Collaborative Research: MRA: Dew impacts on ecosystem carbon, energy and water fluxes at continental scale - a synthesis across NEON sites

合作研究：MRA：露水对大陆尺度生态系统碳、能量和水通量的影响 - 跨 NEON 站点的综合

• 批准号: 2307257
• 负责人: Lixin Wang
• 金额: $ 42.92万
• 依托单位: Indiana University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-01 至 2027-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2307257&HistoricalAwards=false
• 关键词: Collaborative; Research; MRA; Dew; impacts

The processes that control carbon and water flows through vegetation are critical land surface feedbacks on a changing climate. While often overlooked, dew formation can generate up to a 25% reduction in the transpiration flux and may improve plant tolerance of drought or heat stress in xeric systems or during dry periods in mesic systems. Furthermore, dew affects the uptake and exchange of gases across the stomata potentially limiting carbon gain, influences plant susceptibility to some pathogen infections, and supports epiphyte communities. Placing a constraint on the importance of dew to these ecosystem processes is critical since larger, but less frequent, rain events and drier air are expected under warming and may generate broad declines in dew inputs. This project will provide the first comprehensive, macroscale assessment of dew impacts on carbon, energy, and water fluxes across xeric to hydric ecosystems. It will generate a new module for dew implementation in land surface models, enabling further investigations of the impacts of dew in research areas ranging from weather forecasting to microbiology. The project will support the development of a new field-based study abroad program on climate and ecosystem resilience in Puerto Rico where students will participate in fieldwork at NEON sites and take part in workshops and discussions with local scientists. The project will support up to 36 undergraduate students for this, who will be recruited primarily from a minority-serving institution. The project will also support an early career female faculty member as PI, train three PhD students and eight high school students. The formation of dew is a ubiquitous phenomenon that can be an almost daily occurrence in some ecosystems. Dew has a measurable impact on carbon and water fluxes by suppressing transpiration, reducing carbon exchange, and impacting the temperature, albedo, and local vapor pressure deficit (VPD) of the canopy. However, previous work has largely focused on discrete campaigns in arid environments at the leaf or plant level. Here, the first standardized continuous canopy-scale measurement of dew will be generated using infrared radiometry, canopy water content estimates from GPS receivers, and leaf wetness sensors across a hydric to xeric gradient encompassed by the NEON network. The observations will be used for the direct assessment of dew impacts on ecosystem fluxes and for the development and implementation of an ecosystem model that accounts for the effects of dew on surface soil moisture, foliar water uptake, and energy balance. This project will provide fundamental insights into dew impacts on ecosystem processes and a critical constraint on how dew reduction associated with rising temperatures and VPD may exacerbate ecosystem water stress.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.

控制碳和水流过植被的过程是气候变化的关键地表反馈。虽然经常被忽视，但露水的形成可以使蒸腾通量减少高达 25%，并且可以提高植物对旱地系统或中湿系统干旱期间的干旱或热应激的耐受性。此外，露水会影响气孔中气体的吸收和交换，从而可能限制碳的增加，影响植物对某些病原体感染的敏感性，并支持附生植物群落。限制露水对这些生态系统过程的重要性至关重要，因为在气候变暖的情况下，预计会出现规模更大但频率较低的降雨事件和干燥的空气，并可能导致露水输入的大幅下降。该项目将首次对露水对旱地至氢生态系统中碳、能量和水通量的影响进行全面、宏观的评估。它将生成一个用于在地表模型中实现露水的新模块，从而能够进一步调查露水对天气预报和微生物学等研究领域的影响。该项目将支持在波多黎各开发一个关于气候和生态系统复原力的新的实地考察项目，学生将参加 NEON 站点的实地考察，并参加与当地科学家的研讨会和讨论。该项目将为此支持最多 36 名本科生，他们将主要从少数族裔服务机构中招募。该项目还将支持一名早期职业女教师担任 PI，培训三名博士生和八名高中生。露水的形成是一种普遍存在的现象，在某些生态系统中几乎每天都会发生。露水通过抑制蒸腾作用、减少碳交换以及影响树冠的温度、反照率和局部蒸气压赤字 (VPD)，对碳和水通量产生可测量的影响。然而，以前的工作主要集中在干旱环境中叶子或植物层面的离散活动。在这里，第一个标准化的连续冠层规模的露水测量将使用红外辐射测量、GPS 接收器的冠层含水量估计值和 NEON 网络涵盖的氢气到干燥梯度的叶片湿度传感器来生成。这些观测结果将用于直接评估露水对生态系统通量的影响，并用于开发和实施生态系统模型，该模型考虑了露水对表层土壤湿度、叶面吸水和能量平衡的影响。该项目将提供有关露水对生态系统过程影响的基本见解，以及与气温升高和 VPD 相关的露水减少如何加剧生态系统水压力的关键限制。该奖项反映了 NSF 的法定使命，并通过使用基金会的评估进行评估，被认为值得支持。智力价值和更广泛的影响审查标准。