This research was designed to broaden the understanding of how timber-harvest affects aquatic macroinvertebrates in perennial and intermittent headwater streams. This study compared emergent and benthic macroinvertebrate assemblages from 20 headwater streams in the central Oregon Coast Range that varied by harvest condition and flow duration. Through comparison of the...
The anthropogenic introduction of nutrients to water bodies has been shown to alter the structure and function of natural aquatic ecosystems, yet national EPA lake and reservoir nutrient criteria remain too broad for effective regional water quality management. This study uses a reference site approach to propose numeric nutrient criteria...
The following three essays explore the use of the directional output distance function (Chambers et al., 1996), an economic model originally developed to measure efficiency and productivity for multi-input and multi-output production processes, to assess performance for multi-attributed environmental processes.
The first essay illustrates the use of the directional output...
We quantified the patterns in macroinvertebrate assemblages and their
associated environmental gradients from 457 least-disturbed wadeable
stream sites across the 48 contiguous United States sampled as part
of US EPA’s National Wadeable Stream Assessment. The majority of the
variation in assemblage composition at the finest taxonomic resolution
was related to...
Most studies dealing with the use of ecological indicators and other applied ecological research rely on some definition or concept of what constitutes least-, intermediate- and most-disturbed condition. Currently, most rigorous methodologies designed to define those conditions are suited to large spatial extents (nations, ecoregions) and many sites (hundreds to...
Numerous studies have linked individual nutrient loadings from the Mississippi and Atchafalaya Rivers to
the growth of the hypoxic, or oxygen depleted, zone in the northern Gulf of Mexico. However, in the
discussion of policy to remediate Gulf hypoxia, it is beneficial for stakeholders and policymakers to obtain
a single...
Assessing the ecological impacts of anthropogenic pressures is a key task in environmental management. Multimetric indices (MMIs), based on aquatic assemblage responses to anthropogenic pressures, have been used increasingly throughout the world. The MMI approach is a low-cost, rapid field method that produces an aquatic condition index that responds precisely...
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Herlihy et al. (2008) showed
that objective, quantitative methods – rather than subjective hand-
picked
Red alder (Alnus rubra), a nitrogen(N)-fixing deciduous broadleaf tree, can strongly influence N
concentrations in western Oregon and Washington. We compiled a database of stream N and GIS-derived landscape
characteristics in order to examine geographic variation in N across the Oregon Coast Range. Basal area
of alder, expressed as a...
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88 2000-2006 Compton et al. (2003); Ebersole et al. (2009)
EMAP projects Herlihy and Sifneos (2008
This work furthers the understanding of processes occurring in catchments that affect stream nitrate concentrations using two different approaches: a temporally intensive case study of three headwater catchments with varying land use (through storm event monitoring) and a spatially intensive study on the regional scale (through statistical modeling) of 1st-4th...