DISSERTATION RESEARCH: Amphibians and Mineralized Nitrogen: Hidden Jeopardy?

论文研究：两栖动物和矿化氮：隐藏的危险？

• 批准号: 0407918
• 负责人: Mark Ritchie
• 金额: $ 1.2万
• 依托单位: Syracuse University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-06-01 至 2005-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0407918&HistoricalAwards=false
• 关键词: DISSERTATION; RESEARCH; Amphibians; Mineralized; Nitrogen

Over the past 30 years researchers have become aware of long-term declines in amphibian populations, often starting earlier in this century. Over this same time period, humans have dramatically increased the amount of mineralized nitrogen (N) across the planet. In the Midwest and other areas of similar latitude, early breeding amphibians enter breeding ponds in spring often before ice has completely melted. At this time snowmelt and early rains flush mineral N into surface waters, but there is very little biological uptake. Hence, amphibian embryos and young larvae are exposed to elevated concentrations of N. Preliminary evidence suggests that amphibian embryos and larvae are susceptible to mineral N at concentrations found in the environment, concentrations well below those considered safe for human consumption. In this study I will address the following research questions: 1) does exposure to elevated concentrations of mineral N as embryos and larvae in the laboratory decrease hatching and survival, and increase the time to metamorphosis and deformities in the wood frog and eastern tiger salamander, and 2) do experimentally increased concentrations of mineral N in the field decrease egg hatching, larval survival and development, and increase the frequency of deformities when amphibians are protected from predation. I expect to demonstrate that nitrogen can detrimentally affect amphibian embryos and larvae under realistic conditions and at realistic concentrations. I also expect that this research will show that exposure to mineralized nitrogen as embryos can have very large negative implications for the amphibians once they develop into larvae. My results will potentially provide major insights into the effects of mineral N on amphibian populations and freshwater ecosystems; thus, revealing a previously unrecognized factor in the declines of some amphibian populations.

在过去的30年里，研究人员已经意识到两栖动物种群的长期下降，通常从本世纪开始。 在同一时期，人类大大增加了地球上矿化氮（N）的数量。 在中西部和其他类似纬度的地区，早期繁殖的两栖动物在春天进入繁殖池，通常在冰完全融化之前。 在这个时候，融雪和早期的降雨将矿物质氮冲入地表沃茨，但生物吸收很少。 因此，两栖动物胚胎和幼仔暴露于高浓度的N。 初步证据表明，两栖动物胚胎和幼虫对环境中发现的浓度的矿物质氮很敏感，浓度远低于人类食用的安全浓度。 在这项研究中，我将解决以下研究问题：1）在实验室中暴露于高浓度的矿物质N作为胚胎和幼虫是否会减少孵化和存活，并增加林蛙和东部虎蝾螈的变态和畸形时间，以及2）在野外实验增加矿物质N浓度是否会减少卵孵化，幼虫存活和发育，当两栖动物被保护免受捕食时，畸形的频率会增加。 我希望证明，在现实的条件下，在现实的浓度下，氮可以对两栖动物的胚胎和幼虫产生有害的影响。 我还希望这项研究将表明，暴露于矿化氮作为胚胎可以有非常大的负面影响，两栖动物一旦他们发展成幼虫。 我的研究结果可能会提供重要的见解矿物N对两栖动物种群和淡水生态系统的影响，从而揭示了一些两栖动物种群下降的一个以前未被认识的因素。