Collaborative Research: Understanding Ozone-Ecosystem Controls and Feedbacks across Landscapes through Leaf- and Canopy-Scale Measurements

合作研究：通过叶子和冠层尺度的测量了解臭氧生态系统对景观的控制和反馈

• 批准号: 1837891
• 负责人: Sally Pusede
• 金额: $ 36.66万
• 依托单位: University of Virginia Main Campus
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-11-01 至 2022-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1837891&HistoricalAwards=false
• 关键词: Collaborative; Research; Understanding; Ozone; Ecosystem

This research will help to develop a better understanding of the processes that influence tropospheric ozone variability in forested regions. New analytical tools will be used to collect comprehensive observations of the atmosphere-canopy exchange of gases and the associated ecological response to ozone. The interdisciplinary team of scientists who are leading this effort have expertise in atmospheric chemistry, landscape and organismal ecology, and land-atmosphere exchange, as well as broad experimental expertise in advanced instrumentation design and use in field and laboratory settings. The results of this project have the potential to improve air quality modeling by better representing ecosystem feedbacks to ozone pollution. The team of scientists plan to collect two years of continuous data at the Virginia Forest Laboratory (VFL) in central Virginia, coupling ozone flux measurements with observations of canopy-level photosynthesis by solar induced fluorescence (SIF), isomer-resolved ozone-reactive biogenic organic compounds (BVOCs), and critical ecosystem parameters of canopy conductance and carbon dioxide exchange. These same variables will be measured by analogous instrumentation in leaf-scale laboratory experiments using plant species prominent at the VFL under the range of typical local environmental conditions, in which perturbations will be induced to test for ecosystem feedbacks.The three hypotheses to be tested are: (1) Interactions between ozone flux to the canopy and the SIF technique, that directly detects fluorescence of chlorophyll molecules, are directly measurable, are independent from interactions between ozone flux and stomatal conductance and have a distinguishable effect on the ozone lifetime; (2) Ozone flux to the canopy is often controlled by sparsely measured but highly reactive BVOCs. Variability in ozone flux to the canopy caused by these BVOCs can be quantified by their molecular identities and concentrations; (3): Uptake of ozone by plants leads to one or more of 3 detectable and significant ozone-ecosystem feedbacks: (a) ozone uptake reduces stomatal conductance, leading to longer ozone lifetimes against plant uptake; (b) ozone uptake reduces canopy BVOC concentrations by impairing photosynthesis, leading to longer ozone lifetimes against within-canopy chemical oxidation; and (c) ozone uptake enhances BVOC emissions, leading to shorter ozone lifetimes against within-canopy chemical oxidation. The results of this research are expected to produce new observational constraints on relationships between atmospheric composition and ecosystem function.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.

这项研究将有助于更好地了解影响森林地区对流层臭氧变化的过程。 新的分析工具将用于收集对大气层-冠层气体交换以及对臭氧的相关生态反应的综合观测。领导这项工作的跨学科科学家团队拥有大气化学、景观和生物生态学以及陆地-大气交换方面的专业知识，以及先进仪器设计和现场和实验室环境使用方面的广泛实验专业知识。该项目的结果有可能通过更好地代表生态系统对臭氧污染的反馈来改进空气质量建模。科学家团队计划在弗吉尼亚州中部的弗吉尼亚森林实验室（VFL）收集两年的连续数据，将臭氧通量测量与通过太阳诱导荧光（SIF）、异构体解析的臭氧反应性生物源对冠层光合作用的观测结合起来有机化合物（BVOC），以及冠层电导和二氧化碳交换的关键生态系统参数。 这些相同的变量将通过叶尺度实验室实验中的类似仪器进行测量，使用在典型当地环境条件范围内 VFL 突出的植物物种，其中将诱导扰动来测试生态系统反馈。要测试的三个假设是： (1) 到达冠层的臭氧通量与直接检测叶绿素分子荧光的 SIF 技术之间的相互作用是可直接测量的，独立于臭氧通量与气孔导度之间的相互作用，并且具有可区分性对臭氧寿命的影响； (2) 流向冠层的臭氧通量通常由测量稀疏但反应性高的 BVOC 控制。由这些 BVOC 引起的到达冠层的臭氧通量的变化可以通过它们的分子特性和浓度来量化； (3)：植物对臭氧的吸收导致 3 种可检测到的重要臭氧生态系统反馈中的一种或多种： (a) 臭氧吸收降低了气孔导度，导致植物吸收的臭氧寿命更长； (b) 臭氧吸收通过损害光合作用来降低冠层 BVOC 浓度，从而延长臭氧寿命以抵抗冠层内的化学氧化； (c) 臭氧吸收增加了 BVOC 排放，导致臭氧针对树冠内化学氧化的寿命缩短。 这项研究的结果预计将对大气成分与生态系统功能之间的关系产生新的观测约束。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值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

Measurement report: Variability in the composition of biogenic volatile organic compounds in a Southeastern US forest and their role in atmospheric reactivity

测量报告：美国东南部森林中生物挥发性有机化合物成分的变化及其在大气反应中的作用

• DOI: 10.5194/acp-21-15755-2021
• 发表时间: 2021
• 期刊: Atmospheric Chemistry and Physics
• 影响因子: 6.3
• 作者: McGlynn, Deborah F.;Barry, Laura E.;Lerdau, Manuel T.;Pusede, Sally E.;Isaacman-VanWertz, Gabriel
• 通讯作者: Isaacman-VanWertz, Gabriel

Gap models across micro- to mega-scales of time and space: examples of Tansley’s ecosystem concept

• DOI: 10.1186/s40663-020-00225-4
• 发表时间: 2020-03
• 期刊: Forest Ecosystems
• 影响因子: 4.1
• 作者: H. Shugart;A. Foster;Bin Wang;D. Druckenbrod;Jianyong Ma;M. Lerdau;S. Saatchi;Xi Yang;Xiaodong Yan

Mapping Temperate Forest Phenology Using Tower, UAV, and Ground-Based Sensors

• DOI: 10.3390/drones4030056
• 发表时间: 2020-09
• 期刊: Drones
• 影响因子: 4.8
• 作者: J. Atkins;A. Stovall;Xi Yang