CAA: Linking Ecosystem and Population Ecology: How Does Nitrogen Deposition Influence Plant Demography in Neotropical Savannas?

人类活动，如燃烧化石燃料和使用化肥，使陆地生态系统中的氮量增加了一倍以上。这种增长可能会对生态系统的性质产生深远的影响，但它如何影响植物种群的动态尚不清楚。布鲁纳和他的合作者将进行一项实验测试，测试氮素强化如何影响热带稀树草原植物种群的动态。他们将在试验田中操纵氮素水平，并使用矩阵模型来阐明优势束草(Tristachya Leiostachya)的人口学特征，并观察该物种丰度的变化如何影响生态系统特性，如净氮矿化率。由于热带生态系统对氮沉降的生态反应可能与温带生态系统截然不同，布鲁纳的研究将解决我们对热带植物种群如何调节的一个重大缺口。此外，人们普遍认为，人为氮沉积对整个发展中世界的生态系统构成新的威胁。因此，这项工作将对保护具有重要意义。最后，这项研究将支持少数族裔科学家的学术进步，并加强社区学院和少数族裔服务机构教员教授的课程的生态内容。

Human activities such as the combustion of fossil fuels and the application of chemical fertilizers have more than doubled the quantity of nitrogen in terrestrial ecosystems. This increase can have profound consequences for ecosystem properties, but how it influences the dynamics of plant populations remains unknown. Bruna and his collaborators will conduct an experimental test of how nitrogen enhancement influences the dynamics of plant populations in tropical savannas. They will manipulate nitrogen levels in experimental plots and use matrix models to elucidate the demography of a dominant bunchgrass (Tristachya leiostachya), and to observe how changes in the abundance of this species influence ecosystem properties such rates of net nitrogen mineralization.Because the ecological responses of tropical ecosystems to nitrogen deposition are likely to be dramatically different from those of temperate ones, Bruna's research will address a major gap in our understanding of how tropical plant populations are regulated. Furthermore, anthropogenic nitrogen deposition is widely recognized as an emerging threat to ecosystems throughout the developing world. Thus, this work will have important implications for conservation. Finally, this research will support the academic advancement of minority scientists, as well as enhance the ecological content of courses taught by faculty at community colleges and minority-serving institutions.