DISSERTATION RESEARCH: Scaling Plant Physiology to Ecosystem Ecology: Assessing the Role of the Plant Community in Preventing Nitrogen Losses Following Fire

论文研究：将植物生理学扩展到生态系统生态学：评估植物群落在防止火灾后氮流失中的作用

• 批准号: 1601279
• 负责人: Justin Wright
• 金额: $ 2.04万
• 依托单位: Duke University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-06-01 至 2019-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1601279&HistoricalAwards=false
• 关键词: DISSERTATION; RESEARCH; Scaling; Plant; Physiology

DEB-1601279 Wright, Justin P., Duke University: DISSERTATION RESEARCH: Scaling Plant Physiology to Ecosystem Ecology: Assessing the Role of the Plant Community in Preventing Nitrogen Losses Following Fire.The availability of soil resources, such as nutrients and water, influence the diversity of plants at local and global scales. Disturbances such as fires can drastically change resource availability to plants. For example, ecosystems that experience frequent fires also experience surges of nitrogen availability after the fire. Although nitrogen is a crucial resource for all plants, nitrogen not captured by plants can be washed away and contribute to the pollution of streams and lakes. As such, it is important to understand how plant diversity might change if nitrogen availability changes, and subsequently how the ability of the plant community to retain nitrogen might also change. Investigators will examine whether plant communities that have experienced frequent pulses of nitrogen are better able to capture nitrogen and prevent it from leaving the ecosystem than are plant communities that have not experienced nitrogen pulses. This research will help to predict how plant communities respond to changes in nitrogen availability, and how patterns of nitrogen retention and loss are affected by fire frequency. As part of this project, one undergraduate student will gain hands-on experience in field ecology and laboratory chemical analyses. In addition, the investigators will develop teaching activities to improve understanding of N cycling at local and global scales by undergraduate students. Data from this study will be added to a database used to estimate the global carbon cycle. The findings of the study will be disseminated in peer-reviewed journals and at national conferences.This project is an empirical field test of patterns identified in greenhouse studies of interspecific differences in pulsed nitrogen assimilation. The researchers will trace the fate of nitrogen into different ecosystem compartments in a longleaf pine (Pinus palustris) forest, using isotope analysis in sites with contrasting historical fire frequencies (annual burns or fire suppression). Researchers will measure the amount of isotope stored in microbial biomass, aboveground and belowground biomass of dominant plant species, and the bulk soil pool. By comparing the amount of nitrogen stored in different compartments between sites under annual burn or fire suppression regimes, they will assess the extent to which plant communities exposed to frequent nitrogen pulses are adapted to capturing this ephemeral resource. Further, they will test whether these interspecific differences in the capacity to capture pulsed nitrogen scale up to influence ecosystem-level nitrogen retention patterns in the field. The researchers predict that shifts in community composition favoring species adapted to assimilating ephemeral nitrogen will result in increased nitrogen retention in frequently burned sites, as compared to fire-suppressed sites.

DEB-1601279 Wright，Justin P.，杜克大学：论文研究：将植物生理学扩展到生态系统生态学：评估植物群落在防止火灾后氮损失中的作用。养分和水的可用性，例如养分和水，影响当地和全球范围的植物多样性。诸如火灾之类的干扰可以大大改变对植物的资源可用性。例如，经常发生火灾的生态系统也经历了火灾后的氮供应量。尽管氮是所有植物的关键资源，但未被植物捕获的氮可以被冲走并有助于溪流和湖泊的污染。因此，重要的是要了解氮的可用性发生变化，以及随后植物群落保留氮的能力也可能改变的能力也可能发生变化，这一点很重要。研究人员将检查经常经历过氮脉冲的植物群落是否能够比没有经历氮豆类的植物群落更好地捕获氮和防止其离开生态系统。这项研究将有助于预测植物群落如何应对氮的可用性变化，以及氮的保留和损失模式如何受火频率的影响。作为该项目的一部分，一位本科生将获得现场生态学和实验室化学分析的动手经验。 此外，研究人员将开展教学活动，以提高本科生对本地和全球范围内n循环的了解。这项研究的数据将添加到用于估计全球碳周期的数据库中。该研究的发现将在同行评审的期刊和全国会议上传播。该项目是对脉冲氮同化种间差异的温室研究中鉴定出的模式的经验现场测试。研究人员将使用同位素分析在具有对比的历史火灾频率（年度燃烧或抑制火灾）的地点中，将氮的命运追溯到不同生态系统室中的不同生态系统室。研究人员将测量存储在微生物生物量，地上和地下生物量的同位素的量，以及主要的土壤池。通过比较在年度燃烧或抑制抑制条件下的地点之间不同隔室中存储的氮量，他们将评估暴露于频繁氮脉冲的植物群落的程度，可用于捕获这种短暂的资源。此外，他们将测试这些种间差异捕获脉冲氮尺度的能力的差异是否会影响该领域的生态系统水平氮保留模式。研究人员预测，与供电抑制的地点相比，社区组成的转变有利于适应替代短暂氮的物种的物种，将导致经常燃烧的部位的氮保留率增加。