LTREB Renewal: The reorganization and resynchronization of biogeochemical cycles after an unprecedented tundra fire

在北极苔原，火灾在历史上是罕见的，但预计在未来更温暖的世界中，火灾的严重性和频率将增加。 该生物群落中火灾的罕见性使得测量，理解和预测火灾对重要生态系统服务（如物种多样性和生态系统碳循环）的后果具有挑战性。此外，火灾的影响持续很长时间-数年至数十年-改变了对长期生态系统恢复至关重要的关键生物地球化学循环。由于火灾的严重程度可以显着降低土壤养分的可用性，据推测，生态系统的恢复是依赖于燃烧的严重程度和火灾后的土壤资源。该项目是一个为期十年的项目的继续，该项目研究火灾对阿拉斯加苔原生态系统陆地碳循环的影响。该研究结合了长期生态观察，营养添加实验和生态系统模型的改进。正在为本科生和研究生提供培训和劳动力相关技能。将出版一本面向公众的儿童读物，以及一段YouTube视频。本研究将获取并综合2007年阿拉斯加北坡前所未有的阿纳克图武克河大火的生态系统功能的多年代记录（2008-2026）。涡协方差通量和生物量收获将测量的时间变化，生态系统的碳通量和股票在整个燃烧严重度梯度（严重，中度，和未燃烧的苔原），而养分施肥实验在严重和未燃烧的苔原网站将确定的作用，养分供应的生态系统恢复的速度。 这些记录将为耦合地球化学模型（即多元素限制[MEL]模型）提供信息，以改善火灾对北极生态系统碳循环的长期影响的预测。MEL模型的开发将为科学家、土地管理者和政策制定者提供一个强有力的工具，以量化这一快速变化地区未来火灾的影响。该奖项反映了NSF的法定使命，并被认为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来支持。

Fire has been historically rare in the Arctic tundra, but is projected to increase in severity and frequency in a future warmer world. The rarity of fires in this biome has made it challenging to measure, understand, and predict the consequences of fire on important ecosystem services such as species diversity and ecosystem carbon cycling. Furthermore, the impacts of fire last a long time-- years to decades-- by altering critical biogeochemical cycles that are important for long term ecosystem recovery. Since fire severity can dramatically reduce soil nutrient availability, it is hypothesized that ecosystem recovery is dependent on both burn severity and post-fire soil resources. This project continues a ten-year project studying the effects of fire on terrestrial carbon cycling in Alaskan tundra ecosystems. The research combines long-term ecological observations, a nutrient addition experiment, and improvement of an ecosystem model. Training and workforce relevant skills for both undergraduate students and graduate students are being provided. A children’s book will be published to reach the general public, as well as a YouTube video. A large amount of data about ecosystem processes is being contributed to public databases.This research will acquire and synthesize a multi-decadal record (2008-2026) of ecosystem function from the unprecedented 2007 Anaktuvuk River fire on the North Slope of Alaska. Eddy covariance fluxes and biomass harvests will measure temporal changes in ecosystem carbon fluxes and stocks across a burn severity gradient (Severe-, Moderate-, and Un-burned tundra), while nutrient fertilization experiments at the Severe- and Un-burned tundra sites will determine the role of nutrient availability on the rate of ecosystem recovery. These records will inform a coupled biogeochemical model (i.e. the Multiple Element Limitation [MEL] model) to improve predictions of the long term impacts of fire on Arctic ecosystem carbon cycling. The development of the MEL model will provide a powerful tool for scientists, land managers, and policy makers to quantify the future impacts of fire in this rapidly-changing region.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.