Collaborative Research: Predicting Micro to Macro-scale Hot-spot and Hot-moment dynamics in Arctic Tundra Ecosystems

北极的快速气候变暖正在融化冻土，也被称为永冻土，这不仅重塑了地表地形，还增加了向大气中排放的温室气体。由于北极景观变化的速度，以及冻土中大量的碳库，提高对植物和微生物之间的关键相互作用及其对温室气体排放的影响的知识，对于预测北极土壤融化将如何促进全球气候变化至关重要。该项目的总体目标是确定驱动热点和热点时刻碳动态的微观机制，以提高对宏观尺度碳平衡的预测。我们假设，退化的营养丰富的永久冻土的时空分布变化已经并将从根本上改变北部冻土带生态系统的结构和功能，从微生物到景观。这个多尺度的跨学科项目将改变我们对控制多年冻土生态系统过去和预测的碳循环动态的基本植物-土壤-微生物相互作用的知识，同时促进对永久冻土融化在空间(即从地块到景观)和时间(即从季节性到年代际)的关键生物地球化学后果的了解。将结合低精度和高精度的地面和航空通量观测来描述热点和热点时刻碳动力学的时空机制，以确定二氧化碳(CO2)和甲烷(CH4)热点的位置并评估其大小。地面和遥感观测将决定对观测到的热点和通量的空间分布的控制，对植物、微生物和地形的时空分析，加上永久冻土退化的时间安排，将推断热时刻的存在，而孵化实验将阐明跨越阿拉斯加北部北极海岸平原地点的热时刻的驱动机制。因此，拟议的研究将为下一代机械和基于过程的模式提供基础，以代表新北极的新干扰制度。阿拉斯加本土高中生参与北极扰动生态的合作网络不断扩大，将对这些研究工作表示赞赏。学生们将使用无人机测量他们的环境，并在校园内和更广泛的科学界分享结果。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Rapid climate warming in the Arctic is thawing frozen soils, also known as permafrost, which is not only reshaping surface topography but also increasing the release of greenhouse gases to the atmosphere. Due to the speed in which Arctic landscapes are changing, and the massive carbon pools locked in permafrost, improving knowledge of the key interactions between plants and micro-organisms and their impacts on greenhouse gas release is essential for predicting how thawing Arctic soils will contribute to global climate change.The overarching objective of this project is to determine the micro-scale mechanisms driving hot-spot and hot-moment carbon dynamics, for improving predictions of macro-scale carbon balance. We hypothesize that the altered spatiotemporal distribution of degrading nutrient-rich permafrost has and will fundamentally alter the structure and function of northern tundra ecosystems, from microbes to landscapes. This multi-scale interdisciplinary project will transform our knowledge of fundamental plant-soil-microbial interactions that govern past and projected carbon cycle dynamics in permafrost ecosystems, while advancing knowledge of the key biogeochemical consequences of permafrost thaw over space (i.e., plot to landscape) and time (i.e., seasonal to decadal). The spatiotemporal mechanisms of hot-spots and hot-moment carbon dynamics will be characterized using a combination of low and high-precision ground and airborne flux observations to determine the location and assess the magnitude of carbon dioxide (CO2) and methane (CH4) hot-spots. Ground and remote sensing observations will determine the controls on the observed spatial distribution of hot-spots and fluxes, space-for-time analyses of plants, microbes, and landforms, coupled with the timing of permafrost degradation will infer the existence of hot-moments, while incubation experiments will illuminate the mechanisms driving hot-moments across sites across the Arctic Coastal Plain of northern Alaska. The proposed research will therefore provide the foundation for next-generation mechanistic and process-based models to represent novel disturbance regimes in the new Arctic. These research efforts will be complimented by a growing collaborative network of Alaskan native high-school student involvement in Arctic disturbance ecology. Students will use drones to measure their environment and share results across campuses and with the broader scientific community.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.