, the estimated benefits were barely half the costs

Empowerment Through Risk-Related Information: EPA\u27s Risk Screening Environmental Indicators Project

Working Paper 18Public access to information can drive change more effectively than regulations alone. Some regulatory agencies are now taking such an approach to advance their objectives. Right-to-know legislation, such as the Emergency Planning and Community Right-toKnow Act of 1986 (EPCRA), provides the basis for many of the U. S. Environmental Protection Agency’s (EPA) information disclosure initiatives. By requiring that the public be informed about releases of toxic chemicals in their communities, EPCRA— through its Toxics Release Inventory (TRI) in particular—can help to empower community residents, heighten industry accountability to the citizenry, and support efforts to ensure environmental justice