A Fieldweek Approach to Determine the Drivers of Forest Stress in the Greater Yellowstone Ecosystem: Absaroka Mountains, Wyoming July 2018, 2019, 2020

北美树木年代学野外周（NADEF）是一项为期10天的年度野外活动，旨在教授树木年代学工具，为学生和专业人士提供交流机会，并将树木年代学记录的好处扩展到森林管理者。对NADEF的支持将促进新的活动，重点是了解全球森林死亡率增加背后的机制，全球森林死亡率的增加比前几个世纪所记录的更为普遍。了解这种森林死亡背后的机制对于制定明智、及时和科学驱动的管理措施来应对这些死亡事件至关重要。实地周将在三年期间为大约120名参与者提供专业发展，同时向参与者传授维持这些森林所需的管理信息。实地周将继续其在扩大树木年代学学者的性别和种族多样性方面的良好记录。来自代表性不足群体的学生将有机会获得本科奖学金，研究生研究奖学金将帮助教育和培训学生以专业的方式展示实地研究周的发现。NADEF有25年的历史，汇集了不同群体的学者学习前沿的树木年代学科学，以不断提高林业科学研究和更好地管理森林资源。在这一系列的实地考察周中，参与者将参与五个研究项目，重点是完成火灾历史、昆虫爆发重建、气候重建、跨海拔梯度的林分结构分析，以及年代学，即检查蛤和鱼耳骨等骨骼结构的年轮。实地研究周的研究人员将使用创新的研究技术来检查定量木材解剖（检查树木年轮中的单个生长细胞）以及稳定的同位素，以梳理气候、火灾和昆虫爆发与森林死亡率之间的关系。这些研究活动有助于参与者更好地了解这些森林的自然趋势，以便能够更准确地预测这些森林的未来条件，并能够实施更有效的森林管理战略。除了这些学习经验之外，实地周还为学生和专业人员提供了交流机会，并将树木年代学记录的好处扩大到森林管理者。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。

The North American Dendroecological Fieldweek (NADEF), is an annual ten-day field-based activity that teaches the tools of dendrochronology, provides networking opportunities for students and professionals, and expands the benefits of dendrochronological records to forest managers. Support for NADEF will catalyze new activities focusing on understanding the mechanisms behind the increases in global forest mortality, which has become more widespread than has been documented in preceding centuries. Understanding the mechanisms behind this forest mortality is critical for the development of intelligent, timely, and science-driven management responses to these mortality events. The field weeks will provide professional development for approximately 120 participants over a three-year period while educating participants about management information needed to sustain these forests. The field week will continue its strong record for broadening gender and ethnic diversity among scholars in dendrochronology. Opportunities for undergraduate scholarships will be provided to students from underrepresented groups, and graduate research fellowships will help educate and train students in professional presentation of the findings from the field weeks.NADEF has a 25-year history of bringing together a diverse group of scholars to learn cutting-edge dendrochronology science for the continuous improvement of research in the forestry sciences and the better management of forest resources. For this series of field weeks, participants will engage in five research projects that will focus on completing a fire history, insect-outbreak reconstructions, climate reconstructions, analyses of stand-age structure across an elevational gradient, and sclerochronology, which is the examination of annual rings in bony structures such as those found in clams and the ear bones of fish. Field week researchers will use innovative research techniques to examine quantitative wood anatomy (the examination of individual cells of growth in the tree rings) along with stable isotopes to tease apart relationships among climate, fire, and insect outbreaks on forest mortality. These research activities help participants to better understand the direction that these forests are naturally trending so that future conditions for these forests can be predicted more accurately and more effective forest management strategies can be implemented. Beyond these learning experiences, the field weeks provide networking opportunities for students and professionals and expand the benefits of dendrochronological records to forest managers.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.