DISSERTATION RESEARCH: Vegetation Feedbacks to Climate Change: Extending Results from an Ecosystem-Warming Experiment to Landscape Level

论文研究：植被对气候变化的反馈：将生态系统变暖实验的结果扩展到景观水平

• 批准号: 9623258
• 负责人: John Harte
• 金额: $ 0.6万
• 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: 1996
• 资助国家: 美国
• 起止时间: 1996-06-01 至 1998-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9623258&HistoricalAwards=false
• 关键词: DISSERTATION; RESEARCH; Vegetation; Feedbacks; Climate

9623258 Harte Vegetation feedbacks to climate change: extending results from an ecosystem-warming experiment to landscape level. Predictions of global climate change are based on models that largely ignore climate-ecosystem interactions. Yet such interactions may potentially generate large positive or negative feedbacks to the climate. For example, shifts in vegetative cover will alter energy and water exchange with the atmosphere and could be a significant source of feedback To quantify such feedbacks, a detailed and mechanistic understanding of climate-ecosystem interactions on the scale of experimental plots is needed, along with reliable methods for generalizing knowledge obtained from ecosystem experimentation and natural climatic gradient analysis. This project will combine manipulations with elevational transect studies to 1) deepen understanding of mechanisms and contingent factors that shape climate-ecosystem feedbacks, and 2) evaluate and improve the use of transect and manipulation studies for extrapolating results about ecosystem response and feedback to the landscape scale. The focus will be on a shift in dominant vegetation from forbs to shrubs in subalpine meadow habitat in Colorado. This ecosystem response to climate variation has been observed over four years of an experimental simulation of climate warming. Correlations derived from monitoring vegetation and climatic variables along an elevational gradient will be compared with results from 1) the existing and continuing climate manipulation, 2) additional climate manipulations and reciprocal transplants along the gradient, and 3) interannual climatic variation within each data set.

9623258哈特植被对气候变化的反馈：将生态系统变暖实验结果扩展到景观水平。对全球气候变化的预测是基于很大程度上忽略了气候-生态系统相互作用的模型。然而，这种相互作用可能会对气候产生巨大的正反馈或负反馈。例如，植被覆盖的变化将改变与大气的能量和水交换，并可能成为反馈的重要来源，为了量化这些反馈，需要在试验田的尺度上对气候-生态系统相互作用有详细和机制的了解，同时需要可靠的方法来推广从生态系统实验和自然气候梯度分析中获得的知识。该项目将把样带研究与海拔样带研究结合起来，以1)加深对形成气候-生态系统反馈的机制和偶然因素的理解；2)评估和改进样带和样带研究的使用，以推断生态系统响应和反馈到景观尺度的结果。重点将是在科罗拉多州亚高山草甸生境的优势植被从牧草到灌木的转变。这种生态系统对气候变化的响应已经在四年的气候变暖实验模拟中被观察到。通过监测海拔梯度上的植被和气候变量得出的相关性将与以下结果进行比较：1)现有的和持续的气候操纵；2)额外的气候操纵和沿海拔梯度的相互移植；3)每个数据集中的年际气候变化。