Collaborative Research: Alternative leaf water use strategies in hot environments

合作研究：炎热环境下的替代叶水利用策略

基本信息

批准号：
2140429
负责人：
Luiza Maria Teophilo Aparecido
金额：
$ 10.72万
依托单位：
Arizona State University
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2022
资助国家：
美国
起止时间：
2022-07-01 至 2023-09-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=2140429&HistoricalAwards=false
关键词：
Collaborative Research Alternative leaf water

项目摘要

Heat waves are impairing global forest productivity, ecosystem biodiversity and crop yields. In hot environments where leaf functioning is vulnerable to high temperatures, plants must cool leaves to avoid heat damage. This cooling might occur even when plants cannot photosynthesize, which is counter to the commonly understood benefit to plants of using water. However, the prevalence of these alternative water use strategies remains unknown, despite the important implications they have for understanding local, regional and global carbon and water cycles. This project will quantify alternative water use behavior across a broad range of species to determine whether this prioritization of cooling over photosynthesis is common. In turn, results will improve efforts to model vegetation responses to heat waves and identify species that are potentially best suited to cope with heat stress. The project will contribute to the training of early career scientists, graduate students, and undergraduate students in modern plant and environmental science research. Public outreach will focus on developing an outdoor exhibit for the Desert Botanical Garden, a public facility that receives approximately 500K visitors per year. The bilingual display will demonstrate to visitors the physiological and societal costs of heat waves on plants and the ways in which plants regulate their temperatures.Episodic heat waves that are increasing in duration, frequency and intensity will likely amplify plant thermal stress and mortality. Therefore, plants occurring in hot environments must cool leaves below a critical threshold that can result in permanent leaf damage. Contrary to stomatal regulation models, transpiration can achieve this cooling independent of changes in photosynthesis when conditions are thermally stressful. Recent studies have reported such alternative water use strategies in several species, which then do not maximize carbon gain for a fixed level of stomatal conductance or hydraulic risk. This project combines tightly controlled leaf gas exchange measurements with experimental manipulation of environments, and a hierarchical modeling framework in order to (1) determine the prevalence of alternative water use strategies across a diverse set of species, (2) determine the traits that best predict this behavior, (3) develop optimality theory to predict under what environmental conditions this behavior should occur, and (4) validate predictions along a broad desert – montane elevation gradient. Results will advance theory for stomatal regulation, a core topic in the fields of plant ecology and Earth system modeling. It will also provide one of the largest and most standardized datasets for plant responses to extreme environmental conditions, yielding a data resource of high value to other investigators. These findings can then be used to directly inform a revised representation of plant water use in Earth System Models. This representation will ultimately yield more useful predictions under climate change scenarios.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

热浪损害了全球森林生产率，生态系统生物多样性和作物产量。在叶片功能容易受到高温的热环境中，植物必须冷却叶子以避免热损伤。即使植物无法光合作用，这种冷却也可能发生，这与使用水的植物所理解的好处相对应。但是，这些替代用水策略的普遍性仍然未知，戈德斯特人对理解本地，区域和全球碳和水周期的重要意义。该项目将量化广泛物种的替代用水行为，以确定冷却优先级优先于光合作用。反过来，结果将改善对热浪的植被反应建模的努力，并确定最适合应对热应激的物种。该项目将有助于对现代植物和环境科学研究的早期职业科学家，研究生和本科生的培训。公众推广将着重于为沙漠植物园开发户外展览，该展览会每年接待大约50万名游客的公共设施。双语展示将向游客展示植物上热浪的生理和社会成本以及植物调节温度的方式。持续时间，频率和强度在增加的剧烈热浪可能会扩大植物的热压力和死亡率。因此，在炎热环境中发生植物必须冷却在临界阈值以下的叶子，这可能会导致永久性叶子损伤。与气孔调节模型相反，蒸腾作用可以实现这种冷却，而不是在热压力时光合作用的变化而不是光合作用的变化。最近的研究报告了几种物种中这种替代用水策略，然后在固定水平的气孔电导或氢化风险中不会最大化碳增益。该项目将紧密控制的叶气交换测量与对环境的实验操作结合在一起，以及一个分层建模框架，以（1）确定在一组潜水物种集合中替代替代用水策略的普遍性，（2）确定最佳预测这种行为的特征，（3）在哪些环境条件下预测这种行为应在哪些环境条件下进行，并逐步逐步预测（4）的范围（4）逐步预测一定的预测。结果将推进气门调节的理论，这是植物生态和地球系统建模领域的核心主题。它还将为对极端环境条件的植物响应提供最大，最标准化的数据集之一，从而为其他研究人员提供高价值的数据资源。然后，这些发现可用于直接告知地球系统模型中植物用水的修订代表。该奖项最终将在气候变化情景下产生更有用的预测。该奖项反映了NSF的法定使命，并通过使用基金会的知识分子优点和更广泛的影响评估标准来诚实地通过评估来诚实地支持。