CAREER: Understanding the importance of biomass hydraulic capacitance for transpiration

职业：了解生物质水力电容对于蒸腾作用的重要性

• 批准号: 2046768
• 负责人: Ashley Matheny
• 金额: $ 67.8万
• 依托单位: University of Texas at Austin
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-02-01 至 2026-01-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2046768&HistoricalAwards=false
• 关键词: CAREER; Understanding; importance; biomass; hydraulic

Forests provide an important link between the water cycle and the carbon cycle. Increasing global temperature and chances of drought threaten the forest ecosystems. Droughts can limit the ability of trees to cycle carbon and water due to limited amount of water in the soil and atmosphere. Like many plans, trees move water from the soil into the roots, up through trunks and branches, and out through the leaves into the atmosphere. They can move and store large amounts of water that play a key role on maintaining plant functions and prevent drought stress. Bigger trees typically have larger volumes of water storage, protecting them from soil water stress. This study assesses the role of forest water storage in how trees respond to water supply and demand stresses in a temperate and a semi-arid forest. The work will develop a new sensor to measure water content in trees and generate an extensive dataset of water content in living, mature trees that will advance knowledge on how different trees acquire, store, and use water. It will further develop computer models to simulate the effects of forest water storage on the water and carbon cycles and apply new satellite data analysis to assess where the water is residing and predict the likelihood of droughts, tree mortality, and forest fires. An interactive virtual field trip of different forests will be developed, both in English and Spanish, to increase access to field experience and expand diversity in the Earth sciences. The central goal of this research is to increase understanding of the physics of water storage and use in trees. This novel understanding of capacitance will be used to develop plant hydraulics models and to connect individual-based ground measurements of biomass water storage to remotely sensed data products at regional and global scales for use in model evaluation, as well as to generate predictions of ecosystem stress. This research effort will couple field-based observations and instrumentation development with model development and evaluation. Measurements of biomass water storage, water potential, and sap flux will be used to create individual-based plant hydraulics models capable of reproducing the capacitive response to rewetting after drought. These data will also be used to ground truth regional-scale remotely sensed biomass water content using a statistical scaling algorithm. Finally, this work will provide a pathway to incorporate remote sensing observations of water content into plant hydraulics-capable land-atmosphere models at the regional scale. This research will shed new light on the role biomass water storage plays in governing transpiration response to VPD and soil water stresses and will enhance our ability to model vegetation responses to both drought stress and drought recovery at multiple scales. Simultaneously to these research activities, interactive digital field trips will be created to allow students at high school and college levels to immerse themselves with the scientific team to learn more about carbon, water, and energy cycling in different forest types.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.

森林是水循环和碳循环之间的重要纽带。全球气温上升和干旱的可能性威胁着森林生态系统。由于土壤和大气中的水分有限，干旱会限制树木循环碳和水的能力。像许多计划一样，树木将水分从土壤中转移到根部，通过树干和树枝向上移动，然后通过树叶进入大气。它们可以移动和储存大量的水分，这些水分在维持植物功能和防止干旱胁迫方面发挥着关键作用。大树通常有更大的储水量，保护它们免受土壤水分压力的影响。这项研究评估了森林蓄水在温带和半干旱森林中树木对水分供需压力的反应中的作用。这项工作将开发一种新的传感器来测量树木的水分含量，并生成一个关于活的成熟树木水分含量的广泛数据集，这将促进对不同树木如何获取、储存和使用水分的了解。它将进一步开发计算机模型，以模拟森林蓄水对水和碳循环的影响，并应用新的卫星数据分析来评估水在哪里存在，并预测干旱、树木死亡和森林火灾的可能性。将用英语和西班牙语开展不同森林的互动虚拟实地考察，以增加实地经验和扩大地球科学的多样性。这项研究的中心目标是增加对树木中水分储存和使用的物理学的了解。这种对电容的新理解将被用于开发植物水力学模型，并将生物质水储存的基于个人的地面测量与区域和全球尺度的遥感数据产品联系起来，用于模型评估，以及产生生态系统压力的预测。这项研究工作将把现场观测和仪器开发与模型开发和评估结合起来。生物质储水量、水势和树液通量的测量将被用来创建基于个体的植物水力学模型，能够再现干旱后复湿的电容响应。这些数据还将用于利用统计比例算法对真实的区域尺度遥感生物质水含量进行地面测量。最后，这项工作将提供一种途径，将水分含量的遥感观测纳入区域尺度上具有植物水力学能力的陆地-大气模型。这项研究将揭示生物质水储存在调节蒸腾对VPD和土壤水分胁迫的响应中所起的作用，并将增强我们在多个尺度上模拟植被对干旱胁迫和干旱恢复的响应的能力。在这些研究活动的同时，将创建互动的数字实地考察，让高中和大学水平的学生沉浸在科学团队中，了解更多关于不同森林类型的碳、水和能源循环的知识。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Stressors Reveal Ecosystems' Hidden Characteristics

• DOI: 10.1029/2021jg006462
• 发表时间: 2021-07
• 期刊: Journal of Geophysical Research: Biogeosciences
• 作者: A. Matheny

Tree hydrodynamic modelling of the soil–plant–atmosphere continuum using FETCH3

使用 FETCH3 对土壤 - 植物 - 大气连续体进行树木流体动力学建模

• DOI: 10.5194/gmd-15-2619-2022
• 发表时间: 2022
• 期刊: Geoscientific Model Development
• 影响因子: 5.1
• 作者: Silva, Marcela;Matheny, Ashley M.;Pauwels, Valentijn R.;Triadis, Dimetre;Missik, Justine E.;Bohrer, Gil;Daly, Edoardo
• 通讯作者: Daly, Edoardo

Intra‐Specific Variability in Plant Hydraulic Parameters Inferred From Model Inversion of Sap Flux Data

• DOI: 10.1029/2021jg006777
• 发表时间: 2022-05
• 期刊: Journal of Geophysical Research: Biogeosciences
• 作者: Yaojie Lu;Brandon P. Sloan;S. Thompson;A. Konings;G. Bohrer;A. Matheny;Xue Feng