Elucidating soil carbon dynamics for climate change adaptation and mitigation tradeoff analysis at a landscape scale

提高农业生产的复原力并减少农业对气候变化的影响(即适应和缓解)的一个关键战略是采用有益的管理做法，增加土壤有机碳(SOC)的固存。然而，这一潜力的大小尚不清楚，最近的研究表明，温度上升导致的SOC损失可能比之前预期的要高。为了解决这种不确定性，需要在多个空间和时间尺度上处理一些问题。在田间尺度上，关于土壤有机碳与各种环境(如温度、降水)和管理因素(如耕作、土地利用变化)之间的动态关系的问题仍然存在。人们对影响SOC损失率的因素知之甚少，因为SOC可以恢复的速度或浓度收益将在多大程度上趋于平稳。在景观尺度上，还不清楚在给定BMP配置和土地利用变化的情况下，过程模型如何有效地预测SOC的长期变化，以及新的建模方法是否可以提高模拟的准确性。*我的研究计划的总体长期目标是制定战略，在最大限度地保持农业景观中的SOC的同时，最大限度地减少温室气体排放。我们的短期计划主要集中在了解控制SOC动态的机制，并改进过程模型以在景观尺度上测试假设。我们的方法需要利用地理信息系统、遥感和生态系统过程模型，将地块级别的分析扩展到景观，并随着时间的推移预测结果。我们五年研究计划的总体目标将解决以下问题：多年生植被BMP下SOC固存的速度、数量和持续时间是否能够在景观尺度上优化农业气候变化适应和缓解目标。*我的实验室五年研究计划有三个具体目标：*(1)量化BMP和土地利用变化的SOC封存和损失的速度、数量和持续时间；*(2.)阐明控制这些土地管理选项的SOC动态的机制；以及*(3.)给出预期的气候预测，在景观尺度上对BMP和土地利用变化选项进行参数化、验证和建模，以测试适应和缓解协同效应。*我的研究计划将增加对控制SOC固存机制的理解，以开发区域合适的模型，并帮助改善全球模型。这项研究将极大地加强加拿大和全球履行减缓气候变化承诺的努力，同时提高粮食生产能力。

A key strategy to improve the resiliency of agricultural production and also reduce the impact of agriculture on climate change (i.e. adaptation and mitigation) is the adoption of beneficial management practices (BMPs) that increase soil organic carbon (SOC) sequestration. However, the magnitude of this potential is unclear and recent work indicates SOC losses due to increasing temperatures may be higher than previously expected. To resolve this uncertainty a number of questions need to be addressed at multiple spatial and temporal scales. At the field scale, questions remain about the dynamics of SOC in relation to various environmental (e.g. temperature, precipitation) and management factors (e.g. tillage, land use change). Factors affecting rates of SOC loss are poorly understood as is the rate that SOC can be regained or at what concentration gains will level off. At the landscape scale it is unclear how effectively process-models predict long-term changes in SOC given BMP configurations and land-use change and whether new modeling approaches can improve the accuracy of simulations. ******The overarching long-term goal of my research program is to develop strategies that simultaneously maximize SOC retention within agricultural landscapes while minimizing GHG emissions. Our short-term program is focused primarily on understanding the mechanisms that control SOC dynamics and improving process models to test hypotheses at the landscape scale. Our approach entails scaling plot level analyses to the landscape and projecting outcomes over time using geographical information systems, remote sensing and ecosystem process models. The overarching objective of our five-year research program will address the following question: Does the rate, quantity and duration of SOC sequestration under perennial vegetation BMPs enable the optimization for both agricultural climate change adaptation and mitigation objectives at the landscape scale.******My lab's five-year research program has three specific objectives: ***(1.) Quantify the rate, amount and duration of SOC sequestration and losses for BMPs and land use change; ***(2.) Elucidate the mechanisms that control SOC dynamics for these land management options; and ***(3.) Parameterize, validate and model BMPs and land use change options at the landscape scale given expected climate projections to test for adaption and mitigation synergies.******My research program will increase the understanding of the mechanisms that control SOC sequestration to develop regionally appropriate models and help improve global ones. This research will greatly enhance Canadian and global efforts to meet commitments to mitigate climate change while at the same time improve the capacity to produce food.