Ecological Modeling in Risk Assessment - Chapter 5 docx

... belongs. Age- and stage-structured models have been important tools in natural * RAMAS is a registered trademark of Applied Biomathematics. 157 4CH 05. fm Page 55 Tuesday, November 26, 2002 4 :55 PM © ... it. Relevance — HIGH — Possible endpoints include expected population size (age- or stage-specific), risk of decline, risk of extinction, and expected crossing time (the time at whi...

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... capabilities include forecasting vegetative structure, assessing wildlife habitat, analyzing fire hazard, determining forest health risk, and monitoring ecological processes. Using a parallel processing ... developing silvicultural prescriptions, evaluating management scenar - ios, updating inventory information, and providing input to forest planning models (USDA 1999 and reference...

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... Number 1 -5 667 0 -5 7 4-6 Library of Congress Card Number 2001038278 Printed in the United States of America 1 2 3 4 5 6 7 8 9 0 Printed on acid-free paper Library of Congress Cataloging -in- Publication ... applied in this way. So far, we have discussed the use of ecological modeling in evaluating the ecological signifi- cance of risks to individual organisms. In additi...

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... combines the information in all these map layers into a map of habitat suitability expressed as a user-defined habitat suitability function. 157 4CH07.fm Page 87 Tuesday, November 26, 2002 5: 05 ... extinction), a generic metapopulation model (Possingham and Davies 19 95) • Meta-X, an occupancy status model currently being developed (UFZ and OFFIS 2000) In this chapter, we also in...

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... generally interacts with other species in feeding relationships, either feeding on other species, being fed upon by other species, or both. Second, a receptor of concern in an ecological risk assessment ... Volterra 1926; Watt 1 959 ; Holling 1 959 , 1966; Ivlev 1961; Hassell and Varley 1969; Gallopin 1971; DeAngelis et al. 19 75; Arditi and Ginzburg 1989) • Population-dynamic fo...

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... model are relevant to ecological risk assessment. The examination of direct and indirect effects of stressors (e.g., entrain - ment) is of high interest in ecological risk assessment. Although ... LEEM was initiated by the International Joint Commission to aid in anticipating the effects of declining nutrient loading, invasion of zebra mussels, loading of toxic organic con...

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... modeling (Nestler 2001, pers. comm.). The modeling strategy inherent in CEL HYBRID has subtle problems in maintaining conser- vation when any sources or sinks are present and a problem with inflation ... the biology. An individual-based population model is a specific example of the broader CEL HYBRID approach to modeling. What individual-based modeling does for population modelin...

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... discrete or continuous- time) and deterministic life-history matrix models are most appropriate for screening-level ecolog - ical risk assessments (Table 13.1). Some simple food-web models, founded ... 2 Endpoints: Expected future abundance, risk of decline in abundance, risk of extinction, time to extinction, time to decline, toxicant concentration in the environment, toxican...

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... met by integrating existing models but, in rare cases, the management question may require a completely new modeling approach. INVESTMENT TRADE-OFFS Investments in enhancing the use of ecological ... limiting factor. The third trade-off is between integrating existing models and creating new models (Fig- ure 14.1). Integrating existing models results in models with enhanced capa...

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... assessing the significance of estimated risks initially expressed in terms of individual-level end - points. In this mode, ecological models aid in translating risks for individual-level endpoints ... cost-effective approach for addressing many risk assessment issues (Ferson et al. 1996; Barnthouse 1998). Indeed, incorporation of simple, scalar population modeling into sc...

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