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，政府法规减少了酸雨的水平，并创造了一个机会来评估这些森林从过去的破坏中恢复的能力。评估酸沉降变化的影响需要长期测量和实验，以便发现趋势并更好地了解森林在变化条件下的功能。这样的长期记录和实验极为罕见。这个项目的重点是一个独特的，长期的数据集和操作实验在弗诺实验森林（FEF）在西弗吉尼亚州。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连续进行。它还将继续进行两个互补的实验操作：1989年开始的整个流域酸化实验和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大大提高我们对空气污染变化与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，改进森林管理实践。该项目的数据将与多元素限制（MEL）模型和补充测量一起使用，以检验关于酸和氮沉积对森林流域影响的四个问题：(1)对硝酸盐（水污染的一个来源）的生物需求减少是否导致了硝酸盐损失的增加？(2)幼林氮素添加后的更大硝酸盐损失是由于硝酸盐产量增加以外的原因吗？(3)长期加氮和酸化是否会降低幼林的碳储量？(4)氮有效性的提高是否降低了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来研究更多的氮供应是否会导致森林更容易受到严重风暴事件的破坏。该项目将延续过去5年培训了20名学生的实习项目和创意写作课程，旨在通过挑战他们了解（和反思）在FEF的长期研究，激励新一代非小说作家。这个写作课程在过去三年里培训了18名学生，是全国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.