DISSERTATION RESEARCH, Funds for Jonathan E. Hickman: Effects of kudzu (Pueraria montana) on nitrogen oxide fluxes

不同的植物向大气排放不同类型的气体。因此，植物群落组成的变化可能导致生态系统中活性大气化合物产生的巨大变化，其中一些是对流层臭氧形成的关键前体。这项拨款支持一项调查，研究入侵豆科葛的独特生理如何影响美国东部生态系统尺度氮微量气体通量的变化。葛藤的氮氧化物排放将在一个普通的花园环境中进行测量，在一系列湿度条件下，以及在田间成对的入侵和未入侵地点进行测量。还将测量一套氮循环变量，以提供气体通量测量的背景。在葛藤生长的大部分地区，一氧化氮是对流层臭氧形成的限制性前体，即使浓度很低，也对人体健康有害，会导致哮喘，增加对呼吸系统疾病的易感性，以及永久性肺损伤。通过收集一系列温度和湿度处理的氮氧化物排放数据，将与正在进行的野葛异戊二烯通量测量相结合，开发一个生态系统尺度的模型，能够预测野葛如何影响臭氧形成和空气质量。公共宣传将包括对学校和市民团体的演讲，并将对本科生进行科学实践指导。

Different plant species emit different types of gases to the atmosphere. Thus, a shift in plant community composition can result in large changes in an ecosystem's production of reactive atmospheric compounds, some of which are key precursors to tropospheric ozone formation. This grant supports an investigation into how the unique physiology of the invasive legume kudzu (Pueraria montana) contributes to changes in ecosystem-scale fluxes of nitrogen trace gases in the eastern United States. Nitrogen oxide emissions by kudzu will be measured in a common garden setting under a range of moisture conditions, as well as in paired invaded and un-invaded sites in the field. A suite of nitrogen cycling variables will also be measured to provide a context for the gas flux measurements. Throughout much of kudzu's range, nitric oxide is the limiting precursor to tropospheric ozone formation, which is detrimental to human health even at low levels, contributing to asthma, increased susceptibility to respiratory illnesses, and permanent lung damage. Collecting nitrogen oxide emission data across a range of temperatures and moisture treatments will be combined with on-going measurements of kudzu isoprene fluxes to develop an ecosystem-scale model able to predict how kudzu affects ozone formation and air quality. Public outreach will include talks to school and civic groups, and undergraduate students will be mentored in the practice of science.