Carbon forms and fluxes in different land use systems

不同土地利用系统中的碳形态和通量

• 批准号: 249664-2013
• 负责人: Chang, Scott
• 金额: $ 2.91万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=634226
• 关键词: Carbon; forms; fluxes; different; land

To increase carbon (C) storage in the soil is important for mitigating the rapidly changing global climate. Afforestation of marginal agricultural land is considered a viable option for increasing soil C storage. However, the effects of land use change, afforestation in particular, on soil C dynamics are complex and poorly understood. In this research we will study four different land use systems, agricultural, grassland, forest plantation and native forests in the grassland-forest transition zone across western Canada. I will 1) investigate the effect of land use change on the emission of carbon dioxide (both by soil microbial organisms and by roots), methane and nitrous oxide, and their resulting global warming potential in each land use system; 2) evaluate the relative contribution of winter soil greenhouse gas (GHG) emissions to annual emissions and how that is affected by land use change, to help understand the total annual GHG fluxes of the different land use systems; 3) evaluate the effects of land use change on soil organic C forms, including low molecular weight organic acids, and C distribution in the subsoil; and 4) relate soil organic C form to soil C stability. This study will provide a full accounting of all three trace GHGs and on year-round rates of GHG emissions in different land use systems and will thus provide the much needed data for the calculation of national inventories of GHG emissions, as country-specific methodologies are needed to account for the impact of regional climate and land use on GHG emissions. Such data will help determine the emission factor for each land use system, allowing governments to adjust policies that will promote those land use systems that provide greater environmental services. The potential benefit of afforestation for climate change mitigation through increased C sequestration and C stability across the region will be studied. This study will thus provide novel information on the mechanisms of soil organic C stabilization and the mechanisms underlying the effects of land use change on GHG emissions. This research will eventually have implications for international treaty negotiations on climate change.

增加土壤中的碳(C)储量对于减缓快速变化的全球气候非常重要。边际农业用地造林被认为是增加土壤碳储量的可行选择。然而，土地利用变化，特别是造林，对土壤C动态的影响是复杂的，而且知之甚少。在这项研究中，我们将研究四种不同的土地利用系统，农业，草地，人工林和原生林在整个加拿大西部的草地-森林过渡带。我将1)调查土地利用变化对二氧化碳（土壤微生物和根系）、甲烷和一氧化二氮排放的影响，以及它们在每个土地利用系统中导致的全球变暖潜势；2)评估冬季土壤温室气体（GHG）排放对年排放的相对贡献及其受土地利用变化的影响，有助于了解不同土地利用系统的年温室气体总通量；3)评价土地利用变化对土壤有机碳形态（包括低分子量有机酸）和土壤碳分布的影响；4)土壤有机碳形态与土壤碳稳定性的关系。这项研究将全面计算所有三种微量温室气体以及不同土地利用系统的全年温室气体排放率，因此将为计算国家温室气体排放清单提供急需的数据，因为需要针对具体国家的方法来计算区域气候和土地利用对温室气体排放的影响。这些数据将有助于确定每个土地利用系统的排放系数，使政府能够调整政策，促进那些提供更多环境服务的土地利用系统。将研究造林通过增加整个区域的碳固存和碳稳定来减缓气候变化的潜在效益。该研究将为土壤有机碳稳定机制和土地利用变化对温室气体排放的影响机制提供新的信息。这项研究最终将对有关气候变化的国际条约谈判产生影响。