RII Track-4: NSF: Does warming-driven root damage lead to drought stress in declining yellow-cedar trees?

RII Track-4：NSF：变暖导致的根部损伤是否会导致黄雪松树衰退的干旱胁迫？

• 批准号: 2132217
• 负责人: Benjamin Gaglioti
• 金额: $ 11.3万
• 依托单位: University of Alaska Fairbanks Campus
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-02-01 至 2025-01-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2132217&HistoricalAwards=false
• 关键词: RII; Track; NSF; Does; warming; RII; Track; NSF; Does; warming

Yellow-cedar (Callitropsis nootkatensis) is now experiencing widespread dieback in the temperate rainforests of northwestern North America. Significant evidence supports the idea that a loss of insulating snow cover caused by global warming exposes yellow-cedar (YC) roots to frost damage, which eventually leads to tree death. The purpose of this project is to better understand how climate change is affecting yellow-cedar (YC), an iconic tree species in widespread decline. To date, over 3,000 km2 of YC forests have experienced significant dieback, which has had far-reaching economic, ecological, and cultural effects in Southeast Alaska and British Columbia. Yellow-cedar is now considered a “poster child” of the global trend of declining forest health in response to anthropogenic warming, and successful YC conservation efforts will hinge on identifying all the links between climate change and tree death. Drought stress in the aftermath of frost damage to YC roots during periods of anomalous, late-winter weather is an untested yet potentially critical link in the dieback process. Through a collaboration between the University of Alaska Fairbanks (UAF) and the University of Arizona, this project will test whether declining YC trees exhibit symptoms of drought stress by applying newly developed methods to analyze cedar wood anatomy. In addition to peer-reviewed publications and conference presentations led by an early-career researcher, this project will involve a week-long workshop with K-12 students and forest managers in the Alaska Native community of Kake. The primary goal of this project is to test an important corollary of the “frost-damaged root” hypothesis; namely, that YC root injury results in drought stress and eventual tree mortality. To avoid cavitation, drought-stressed conifer trees lay down thinner-diameter and thicker-walled tracheid cells within their annual rings, and these anatomical changes can be documented using new methods in quantitative wood anatomy (QWA). This project will use these methods to test the prediction that tracheid cells in the outer rings of declining and dead YC trees have significantly lower lumen areas and thicker walls relative to the same annual rings grown in nearby healthy YC trees. To accomplish this, the investigator from UAF will work with a collaborator at the Laboratory of Tree-Ring Research at the University of Arizona to apply QWA methods on long dead, actively declining, and currently healthy YC trees collected from Southeast Alaska. These results will provide new insight about climate change and forest dieback and will allow stakeholders to predict the impacts of frost damage and drought more accurately on this important tree species. In addition, this project will expand research infrastructure at UAF by acquiring new analytical methods that will benefit an array of environmental research in Alaska.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.

黄-Cedar（Callitropsis nootkatensis）现在在北美西北部的温度雨林中经历了宽度的死亡。大量证据支持这样的想法，即由于全球​​变暖引起的绝缘积雪损失暴露了黄核（YC）的根部造成霜冻损害，这有时会导致树死亡。该项目的目的是更好地理解气候变化如何影响黄-Cedar（YC），这是一种标志性的树种，处于宽度下降。迄今为止，超过3,000公里的YC森林经历了重大的死亡，在阿拉斯加东南部和不列颠哥伦比亚省的经济，生态和文化影响深远。现在，黄核被认为是响应人为变暖的森林健康趋势下降的全球趋势的“海报孩子”，成功的YC保护工作将取决于识别气候变化与树木死亡之间的所有联系。在异常，冬季天气中，在霜冻根部造成霜冻损害后，干旱压力是未经测试但潜在的至关重要的联系。通过阿拉斯加大学Fairbanks（UAF）与亚利桑那大学之间的合作，该项目将通过应用新开发的方法来分析雪松木解剖结构来测试YC树的下降是否暴露了干旱压力的症状。除了由早期研究员领导的经同行评审的出版物和会议演讲外，该项目还将涉及与阿拉斯加凯克（Kake）阿拉斯加土著社区的K-12学生和森林经理进行的为期一周的研讨会。该项目的主要目的是检验“霜冻损坏的根”假设的重要推论。也就是说，YC根部损伤会导致干旱压力和最终的树木死亡率。为了避免空气，干旱压力的针叶树在年度环内放置较薄的直径和较厚的气管细胞，并且可以使用定量木材解剖学（QWA）的新方法记录这些解剖学变化。该项目将使用这些方法来测试以下预测：相对于在附近健康YC树中种植的相同年度环相对于相同的年度环，衰减和死YC树的外环和死亡YC树的外环和较厚的墙壁的预测明显降低。为此，UAF的调查员将与亚利桑那大学树林研究实验室的合作者合作，将QWA方法应用于长期死亡，积极下降，目前从阿拉斯加东南部收集的健康YC树。这些结果将提供有关气候变化和森林消失的新见解，并使利益相关者能够更准确地预测霜冻损害的影响，并对这种重要的树种进行更准确的影响。此外，该项目将通过获取新的分析方法来扩大UAF的研究基础设施，这些方法将使阿拉斯加的一系列环境研究受益。该奖项反映了NSF的法定任务，并被认为是通过基金会的智力优点和更广泛的影响审查标准通过评估而被认为是珍贵的支持。