DISSERTATION RESEARCH: Climate change and regime shifts

论文研究：气候变化和政权更迭

• 批准号: 1210531
• 负责人: David Post
• 金额: $ 1.5万
• 依托单位: Yale University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-05-15 至 2014-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1210531&HistoricalAwards=false
• 关键词: DISSERTATION; RESEARCH; Climate; change; regime

Understanding how climate change alters interactions among species is one of the big challenges facing ecologists today. The consequences of changes to existing interactions among species are especially important in lake ecosystems where there is the potential for shifts between alternate states. Lakes often can be found in either a clear-water state with little algal growth, or a turbid state in which there are frequent dense algal blooms. Two factors which largely determine whether a lake will be clear or turbid are nutrients and algal consumers. Nutrients, especially nitrogen and phosphorus, increase the growth rate of algae leading to algal blooms and a turbid state. Algal consumers, particularly of the genus Daphna, are very effective grazers of algae, limiting their populations and promoting the clear-water state. The increase in global temperatures is decreasing the length and severity of winters, which increases the abundance of over-wintering Daphnia. This study focuses on understanding how lake nutrient status affects the climate driven differences in over-wintering of Daphnia. Experimental ponds will be used to perform the critical experiment to determine where the tipping point between a turbid and a clear-water state is across the range of lake nutrient concentrations and overwintering Daphnia abundance seen in natural lakes. Determining the conditions that bring about shifts between ecosystem states is an important part of the management of ecosystems under a changing climate. This research will answer fundamental questions about alternate states in lakes and provide a useful tool for lake managers to use for promoting the clear-water state in lakes. Results of this study will be published in a management oriented journal; as well an ecological journal to ensure they reach the audience that can make use of them. This study will determine the densities of Daphnia required to be achieved for a given nutrient level, providing lake managers with targets for their management activities to maintain beautiful clear lakes. Additionally, this project will provide an undergraduate student with training and mentoring in the conduct of scientific research.

了解气候变化如何改变物种之间的相互作用是当今生态学家面临的重大挑战之一。 物种之间现有相互作用的变化的后果在湖泊生态系统中尤为重要，在湖泊生态系统中可能会发生替代状态之间的转变。 湖泊通常可以在藻类生长几乎没有生长的透明水状态下找到，也可以在浑浊的状态下发现频繁的藻类开花。 两个因素在很大程度上决定了湖泊是否会清晰或浑浊的养分和藻类消费者。 养分，尤其是氮和磷，增加了藻类的生长速率，导致藻华和浑浊的状态。 藻类消费者，尤其是达芙娜属的消费者，是藻类的非常有效的放牧者，限制了其人群并促进了清澈的水状态。 全球温度的升高是降低了冬季的长度和严重程度，这增加了过度冬季的丰度。 这项研究重点是了解湖泊养分状况如何影响水坝过多冬季的气候驱动差异。 实验池将用于执行关键实验，以确定浑浊和清水状态之间在湖泊营养浓度范围内以及在天然湖泊中看到的冬季丰富的水磷脂的范围。确定生态系统状态之间发生变化的条件是在不断变化的气候下管理生态系统的重要组成部分。 这项研究将回答有关湖泊中替代状态的基本问题，并为湖泊经理提供有用的工具，用于促进湖泊中的清水状态。 这项研究的结果将发表在以管理为导向期刊上；以及一个生态期刊，以确保他们能够吸引能够利用它们的受众。 这项研究将确定给定养分水平需要达到的水饮料的密度，从而为湖经理提供了其管理活动的目标，以维持美丽的晴朗湖泊。 此外，该项目将为本科生提供科学研究的培训和指导。