The Experts below are selected from a list of 10470 Experts worldwide ranked by ideXlab platform
Stephen P Wente - One of the best experts on this subject based on the ideXlab platform.
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proximity based measure of land use impacts to aquatic Ecosystem Integrity
Environmental Toxicology and Chemistry, 2000Co-Authors: Stephen P WenteAbstract:A proximity-based measure of land-use impacts to aquatic Ecosystem Integrity based on both the relative abundance and spatial distribution of land uses within a watershed is developed and evaluated. This hydrologic proximity measure assumes that the impact of the land use at a specific position in the watershed upstream from a sample site is related to the relative volume of water that would be expected to flow through that position during a storm event. In order to evaluate the utility of this measure, the fit of several models based on land use and habitat assessment measures to biological Integrity data is compared to the fit of a similar model based on hydrologic proximity measures. This hydrologic proximity model explained more of the variability in observed Hilsenhoff biotic index scores (R 2 = 0.92) than land use impacts estimated as the watershed surface area occupied by each land use (R 2 = 0.83), U.S. Environmental Protection Agency habitat assessment methods (R 2 = 0.68), or Ohio Environmental Protection Agency habitat assessment methods (R 2 = 0.68). Additionally, an algorithm based on the hydrologic proximity measure is presented for optimizing land use conversion projects to enhance biological Integrity.
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Proximity‐based measure of land use impacts to aquatic Ecosystem Integrity
Environmental Toxicology and Chemistry, 2000Co-Authors: Stephen P WenteAbstract:A proximity-based measure of land-use impacts to aquatic Ecosystem Integrity based on both the relative abundance and spatial distribution of land uses within a watershed is developed and evaluated. This hydrologic proximity measure assumes that the impact of the land use at a specific position in the watershed upstream from a sample site is related to the relative volume of water that would be expected to flow through that position during a storm event. In order to evaluate the utility of this measure, the fit of several models based on land use and habitat assessment measures to biological Integrity data is compared to the fit of a similar model based on hydrologic proximity measures. This hydrologic proximity model explained more of the variability in observed Hilsenhoff biotic index scores (R 2 = 0.92) than land use impacts estimated as the watershed surface area occupied by each land use (R 2 = 0.83), U.S. Environmental Protection Agency habitat assessment methods (R 2 = 0.68), or Ohio Environmental Protection Agency habitat assessment methods (R 2 = 0.68). Additionally, an algorithm based on the hydrologic proximity measure is presented for optimizing land use conversion projects to enhance biological Integrity.
James J. Kay - One of the best experts on this subject based on the ideXlab platform.
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ecological Integrity and the management of Ecosystems
1993Co-Authors: Stephen Woodley, James J. Kay, George FrancisAbstract:SETTING THE STAGE The Notion of Natural and Cultural Integrity, Henry A. Reiger Considerations of Scale and Hierarchy, Anthony W. King Applying Notions of Ecological Integrity, Robert Steedman and Wolfgang Haider Choosing Indicators of Ecosystem Integrity: Wetlands as a Model System, Paul A. Keddy, Harold T. Lee and Irene C. Wisheu APPLYING THE CONCEPTS Measuring Biological Integrity: Lessons from Streams, James R. Karr Monitoring for Ecosystem Integrity, R.E. Munn National and Regional Scale Measures of Canada's Ecosystem Health, I.B. Marshall, H. Hirvonen and E. Wiken National Environmental Monitoring: A Case Study of the Atlantic Maritime Region, N.L. Shackell and B. Freedman Monitoring and Measuring Ecosystem Integrity in Canadian National Parks, Stephen Woodley An Approach to the Development of Biological Sediment Guidelines, Trevor B. Reynoldson and Michael A. Zarull On the Nature of Ecological Integrity: Some Closing Comments, James J. Kay Index
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Thermodynamics and Measures of Ecological Integrity
Ecological Indicators, 1992Co-Authors: James J. Kay, Eric D. SchneiderAbstract:Over the past decade, the authors have studied the organization of Ecosystems using complex systems theory, and in particular non-equilibrium thermodynamics. This study has led to a set of hypotheses concerning the organizational development of Ecosystems, a thermodynamic framework for discussing Ecosystem Integrity, and a set of measures that reflect Ecosystem organization and aid in the assessment of the impact of environmental change. These are presented herein.
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A nonequilibrium thermodynamic framework for discussing Ecosystem Integrity
Environmental Management, 1991Co-Authors: James J. KayAbstract:During the last 20 years our understanding of the development of complex systems has changed significantly. Two major advancements are catastrophe theory and nonequilibrium thermodynamics with its associated theory of self-organization. These theories indicate that complex system development is nonlinear, discontinuous (catastrophes), not predictable (bifurcations), and multivalued (multiple developmental pathways). Ecosystem development should be expected to exhibit these characteristics.
E.m. Maloney - One of the best experts on this subject based on the ideXlab platform.
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How do we take the pulse of an aquatic Ecosystem? Current and historical approaches to measuring Ecosystem Integrity
Environmental toxicology and chemistry, 2019Co-Authors: E.m. MaloneyAbstract:Global environmental monitoring has indicated that the structure and function of some aquatic Ecosystems has been significantly altered by human activities. There are many potential causes for these changes; however, one major concern is the increasing release of anthropogenic contaminants into aquatic environments. Although toxicological responses of individual organisms are typically well characterized, few studies have focused on characterizing toxicity at the Ecosystem level. In fact, because of their scale and complexity, changes in Ecosystem Integrity are rarely considered in assessments of risks to Ecosystems. This work attempts to move the conversation forward by defining Integrity of Ecosystems, reviewing current and historical approaches to measuring Ecosystem Integrity status (e.g., structural and functional measurements), and highlighting methods that could significantly contribute to the field of Ecosystem toxicology (e.g., keystone species, environmental energetics, ecotoxicological modeling, and adverse outcome pathways [AOPs]). Through a critical analysis of current and historical methodologies, the present study offers a comprehensive, conceptual framework for the assessment of risks of contaminant exposure for whole Ecosystems and proposes steps to facilitate better diagnoses of the Integrity of aquatic systems. Environ Toxicol Chem 2019;38:289-301. © 2018 SETAC.
Alexander B. W. James - One of the best experts on this subject based on the ideXlab platform.
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Is structure or function a better measure of the effects of water abstraction on Ecosystem Integrity
Freshwater Biology, 2009Co-Authors: Russell G. Death, Zoë S. Dewson, Alexander B. W. JamesAbstract:Summary 1. Assessments of flow abstractions in streams often focus on changes to biological communities and in-stream physical characteristics, with little consideration for changes in Ecosystem functioning. It is unclear whether functional indicators of Ecosystem health may be useful for assessing the impacts of reduced discharge on small streams. 2. We used weirs and diversions to reduce stream discharge by over 89% in three small New Zealand streams (11–84 L s−1), ranging in water quality from pristine to moderately impaired. 3. We used both structural (benthic invertebrates) and functional (drifting invertebrates, leaf breakdown, coarse particulate organic matter (CPOM) retention and primary productivity) measures of Ecosystem Integrity to compare responses to water abstraction in before-after, control-impact designed experiments during summer 2005. 4. At the pristine site, the density of invertebrates, taxon richness, Macroinvertebrate Community Index (MCI), Quantitative MCI, percentage of Ephemeroptera, Plecoptera and Trichoptera individuals and percentage of filter-feeders decreased in response to reduced flows. Only taxon richness decreased at the mildly impaired stream, and reduced discharge had no effect on the invertebrate community at the stream with the lowest water quality. 5. We found that reduced discharge had little influence on the breakdown rate of willow leaves in mesh bags over 1 month. Primary productivity was also relatively insensitive to water abstraction. However, CPOM retention increased with decreased flows. Drift propensity of invertebrates increased at two sites but only within the first few days after flow reduction. 6. Structural measures of Ecosystem Integrity suggested that the impacts of water abstraction differed among streams of varying water quality, probably because of differences in the sensitivity of invertebrate assemblages in the three streams. In contrast, the three functional measures tested were generally less sensitive to water abstraction impacts, although understanding how stream Ecosystems respond to water abstraction clearly requires that both are considered.
Eric D. Schneider - One of the best experts on this subject based on the ideXlab platform.
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Thermodynamics and Measures of Ecological Integrity
Ecological Indicators, 1992Co-Authors: James J. Kay, Eric D. SchneiderAbstract:Over the past decade, the authors have studied the organization of Ecosystems using complex systems theory, and in particular non-equilibrium thermodynamics. This study has led to a set of hypotheses concerning the organizational development of Ecosystems, a thermodynamic framework for discussing Ecosystem Integrity, and a set of measures that reflect Ecosystem organization and aid in the assessment of the impact of environmental change. These are presented herein.
