CAREER: Interactive Effects of Land Cover and Climate Change on Forest Carbon Sequestration: Integration of Research and Education to Advance Fundamental Science and Inclusivity

该奖项全部或部分由《2021年美国救援计划法案》（公法117-2）资助。温带森林从大气中吸收的二氧化碳比任何其他陆地生态系统都多，因此在减缓气候变化速度方面发挥着关键作用。然而，温带森林也是世界上破碎程度最严重的森林生物群落。城市化和农业扩张导致的森林砍伐造成了树木生长条件空间梯度较大的异质景观。森林边缘的树木比森林内部的树木生长得更快，但受到高温和干旱等极端天气的负面影响更大。为什么破碎森林中的树木生长受到气候压力的负面影响比完整森林中的更大，其机制尚不清楚。科学界对气候如何影响树木生长和森林碳固存的理解，主要是基于对远离森林边缘的内部森林生态系统的研究。过去对内陆森林的关注限制了我们对受破碎化影响的温带森林中大量且日益增长的碳循环的理解。本研究采用野外实验和模型相结合的方法，研究了森林破碎化和气候对树木生长和森林碳汇的交互影响。该项目旨在改变我们对气候和土地覆盖持续变化的世界中温带森林未来固碳能力的看法，从而为气候变化缓解战略提供信息。这项工作与旨在解决环境生物学纳入的主要障碍和改善学术界与利益相关者之间沟通的倡议相配合，包括让少数民族学生和高中教师参与研究，以及与学术界、教育工作者和森林管理者举办讲习班。这项工作的目标是建立对森林破碎化和气候对森林碳封存的相互作用的机制理解，以及这些相互作用在调节人类主导景观中的碳平衡中所起的作用。这些目标将通过在边缘影响和温带内部阔叶林中建立一项操纵降水制度（即环境降水、高降水和干旱）的新实验来实现。该实验还将利用自然发生的气温随时间的变化，探索森林破碎化和水分有效性在森林对过热的碳固存响应中的作用。该实验产生的数据将用于修改现有的地球系统模型（能源百亿亿次地球系统模型），以改进对人类景观和气候变化响应中森林碳循环的描述。该奖项反映了美国国家科学基金会的法定使命，并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，被认为值得支持。

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2).Temperate forests remove more carbon dioxide from the atmosphere than any other terrestrial ecosystem and thus play a critical role in slowing the rate of climate change. However, temperate forests are also the most heavily fragmented forest biome in the world. Deforestation from urbanization and agricultural expansion creates heterogeneous landscapes with large spatial gradients in growing conditions for trees. Trees at the forest edge grow faster than those in the forest interior, yet are more negatively impacted by extreme weather like high temperatures and drought. The mechanisms explaining why tree growth in fragmented forests is more negatively impacted by climate stress than in intact forests remain unknown. The scientific community’s understanding of how climate affects tree growth and forest carbon sequestration are largely based on studies from interior forest ecosystems, away from forest edges. This past focus on interior forests limits our understanding of carbon cycling across the large and growing proportion of temperate forests that is influenced by fragmentation. This study integrates a field experiment and modeling to test the interactive effects of forest fragmentation and climate on tree growth and forest carbon sequestration. The project is intended to transform how we think about the future of the temperate forest’s capacity to sequester carbon in a world facing ongoing changes in climate and land cover and thus will inform climate change mitigation strategies. This work is paired with initiatives aimed at addressing major barriers to inclusion in environmental biology and improving communication between academics and stakeholders, including engaging minority students and high school teachers in research and holding workshops with academics, educators, and forest managers. The goals of the proposed work are to develop a mechanistic understanding of the interactive effects of forest fragmentation and climate on forest carbon sequestration and the role these interactions play in modulating carbon balance across human-dominated landscapes. These goals will be accomplished by establishing a new experiment to manipulate precipitation regimes (i.e., ambient precipitation, high precipitation, and drought) in both edge-influenced and interior temperate broadleaf forests. This experiment will also leverage naturally occurring variations in air temperature across time to explore the roles of forest fragmentation and water availability in forest carbon sequestration response to excessive heat. Data generated from this experiment will be used to modify an existing Earth system model (the Energy Exascale Earth System Model) to improve depictions of forest carbon cycling across human-landscapes and in response to climate change.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.