The Dynamics of Nonstructural Carbon in Perennial Plants

多年生植物中非结构碳的动态

• 批准号: 0726332
• 负责人: Claudia Czimczik
• 金额: --
• 依托单位: University of California-Irvine
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-08-15 至 2011-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0726332&HistoricalAwards=false
• 关键词: Dynamics; Nonstructural; Carbon; Perennial; Plants

Plants transport, accumulate, and store the products of photosynthesis as nonstructural carbon (NSC), mainly in form of sugars and starch. These compounds provide energy for growth and maintenance of plant tissues, as well as for defense, reproduction and symbiosis. Existing research indicates that NSC plays a role in a plant's ability to compete and survive damage or stress. NSC also represents a significant fraction of a plant's annual C budget, contributing to interannual variation in stand-level productivity. Currently, models of NSC in plants are conceptual rather than quantitative, because we do not know how long C resides in these important forms. This project will use radiocarbon to measure the ages of starch and sugars extracted from stem wood as well as stem-respired CO2 in co-existing evergreen and deciduous oak trees (genus Quercus L.) in California. Oaks were chosen for their importance, for their different life strategies in the same climate situation, and because limits to their resilience will help determine their ability to survive disease and drought stress. NSC pools are predicted to be oldest where climate is least predictable (i.e. at the extremes of the species' ranges), and youngest where climate varies least from one year to the next. The role of NSC in plant survival will be explored by studying the age of CO2 respired by plants subjected to stresses like drought or defoliation (herbivory). The coming century will likely see increases in the stresses to which plants are exposed through climate change and increases in herbivory, fire or competition with invaders. NSC provides a major mechanism for plants to cope with stress and damage. The measurements made in this project will directly assess whether there are longer-term NSC stores accessible to plants, and the degree to which they use these stores to survive adverse conditions. Broader impacts. The project has significant potential to increase our understanding of forest carbon pools and turnover. This is important in understanding plant response to climate change and in the earth's overall carbon budget. The project will support the training of graduate and undergraduate students in research. Members of a summer Research Experiences for Undergraduates program will participate and learn about the research. A summer course on the uses of radiocarbon in ecology that is the only one of its kind in the country is offered annually by the PI.

植物以非结构碳(NSC)的形式运输、积累和储存光合作用的产物，主要以糖和淀粉的形式存在。这些化合物为植物组织的生长和维持以及防御、繁殖和共生提供能量。现有的研究表明，NSC在植物的竞争能力和生存能力中起着重要作用。NSC也代表了工厂年度碳预算的很大一部分，导致了林分水平生产力的年际变化。目前，植物中的NSC模型是概念性的，而不是定量的，因为我们不知道C在这些重要形式中停留了多长时间。该项目将使用放射性碳来测量从树干木材中提取的淀粉和糖的年龄，以及共存的常绿和落叶橡树(Quercus L.)树干呼吸的二氧化碳。在加利福尼亚州。之所以选择橡树，是因为它们的重要性，因为它们在相同气候条件下的不同生活策略，以及因为它们弹性的限制将有助于确定它们在疾病和干旱压力下生存的能力。据预测，NSC池最古老的地方是气候最难预测的地方(即在物种范围的极端)，最年轻的地方是气候变化最小的年份。NSC在植物存活中的作用将通过研究植物在干旱或落叶(食草性)等胁迫下呼吸二氧化碳的年龄来探索。在接下来的一个世纪里，由于气候变化，植物面临的压力可能会增加，食草、火灾或与入侵者竞争的情况也会增加。NSC为植物提供了应对逆境和伤害的主要机制。这个项目中所做的测量将直接评估是否有植物可以接触到的较长期的NSC商店，以及它们利用这些商店在不利条件下生存的程度。更广泛的影响。该项目有很大的潜力增加我们对森林碳库和周转的了解。这对于了解植物对气候变化的反应和地球的整体碳预算是很重要的。该项目将支持研究生和本科生的研究培训。本科生暑期研究体验计划的成员将参与并了解这项研究。该协会每年都会举办一期关于放射性碳在生态学中的使用的夏季课程，这是该国唯一的此类课程。