LTREB: Linking Long-term Alterations in Atmospheric Chemistry to Changes in Nutrient Dynamics and Sustainable Productivity in Central Appalachian Forests

该项目将继续在Fernow实验森林进行长期测量和实验，以便更好地了解空气污染如何影响阿巴拉契亚中部阔叶林的肥力、生产力和组成。该地点最近的变化表明，持续的酸沉积将耗尽必需的土壤养分，并以降低森林生产力的方式改变可用养分的平衡。对降水、水流、土壤和植被（包括未经处理的和经过实验处理的地点）的持续测量将回答几个重要问题：(1)是否有证据表明酸沉降降低了森林生产力？(2)一些森林能抵抗慢性酸沉降的影响多长时间？(3)为什么该地点的河流化学的长期变化不同于在美国东部其他污染地区观察到的变化？(4)持续的酸沉降是否会改变树种的多样性和组成？长期数据很少，但对于检测环境变化和量化其生态影响是必要的。因此，该项目的结果将大大提高我们对空气污染变化与森林生产力之间联系的理解，为公共政策、生态理论和森林管理实践提供信息。

This project will continue long-term measurements and experiments at the Fernow Experimental Forest in order to better understand how air pollution affects the fertility, productivity, and composition of hardwood forests in central Appalachia. Recent changes at this site suggest that continued acid deposition will deplete essential soil nutrients and alter the balance of available nutrients in ways that reduce forest productivity. Continuing measurements of precipitation, stream water, soils, and vegetation (in both untreated and experimentally manipulated sites) will answer several important questions: (1) Is there evidence that acid deposition has reduced forest productivity ?; (2) How long can some forests resist the effects of chronic acid deposition ?; (3) Why are long-term changes in stream-water chemistry at this site different than changes observed in other polluted regions of the eastern US ?; and (4) Will continued acid deposition alter the diversity and composition of tree species?Long-term data are rare but necessary for detecting environmental change, and for quantifying its ecological impact. Thus, results from this project will significantly improve our understanding of the link between changes in air pollution and forest productivity in ways that can inform public policy, ecological theory, and forest management practices.