DISSERTATION RESEARCH: Predicting community response to N-enrichment using plant traits

人类活动，包括化石燃料的使用，增加了全球可用氮的数量。这种增加的氮可用性可以改变植物群落，并导致植物物种多样性下降。理解氮富集的影响的一个挑战是，社区表现出广泛的反应。为什么有些社区反应强烈，而另一些社区则没有，我们能否确定表明哪些社区最脆弱的因素？该项目将测试与氮素使用相关的植物性状（例如，比叶面积、叶碳氮比和叶氮磷比）可以帮助理解氮富集的生态响应。它将解决两个问题：1）氮富集是否导致向具有某些性状的物种转移，以及2）在富集之前，由具有某些性状的物种和/或具有较窄范围的性状的物种组成的群落中是否存在更强的多样性下降？该研究包括在美国10个栖息地进行的35个氮肥试验中的260个物种，将量化叶片性状之间的关系和氮富集导致的物种组成变化。这项研究将是第一个使用大规模的，多系统的植物性状变化来预测氮富集的影响。该项目将支持一名博士生的研究。数据将公开提供，供进一步研究和教育机会，并将创建一个互动网站，帮助高中学生直观地了解不同社区的氮富集威胁。

Human activities, including the use of fossil fuels, have increased the amount of available nitrogen globally. This increased nitrogen availability can alter plant communities and lead to decreased plant species diversity. One challenge to understanding the impacts of nitrogen enrichment is that communities exhibit a wide range of responses. Why do some communities respond strongly while others do not, and can we identify factors that indicate which communities are most vulnerable? This project will test whether plant traits associated with nitrogen use (e.g., specific leaf area, leaf carbon to nitrogen ratios, and leaf nitrogen to phosphorus ratios) can help to understand ecological responses to nitrogen enrichment. It will address two questions: 1) does nitrogen enrichment cause a shift toward species with certain traits, and 2) are there stronger diversity declines in communities composed of species with certain traits and/or with a narrower range of traits prior to enrichment? Encompassing 260 species in 35 nitrogen fertilization experiments in 10 habitats across the United States, the research will quantify relationships among leaf traits and changes in species composition due to nitrogen enrichment. This research will be the first to use large-scale, multisystem variation in plant traits to predict the impacts of nitrogen enrichment. This project will support the research of a doctoral student. Data will be made publicly available for further studies and educational opportunities, and an interactive website will be created to help high school students visualize nitrogen enrichment threats in different communities.