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Sensitivity to Change in Arid Land Ecosystems (SCALE)

干旱地区生态系统变化的敏感性 (SCALE)

基本信息

批准号：
9814510
负责人：
James Ehleringer
金额：
$ 90万
依托单位：
University of Utah
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
1998
资助国家：
美国
起止时间：
1998-08-15 至 2002-07-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=9814510&HistoricalAwards=false
关键词：
Sensitivity Change Arid Land Ecosystems

项目摘要

Arid-land ecosystems are among the most sensitive to changes, whether these changes are associated with human land-use activities or shifting climate conditions. These ecosystems experience high variability in precipitation from year to year, with El Nino and La Nina events representing two extremes of the range of moisture input. Most ecosystem processes in arid lands are constrained to brief pulses of moisture. Because of the constraints that the availability of water imposes on arid-land-ecosystem processes, changes in water availability are likely to play a much more prominent role in the functioning of arid-land ecosystems in the near future than are other global change factors. The SCALE project is directed at understanding how both short-term precipitation pulses and longer-term season-to-season and year-to-year variability of precipitation affect ecosystem structure and function. The researchers will examine changes in ecosystem function with respect to carbon, water, nitrogen, and trace-gas fluxes. The core idea of this project is that climate change acts on arid-land ecosystems through changes in the magnitudes and distributions of moisture pulses. The researchers have established that there are species differences in use of soil moisture, implying possible long-term instability in current species composition with a shift in precipitation patterns. Though a series of field experiments, field manipulations, and modeling, the researchers will examine the impacts of climate change on arid-land ecosystems on the Colorado Plateau.

干旱区生态系统对变化最为敏感，无论这些变化是否与人类土地利用活动或变化的气候条件有关。这些生态系统每年的降水量变化很大，厄尔尼诺和拉尼娜事件代表了水分输入范围的两个极端。干旱地区的大多数生态系统过程受限于短暂的水分脉动。由于水的可得性对干旱地生态系统过程的限制，在不久的将来，水的可得性的变化很可能在干旱地生态系统的功能中发挥比其他全球变化因素更为突出的作用。SCALE项目旨在了解短期降水脉冲和较长期降水季节和年变化对生态系统结构和功能的影响。研究人员将研究生态系统在碳、水、氮和微量气体通量方面的变化。该项目的核心思想是气候变化通过湿度脉冲的大小和分布的变化对干旱土地生态系统起作用。研究人员已经确定，物种在利用土壤水分方面存在差异，这意味着随着降水模式的变化，当前物种组成可能存在长期的不稳定性。通过一系列的野外实验、野外操作和建模，研究人员将研究气候变化对科罗拉多高原干旱土地生态系统的影响。