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Extramural Research

Grantee Research Project Results

Grantee Research Project Results

Assessing the Population-Level Effect of UV-B Induced Mortality in Amphibians

EPA Grant Number: U915824
Title: Assessing the Population-Level Effect of UV-B Induced Mortality in Amphibians
Investigators: Vonesh, James R.
Institution: University of Florida
EPA Project Officer: Jones, Brandon
Project Period: August 1, 2000 through August 1, 2003
Project Amount: $83,554
RFA: STAR Graduate Fellowships (2000)
Research Category: Academic Fellowships , Ecological Indicators/Assessment/Restoration , Fellowship - Ecology



The objective of this research project is to develop a heuristic model to explore the population-level consequences of egg-stage mortality in amphibians when there is larval-stage density-dependence.


The focus is on four species known to be vulnerable to UV-B: Bufo bufo, Bufo boreas, Rana cascadae, and Ambystoma macrodactylum. A stage-structured demographic model will be developed that explicitly incorporates larval-stage density-dependence to examine the sensitivity of population size to changes in a number of life history parameters, including egg survival.

Expected Results:

The effect of embryonic mortality on amphibian populations may depend upon the functional form of larval density dependence, and density dependence can moderate the population-level consequences of mortality early in life history for some species. In addition, while many recent studies have focused on species-specific differences in UV sensitivity, variation among species in their population-level responses to egg-stage mortality could also be explained simply by differences in the density dependence experienced in their life histories.

Supplemental Keywords:

ambystoma, amphibian population declines, Bufo, density dependence, Rana, stage structure, population model, UV sensitivity hypothesis., RFA, Scientific Discipline, Air, Ecosystem Protection/Environmental Exposure & Risk, exploratory research environmental biology, Ecosystem/Assessment/Indicators, amphibians, climate change, Ecological Effects - Environmental Exposure & Risk, Ecological Effects - Human Health, Environmental Monitoring, Biology, Ecological Indicators, ecological effects, molecular genetics, UV light, cell function, ecological exposure, UV effects, UV-A light, amphibian malformations, excision-repair proteins, immune function, population decline, membrane lipid assays, UV induced mortality, photolyase expression, mortality, UV-B, DNA repair, amphibian bioindicator, climate variability

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The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.

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