Snodgrass Joel W, Casey Ryan E, Joseph Debra, Simon Judith A
Department of Biological Sciences, Towson University, 8000 York Road, Towson, MD 21252, USA.
Environ Pollut. 2008 Jul;154(2):291-7. doi: 10.1016/j.envpol.2007.10.003. Epub 2007 Nov 19.
Stormwater ponds have become common features of modern development and often represent significant amounts of open space in urbanized areas. Although stormwater ponds may provide habitat for wildlife, factors responsible for producing variation in wildlife use of ponds have received limited attention. To investigate the role of variation in species tolerances of pollutants in structuring pond-breeding amphibian assemblages, we exposed species tolerant (Bufo americanus) and not tolerant (Rana sylvatica) of urbanization to pond sediments in laboratory microcosms. Pond microcosms had elevated sediment metal levels and chloride water concentrations. Among R. sylvatica embryos, exposure to pond sediments resulted in 100% mortality. In contrast, B. americanus embryos and larvae experienced only sublethal effects (i.e., reduced size at metamorphosis) due to pond sediment exposure. Our results suggest variation in pollutant tolerance among early developmental stages of amphibians may act in concert with terrestrial habitat availability to structure amphibian assemblages associated with stormwater ponds.
雨水塘已成为现代开发中常见的特征，并且在城市化地区往往代表着大量的开放空间。尽管雨水塘可能为野生动物提供栖息地，但导致池塘野生动物利用情况产生差异的因素却很少受到关注。为了研究污染物耐受性差异在构建池塘繁殖两栖动物群落中的作用，我们在实验室微观环境中，将对城市化耐受性强的物种（美洲蟾蜍）和耐受性弱的物种（林蛙）暴露于池塘沉积物中。池塘微观环境中的沉积物金属含量和氯化物水浓度有所升高。在林蛙胚胎中，暴露于池塘沉积物导致100%死亡。相比之下，美洲蟾蜍胚胎和幼体由于暴露于池塘沉积物中，仅经历了亚致死效应（即变态时体型减小）。我们的结果表明，两栖动物早期发育阶段对污染物耐受性的差异可能与陆地栖息地可用性共同作用，从而构建与雨水塘相关的两栖动物群落。
