Winter carbon losses in wetland ecosystem under current and future climates

高纬度寒冷地区，包括北极和加拿大北部地区，变暖的速度是地球其他地区的两倍多，最大的变暖发生在冬季。鉴于二氧化碳(CO2)排放的一个主要过程--微生物呼吸--即使在**零度以下的气温下也会随着变暖而增加，冬季是碳循环的关键时期。因此，随着气候变暖，非生长季(NGS；秋季、冬季、春季)的二氧化碳排放量预计将增加。然而，对寒冷地区生态系统当前NGS二氧化碳排放量的估计存在很大的不确定性。加拿大的温带到亚北极湿地和永久冻土泥炭地拥有大量的碳储存，在未来气候变暖的情况下，这些碳很容易流失。因此，了解在NGS期间控制温室气体排放的过程的因素，对于预测这些脆弱的**碳储存的命运和制定气候适应和缓解战略至关重要。专注于这些关键的**生态系统，我们汇集了来自多个学科的加拿大领导人以及联邦**政府科学家和政策制定者**，以确定NGS碳循环的驱动因素，开发**基于过程的环境模型，并估计二氧化碳排放量。为此，我们将解决关于NGS排放的知识差距，以提供数据和工具，评估冬季变暖缓解在**控制泛加拿大湿地生态系统碳损失方面的影响。通过综合历史数据、实验室实验和建模，拟议的研究将侧重于1)确定推动微生物NGS碳循环的**水文和气候因素；以及2)将所获得的信息和**数据整合到描述控制NGS排放的基本过程的模型中，以便纳入**加拿大林业部门碳预算模型(CBM-CFS)。这将提高我们跟踪**和预测寒冷地区湿地生态系统中的碳通量的能力，并提出改进的、基于证据的**建议，以估计冬季碳损失和评估缓解策略。

High latitude cold regions, including Arctic and northern areas of Canada, are warming more than twice as fast**as the rest of the planet, with the greatest warming occurring during the winter. Given that a major process**responsible for carbon dioxide (CO2) emissions, microbial respiration, increases with warming even at**sub-zero temperatures, winter is a critical period for carbon cycling. Consequently, CO2 emissions during the**non-growing season (NGS; fall, winter, spring) are expected to increase as the climate warms. However, there**is large uncertainty in estimates of current NGS CO2 emissions from cold region ecosystems. Canada's**temperate to subarctic wetlands and permafrost peatlands hold large stores of carbon which are susceptible to**loss under future climate warming scenarios. Therefore, understanding the factors which regulate the processes**controlling greenhouse gas emissions during the NGS is critical for predicting the fate of these vulnerable**carbon stocks and for creating climate adaptation and mitigation strategies. With a focus on these critical**ecosystems, we bring together Canadian leaders from multiple disciplines from across universities with federal**government scientists and policy makers to determine the drivers of NGS carbon cycling, develop**process-based environmental models, and estimate CO2 emissions. In doing so, we will address the knowledge**gaps on NGS emissions to provide data and tools to evaluate the impact of winter warming mitigation in**controlling carbon losses from pan-Canadian wetland ecosystems. Through a combination of historical data**synthesis, laboratory experiments and modelling, the proposed research will focus on 1) determining the**hydrological and climatic factors driving microbial NGS carbon cycling; and 2) integrating the information and**data gained into models describing the underlying processes controlling NGS emissions for incorporation into**the Carbon Budget Model of the Canadian Forest Sector (CBM-CFS). This will advance our ability to track**and predict carbon fluxes in cold regions wetland ecosystems and make improved, evidence-based**recommendations to estimate winter carbon losses and evaluate mitigation strategies.