Adams Michael J, Schindler Daniel E, Bury Bruce R
USGS Forest and Rangeland Ecosystem Science Center, 3200 SW Jefferson Way, 97331, Corvallis, OR, USA.
Department of Zoology, University of Washington, Box 351800, 98195-1800, Seattle, WA, USA.
Oecologia. 2001 Aug;128(4):519-525. doi: 10.1007/s004420100688. Epub 2001 Aug 1.
Ambient ultraviolet-b (UV-B) radiation (280-320 nm) has increased at north-temperate latitudes in the last two decades. UV-B can be detrimental to amphibians, and amphibians have shown declines in some areas during this same period. We documented the distribution of amphibians and salmonids in 42 remote, subalpine and alpine ponds in Olympic National Park, Washington, United States. We inferred relative exposure of amphibian habitats to UV-B by estimating the transmission of 305- and 320-nm radiation in pond water. We found breeding Ambystoma gracile, A. macrodactylum and Rana cascadae at 33%, 31%, and 45% of the study sites, respectively. Most R. cascadae bred in fishless shallow ponds with relatively low transmission of UV-B. The relationship with UV-B exposure remained marginally significant even after the presence of fish was included in the model. At 50 cm water depth, there was a 55% reduction in incident 305-nm radiation at sites where breeding populations of R. cascadae were detected compared to other sites. We did not detect associations between UV-B transmission and A. gracile or A. macrodactylum. Our field surveys do not provide evidence for decline of R. cascadae in Olympic National Park as has been documented in Northern California, but are consistent with the hypothesis that the spatial distribution of R. cascadae breeding sites is influenced by exposure to UV-B. Substrate or pond depth could also be related to the distribution of R. cascadae in Olympic National Park.
在过去二十年中，北温带地区的环境紫外线B（UV-B，280 - 320纳米）辐射有所增加。UV-B对两栖动物可能有害，在此期间一些地区的两栖动物数量出现了下降。我们记录了美国华盛顿州奥林匹克国家公园42个偏远的亚高山和高山池塘中两栖动物和鲑科鱼类的分布情况。通过估算池塘水中305纳米和320纳米辐射的透过率，我们推断了两栖动物栖息地相对UV-B的暴露情况。我们发现，在分别33%、31%和45%的研究地点发现了细口钝口螈、大趾钝口螈和喀斯喀特林蛙的繁殖活动。大多数喀斯喀特林蛙在无鱼的浅池塘中繁殖，这些池塘的UV-B透过率相对较低。即使在模型中纳入鱼类的存在后，与UV-B暴露的关系仍略显显著。在水深50厘米处，与其他地点相比，检测到喀斯喀特林蛙繁殖种群的地点，入射的305纳米辐射减少了55%。我们未检测到UV-B透过率与细口钝口螈或大趾钝口螈之间的关联。我们的实地调查没有提供证据证明奥林匹克国家公园的喀斯喀特林蛙数量像北加利福尼亚记录的那样下降，但与喀斯喀特林蛙繁殖地点的空间分布受UV-B暴露影响这一假设一致。底物或池塘深度也可能与奥林匹克国家公园喀斯喀特林蛙的分布有关。
