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: Packard, Benjamin H
Project Period: August 1, 2000 through August 1, 2003
Project Amount: $83,554
RFA: STAR Graduate Fellowships (2000) RFA Text |  Recipients Lists
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, cell function, molecular genetics, ecological effects, ecological exposure, UV light, UV effects, UV-A light, amphibian malformations, excision-repair proteins, population decline, immune function, UV induced mortality, membrane lipid assays, photolyase expression, amphibian bioindicator, DNA repair, mortality, UV-B, ultraviolet radiation

Progress and Final Reports:

  • 2001
  • 2002
  • Final