Forest-Atmosphere Fluxes in a Subalpine Ecosystem

亚高山森林生态系统是美国西部城市和郊区中心的关键自然资源。这个生态系统在山区占主导地位，提供水、娱乐和木材等商品和服务。它也是大陆大气二氧化碳汇的重要组成部分。近几十年来，由于区域气候变暖、山松甲虫等昆虫流行病的爆发以及附近人口中心的臭氧和氮氧化物等污染物的暴露，这些森林的压力越来越大。这项研究将继续一项为期十年的计划，监测丹佛市走廊以西的亚高山森林，以评估生长、水预算和持续碳吸收的潜力。很明显，随着时间的推移，这片森林很容易从大气中吸收更少的二氧化碳，而且由于变暖和相关的积雪减少，它的生长速度正在放缓。此外，有迹象表明，山松甲虫已开始暴发。因此，森林正处于表现出对环境变化的重要和主要反应的尖端。这项研究包括测量未来五年科罗拉多州尼德兰附近的森林与大气之间的二氧化碳、水和能量交换，以评估其对这些压力的反应。除了开展研究外，这项提案还将对科学界产生更广泛的影响，因为它将继续作为研究生和博士后个人项目的培训设施，继续在科罗拉多大学山区研究站为来自世界各地的研究生举办暑期课程，并继续作为全球碳预算建模的主要数据来源。

The subalpine forest ecosystem is a critical natural resource to urban and suburban centers in the western United States. This ecosystem is dominant in mountain regions and provides goods and services such as water, recreation and timber. It is also a critical component of the continental sink for atmospheric carbon dioxide. These forests have become increasingly stressed in recent decades due to regional climate warming, outbreaks of insect epidemics such as the mountain pine beetle, and exposure to pollutants such as ozone and nitrogen oxides from nearby population centers. The research proposed would continue a ten year program of monitoring a subalpine forest west of the Denver metropolitan corridor to assess growth, water budgets, and the potential for continued carbon absorption. It has become apparent that this forest is susceptible to absorbing less carbon dioxide from the atmosphere over time and that it is growing at slower rates due to warming and associated reduced snowpacks. Furthermore, there have been signs of incipient outbreak of the mountain pine beetle. Thus, the forest is at the cusp of exhibiting important and major responses to environmental change. This research includes measurements of carbon dioxide, water and energy exchange between the forest located near Nederland, Colorado, and the atmosphere over the next five years to assess its response to these stresses. In addition to conducting research, this proposal will have broader impacts to the scientific community through its continuation as a training facility for individual graduate student and post-doctoral student projects, continuation of a summer course for graduate students from across the world at the University of Colorado Mountain Research Station, and continuation as a primary data resource for global carbon budget modeling.