Measuring soil greenhouse gas flux to predict arctic carbon flow and promote sustainable agriculture in the era of climate change.

气候变化和人类活动正在改变土壤生态系统中的碳流，但我们对土壤温室气体（GHG）排放的微观和宏观驱动因素的理解仍然有限。不同环境或不同农业做法下土壤温室气体通量的原位测量是将地下代谢和微生物活动信息与其对全球温室气体收支和气候变化的影响联系起来的最佳工具之一。因此，我们需要一种便携式微量气体分析系统（LI-COR LI-7810），能够对关键温室气体（包括CO2和CH4）的土壤-大气通量进行灵敏、实时的量化。LI-7810将为加速nserc资助的L. Whyte、C. Kallenbach、J. Whalen、G. Clark和C. Madramootoo的研究项目提供至关重要的数据。怀特和卡伦巴赫将使用LI-7810从永久冻土、永久冻土解冻池、冰川消融土壤和其他北极栖息地收集温室气体通量测量数据。随着北极地区因气候变化而持续变暖，土壤微生物的活动可能会以不同的方式加速或减弱温室气体的释放。通过对土壤化学和微生物活动的分析来补充温室气体通量测量，这些项目将确定对北极温室气体排放的生物和非生物控制，并为预测未来的温室气体释放提供基线数据。在农业领域，Whalen和Madramootoo将使用LI-7810来确定不同肥料、土壤补剂和水管理措施对试验田土壤温室气体通量的影响。一些土壤补充物可以从有机废物中产生，从而有助于循环经济，克拉克将探索如何使用处理过的有机残留物作为土壤补充物来增加或减轻温室气体通量。这些项目对于改善农业生态系统管理以减少温室气体排放至关重要。最后，Kallenbach、Clark和Madramootoo将探讨间歇性洪水和冻融循环对农业温室气体排放的影响。气候变化使这些事件越来越普遍，了解这些事件如何影响地下微生物过程和土壤温室气体排放将促进管理实践的发展，有助于减轻洪水和冻融引起的温室气体释放。总的来说，我们从LI-7810中获得的数据将为加拿大和全世界的环境和农业科学和政策提供信息。我们预计每年约18 HQP将学会测量和解释不同生态系统水平上的温室气体通量，从而在微生物生态学、土壤科学、农业食品实践和废物管理方面形成新一代具有竞争力的HQP。这些HQP将准备向未来的雇主提供他们在研究、监管事务、现场应用、咨询和教学等领域的专业知识。如果仪器时间允许，我们也将从我们领域的其他实验室提供设备给HQP。

Climate change and human activity are altering carbon flows through soil ecosystems, but our understanding of the micro- and macro-scale drivers of soil greenhouse gas (GHG) emissions remains limited. In situ measurements of soil GHG flux in different environments or under different agricultural practices are one of the best tools for connecting information on belowground metabolism and microbial activity to their effect on global GHG budgets and climate change. We therefore require a portable trace gas analysis system (LI-COR LI-7810) capable of performing sensitive, real-time quantification of the soil-atmosphere flux of key GHGs, including CO2 and CH4. The LI-7810 will provide data that is crucial for accelerating the NSERC-funded research programs of L. Whyte, C. Kallenbach, J. Whalen, G. Clark, and C. Madramootoo. Whyte and Kallenbach will use the LI-7810 to collect GHG flux measurements from permafrost, permafrost thaw ponds, deglaciated soils, and other arctic habitats. As the arctic continues to warm due to climate change, the activity of soil microorganisms may accelerate or attenuate the release of GHGs in context-dependent ways. By complementing GHG flux measurements with analyses of soil chemistry and microbial activity, these projects will identify the biotic and abiotic controls on arctic GHG emissions and provide baseline data for predicting future GHG release.In the agricultural sector, Whalen and Madramootoo will use the LI-7810 to determine the effects of different fertilizers, soil supplements, and water management practices on soil GHG flux in experimental fields. Some soil supplements can be produced from organic waste, thus contributing to a circular economy, and Clark will explore how the use of processed organic residues as soil supplements increases or mitigates GHG flux. These projects are essential for improving agroecosystem management to reduce GHG emissions. Finally, Kallenbach, Clark, and Madramootoo will explore the effects of intermittent flooding and freeze/thaw cycles on agricultural GHG emissions. Climate change is making these events increasingly common, and an understanding of how these events affect belowground microbial processes and soil GHG emissions will facilitate the development of management practices that can help mitigate flood- and freeze/thaw-induced GHG release. Overall, the data we obtain from the LI-7810 will inform environmental and agricultural sciences and policies in Canada and throughout the world. We expect ~18 HQP/year will learn to measure and interpret GHG flux at various ecosystem levels, resulting in a new generation of competitive HQP in microbial ecology, soil science, agri-food practices, and waste management. These HQP will be poised to provide their expertise to future employers in areas including research, regulatory affairs, field applications, consulting, and teaching. If instrument time permits, we will also make the equipment available to HQP from other labs in our fields.