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

几十年来，化石燃料的燃烧产生了大量的酸雨，威胁着阿巴拉契亚森林的生产力、肥力、水质和生物多样性。最近，政府法规降低了酸雨水平，并创造了一个评估这些森林从过去的破坏中恢复的能力的机会。评估酸沉积变化的影响需要长期的测量和实验，以便发现趋势并更好地了解森林在变化的条件下如何发挥作用。这样的长期记录和实验是极其罕见的。该项目的重点是在西弗吉尼亚州的费诺实验森林(FEF)进行独特的长期数据集和操纵实验。这项研究将继续进行长期测量，其中一些测量自1951年以来一直在FEF进行。它还将继续进行两个相辅相成的实验操作：1989年开始的全流域酸化实验和1996年开始的长期土壤生产力实验。这些实验产生的独特数据将显著提高我们对空气污染变化和森林健康之间联系的理解，为公共政策提供信息，加强生态理论，并改善森林管理实践。该项目的数据将与多元素限制(MEL)模型和补充测量一起用于研究关于酸和氮沉积对森林流域的影响的四个问题：(1)对硝酸盐(水污染的来源)的生物需求减少是否导致硝酸盐损失增加？(2)幼林增加氮素后，硝酸盐损失是否由于硝酸盐产生率增加以外的其他原因？(3)长期的氮素添加和酸化是否会减少幼林中的碳储存？(4)氮素有效性的增加是否会减少森林草本植物和树木的多样性？此外，超级风暴桑迪在FEF造成的大量破坏创造了一个独特的机会，可以研究更多的氮素供应是否会导致森林更容易受到严重风暴事件的破坏。这个项目将继续一个实习计划，在过去的5年里培训了20名学生，以及一个创造性的写作课程，旨在通过挑战他们学习(和反思)在FEF的长期学习来激励新一代非小说类作家。写作课程在过去3年里培训了18名学生，是国家生态反思网络的一部分。

For decades the burning of fossil fuels created large amounts of acid rain that threatened the productivity, fertility, water quality, and biodiversity of Appalachian forests. More recently, government regulations have reduced the levels of acid rain and created an opportunity to assess the ability of these forests to recover from past damage. Assessing the impact of changes in acid deposition requires long-term measurements and experiments in order to detect trends and better understand how forests function under changing conditions. Such long-term records and experiments are extremely rare. This project focuses on a unique, long-term dataset and manipulative experiments at the Fernow Experimental Forest (FEF) in West Virginia. The research will continue long-term measurements, some of which have been made continuously at FEF since 1951. It will also continue two complementary experimental manipulations: a whole-watershed acidification experiment that began in 1989, and a Long Term Soil Productivity experiment that began in 1996. The unique data resulting from these experiments will significantly improve our understanding of the link between changes in air pollution and forest health in ways that inform public policy, enhance ecological theory, and improve forest management practices.Data from this project will be used along with the Multiple Element Limitation (MEL) model and supplemental measurements to examine four questions about the impacts of acid and nitrogen deposition on forested watersheds: (1) Has a diminished biological demand for nitrate (a source of water pollution) contributed to enhanced nitrate losses?; (2) Are greater nitrate losses following nitrogen additions to a young forest due to something other than increased rates of nitrate production?; (3) Will chronic nitrogen addition and acidification diminish carbon storage in young forests?; and (4) Does enhanced nitrogen availability reduce the diversity of forest herbs and trees? In addition, a significant amount of damage caused by Superstorm Sandy at the FEF created a unique opportunity to examine whether greater nitrogen availability causes forests to be more susceptible to damage by severe storm events. This project will continue an internship program that trained 20 students during the last 5 years and a creative writing course designed to inspire a new generation of non-fiction writers by challenging them to learn about (and reflect on) the long-term studies at the FEF. The writing course trained 18 students in the last 3 years and is part of the National Ecological Reflections Network.