DISSERTATION RESEARCH: Combined Effects of Plant Species Loss and Increased Nitrogen Availability on Ecosystem Processes in Montane Meadow Habitat

论文研究：植物物种丧失和氮素可用性增加对山地草甸生境生态系统过程的综合影响

• 批准号: 0309104
• 负责人: John Harte
• 金额: $ 0.9万
• 依托单位: University of California-Berkeley
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-06-01 至 2006-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0309104&HistoricalAwards=false
• 关键词: DISSERTATION; RESEARCH; Combined; Effects; Plant

Human activities are increasingly stressing the global environment, leading to a warmer climate, increased nitrogen deposition, and the loss of biodiversity. These global changes have the potential to significantly affect local ecosystems. For example, climate warming can have direct effects on ecosystem processes such as plant productivity, carbon sequestration and nitrogen cycling. Warming can also have indirect effects on those processes via its effect on plant species diversity and soil nitrogen availability. My research draws on results from an on-going warming experiment, and completes a triad of climate manipulation, pattern analysis, and plant species/nitrogen manipulations by crossing plant species removal with nitrogen addition treatments in a montane meadow ecosystem. I am removing those plant species with relatively shallow rooting structures, which on the basis of the warming manipulation are the ones most likely to be stressed by future warming. The level of nitrogen addition is motivated by an observed increase in soil nitrogen availability in the warming experiment. By monitoring how the loss of species and the addition of nitrogen affect plant productivity, carbon sequestration and nitrogen cycling, my research will improve our ability to make predictions about how the anthropogenic stress of climate change may affect important ecosystem processes.

人类活动对全球环境的压力越来越大，导致气候变暖，氮沉降增加，生物多样性丧失。这些全球变化有可能对当地生态系统产生重大影响。例如，气候变暖可对植物生产力、碳固存和氮循环等生态系统进程产生直接影响。气候变暖还可以通过影响植物物种多样性和土壤氮素供应对这些过程产生间接影响。我的研究借鉴了正在进行的变暖实验的结果，并通过在山地草甸生态系统中将植物物种去除与氮添加处理相结合，完成了气候操纵、模式分析和植物物种/氮操纵的三位一体。我正在移除那些根结构相对较浅的植物物种，根据变暖的操纵，它们最有可能受到未来变暖的影响。氮添加水平的动机是在变暖实验中观察到的土壤氮的有效性增加。通过监测物种的丧失和氮的添加如何影响植物生产力、碳封存和氮循环，我的研究将提高我们预测人为气候变化压力如何影响重要生态系统过程的能力。