B. R. Hossack
R.A. Knapp
P.S. Corn
S. A. Diamond
P.C. Trenham
D.B. Fagre
M. J. Adams
2005
<p>An increase in ultraviolet-B (UV-B) radiation has been posited to be a potential factor in the decline of some amphibian population. This hypothesis has received support from laboratory and field experiments showing that current levels of UV-B can cause embryo mortality in some species, but little research has addressed whether UV-B is influencing the distribution of amphibian populations. We compared patterns of amphibian presence to site-specific estimates of UV-B dose at 683 ponds and lakes in Glacier, Olympic, and Sequoia–Kings Canyon National Parks. All three parks are located in western North America, a region with a concentration of documented amphibian declines. Site-specific daily UV-B dose was estimated using modeled and field-collected data to incorporate the effects of elevation, landscape, and water-column dissolved organic carbon. Of the eight species we examined (<i>Ambystoma gracile, Ambystoma macrodactylum, Bufo boreas, Pseudacris regilla, Rana cascadae, Rana leuteiventris, Rana muscosa, Taricha granulosa</i>), two species (<i>T. granulosa and A. macrodactylum</i>) had quadratic relationships with UV-B that could have resulted from negative UV-B effects. Both species were most likely to occur at moderate UV-B levels. <i>Ambystoma macrodactylum</i> showed this pattern only in Glacier National Park. Occurrence of <i>A. macrodactylum</i> increased as UV-B increased in Olympic National Park despite UV-B levels similar to those recorded in Glacier. We also found marginal support for a negative association with UV-B for <i>P. regilla</i> in one of the two parks where it occurred. We did not find evidence of a negative UV-B effect for any other species. Much more work is still needed to determine whether UV-B, either alone or in concert with other factors, is causing widespread population losses in amphibians.</p>
application/pdf
10.1007/s10021-003-0033-3
en
Springer
Distribution patterns of lentic-breeding amphibians in relation to ultraviolet radiation exposure in western North America
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