CAREER: Illuminating how plant water-use strategies mediate ecosystem response to multiple climate extremes

预计气候变化将给包括美国西部在内的地球仪许多地区带来更频繁和更严重的干旱。虽然在了解森林如何应对个别干旱方面取得了重大进展，但对多种干旱事件的长期反应尚不清楚。因此，森林对严重干旱等多种极端气候的反应是未知的，但对于预测未来森林健康和气候变化中的复原力至关重要。这项研究将结合联合收割机温室实验，成熟森林的实地测量，长期森林地块和遥感数据，以量化树木和森林如何应对多重干旱。研究活动将与广泛的教育活动相结合，以实现三个目标：1）为三个社区非营利组织开发本科生社区参与学习项目，2）将学生学习项目与科学参与活动相结合，以扩大科学，技术，工程和数学的参与，3）在研究活动中培养本科生和研究生。该项目将与土地管理者和美国林务局建立互动和互动的合作关系，以改善森林管理和应对气候变化的能力。极端气候对未来世纪的森林健康构成了根本性的威胁，但支配树木反应和生态系统通量的生理过程仍然难以捉摸。特别是，了解连续干旱在组织，树木和生态系统尺度上的累积影响仍然具有挑战性，因为各种各样的个人和相互作用的机制，可以增加或减少弹性。该项目将使用温室实验，田间性状和人口统计测量，长期监测网络和遥感数据的组合，从单个树木到生态系统的各个尺度量化这些驱动因素。这项研究将开发和发现有关植物水力学生理学的新信息，以应对多个干旱事件，解释美国西南部个别植物，种群和物种的变化。该项目将解决介导对极端气候反应的非线性生理和人口过程的缩放问题。因此，该项目将提供一个在不断变化的气候中预测和管理森林对多种干旱的反应的能力的进步。该奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的知识价值和更广泛的影响审查标准进行评估的支持。

Climate change is expected to bring more frequent and more severe droughts in many regions of the globe including the western United States. While important strides have been made in understanding how forests respond to individual droughts, the long-term response to multiple drought events is unclear. Thus, the response of forests to multiple climate extremes like severe drought is unknown but critical for predicting future forest health and resilience in a changing climate. This research will combine greenhouse experiments, field measurements of mature forests, long-term forest plots, and remote-sensing data to quantify how trees and forests respond to multiple droughts. The research activities will be integrated with a wide array of education activities to achieve three goals: 1) develop undergraduate community-engaged learning projects for three community non-profit organizations, 2) integrate student learning projects with science engagement activities to broaden participation in science, technology, engineering and mathematics, and 3) train undergraduate and graduate students in research activities. The project will establish an iterative and interactive engagement with land managers and the US Forest Service to improve forest management and resilience in a changing climate. Climate extremes pose a fundamental threat to forest health in the coming century, but the physiological processes that govern tree responses and ecosystem fluxes remain elusive. In particular, understanding the cumulative effects of successive droughts at the tissue, tree, and ecosystem scales remains challenging due to a wide array of individual and interacting mechanisms that can either increase or decrease resilience. This project will quantify these drivers across scales from individual trees to ecosystems using a combination of greenhouse experiments, field trait and demography measurements, long-term monitoring networks, and remote-sensing data. This research will develop and discover novel information about the physiology of plant hydraulics in response to multiple drought events, accounting for variation within individual plants, populations, and species across the southwestern United States. The project will tackle the scaling of the non-linear physiological and demographic processes that mediate responses to climate extremes. Thus, the project will provide an advance in the ability to predict and manage forest responses to multiple droughts in a changing climate.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.