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The relationship between riparian areas and biological diversity. A comparison of streams in eastern Colorado and southwestern Virginia. By Ann Widmer 12-9-03. EPA’s need for monitoring…. EPA Administrator William Reilly (1989)—
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The relationship between riparian areas and biological diversity A comparison of streams in eastern Colorado and southwestern Virginia By Ann Widmer 12-9-03
EPA’s need for monitoring… EPA Administrator William Reilly (1989)— “Good News– Based on my years in the environmental movement, I think the Agency does an exemplary job of protecting the nation’s public health and quality of the environment. Bad news– I can’t prove it.” http://www.epa.gov/emap.html
(environmental monitoring and assessment program) Key components: • statistical design • wide-scale application across the country • use of biological indicators
What is an indicator? • An instrument for monitoring the operation or condition of a physical system • Webster’s II New Riverside University Dictionary
EMAP Measurements • Fish assemblage • Benthic macroinvertebrates • Periphyton • Water quality • Habitat parameters • Substrates • Embeddedness • Riparian vegetation Plecoptera (stonefly) Periphyton on river rocks
Do indicators work?(Are they a good measure of ecological health?)
2 healthy aquatic systems Completely different stream character.
My project • EMAP sampling in Colorado • Concerns • Qualitative data • Comparison of trends to those in southwest Virginia • Development of indicies • Intensively studied area
Trends in southwest Virginia 1. As riparian vegetation is decreased, fish and mussel species diversity is decreased Diamond, J.M., and V.B. Serveiss. 2001. Identifying sources of stress to native aquatic fauna using a watershed ecological risk assessment framework. Environmental Science Technology 35: 4711-4718.
Trends in southwest Virginia 2. As riparian vegetation is decreased, benthic macroinvertebrate density is decreased. Effect more pronounced very locally (within 200 meters) Sponseller, R.A., E.F. Benfield, and H.M. Valett. 2001. Relationships between land use, spatial scale, and stream macroinvertebrate communities. Freshwater Biology 46: 1409-1424.
Colorado streams(variation with elevation) Above timberline
Colorado streams(variation with elevation) Forested mountain
Colorado streams(variation with elevation) Urban– Front Range
Additional considerations… • Scale • Virginia studies were in a small watershed • Colorado study encompasses half a state– compare within similar conditions • Sedimentation • Land use and fish stocking • Water quality
Comparison of similar streams • Bear Creek, CO • Boulder Creek, CO • Clear Creek, CO • Found the highest fish species diversity and density in the Bear Creek, the one with the most riparian vegetation
Recommendations to the EPA • Indicators should not be used to compare health of dissimilar streams • Different states – big difference in riparian size • Different elevation • Different stream order • Indicators most useful when comparing the same site over time– environmental monitoring