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动，但我们对土壤温室气体（GHG）排放的微观和宏观驱动因素的了解仍然有限。对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，我们需要一个便携式微量气体分析系统（LI-COR LI-7810），能够执行敏感的，实时量化的土壤-大气通量的关键温室气体，包括二氧化碳和甲烷。LI-7810将为加速NSERC资助的L。怀特角Kallenbach，J. Whalen，G. Clark和C.马德拉穆图。Whyte和Kallenbach将使用LI-7810收集来自永久冻土、永久冻土解冻池、冰川消退土壤和其他北极栖息地的温室气体通量测量结果。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少温室气体的释放。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，这些项目将确定生物和非生物对北极温室气体排放的控制，并为预测未来温室气体排放提供基线数据。在农业领域，Whalen和Madramootoo将使用LI-7810来确定不同肥料，土壤补充剂和水管理实践对实验田土壤温室气体通量的影响。一些土壤补充剂可以从有机废物中生产，从而促进循环经济，克拉克将探讨如何使用加工的有机残留物作为土壤补充剂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有助于制定管理措施，帮助减轻洪水和冻融引起的温室气体排放。 总体而言，我们从LI-7810获得的数据将为加拿大和世界各地的环境和农业科学及政策提供信息。我们预计每年约有18名HQP将学会测量和解释各种生态系统水平的温室气体通量，从而产生新一代在微生物生态学，土壤科学，农业食品实践和废物管理方面具有竞争力的HQP。这些HQP将准备好为未来的雇主提供他们的专业知识，包括研究，监管事务，现场应用，咨询和教学。如果仪器时间允许，我们也将从我们领域的其他实验室向HQP提供设备。

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.