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: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=570678
• 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.

增加土壤碳储量对减缓全球气候变化具有重要意义。边际农业用地的改造被认为是增加土壤碳储量的一个可行的选择。然而，土地利用变化，特别是造林，对土壤碳动态的影响是复杂的，知之甚少。在这项研究中，我们将研究四个不同的土地利用系统，农业，草地，森林种植园和原始森林在加拿大西部的草地森林过渡带。我将1）调查土地使用变化对二氧化碳排放的影响（土壤微生物和根系）、甲烷和一氧化二氮，以及它们在每个土地利用系统中产生的全球升温潜能值; 2）评估冬季土壤温室气体（GHG）排放量对年排放量的相对贡献，以及土地利用变化如何影响这一贡献;（3）评估土地利用变化对土壤有机碳形态（包括低分子量有机酸）和底土碳分布的影响;（4）将土壤有机碳形态与土壤碳稳定性联系起来。 这项研究将全面说明所有三种痕量温室气体和不同土地利用系统全年温室气体排放率，从而为计算国家温室气体排放清单提供急需的数据，因为需要有针对具体国家的方法来说明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使用系统的排放系数，使政府能够调整政策，促进提供更大环境服务的土地使用系统。将研究植树造林通过增加整个地区的碳固存和碳稳定性来缓解气候变化的潜在好处。因此，这项研究将提供新的信息，土壤有机碳稳定的机制和土地利用变化对温室气体排放的影响机制。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。