Carbon sequestration and greenhouse gas emissions in forests, wetlands and agricultural fields

森林、湿地和农田的碳封存和温室气体排放

• 批准号: RGPIN-2018-04277
• 负责人: Black, Thomas
• 金额: $ 3.72万
• 依托单位: University of British Columbia
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=712870
• 关键词: Carbon; sequestration; greenhouse; gas; emissions

The goal of my research is to better understand the processes and environmental controls that determine carbon (C) sequestration and greenhouse gas (GHG), namely CH4, CO2 and N2O, emissions in terrestrial ecosystems including forests, wetlands, and agricultural fields. This research aims to advance the development of technology and policy to better manage terrestrial ecosystems to increase C sequestration, minimize GHG emissions and the impacts of climate change, while maximizing productivity and water use efficiency. Net ecosystem production (NEP), evapotranspiration, and CH4 and N2O fluxes will be measured using the eddy-covariance (EC) technique. I will also use flux chamber measurements to quantify the temporal and spatial variability of, and effect of management on, soil GHG fluxes, and assess the reliability of scaling up chamber measurements to stand and field level. One of my aims will be to refine the partitioning of net ecosystem exchange of CO2 between ecosystem respiration (R) and gross ecosystem photosynthesis (GEP) by estimating light inhibition of leaf respiration during the daytime in a 29-yr-old West-Coast Douglas-fir stand. This will be accomplished by making EC measurements of 13CO2 and 12CO2, fluxes using a tunable diode laser - infrared gas analyzer system, with the isotopic flux ratios of NEE (NEE) and R (R) estimated from the ratios of the 13CO2 to 12CO2 fluxes during daytime and nighttime, respectively. In my research on mountain-pine-beetle impacted forest in the BC Interior, the focus will be to further improve the process-based forest growth model 3-PG that my PhD student Gesa Meyer has modified to include the effects of insect attack on a stand by treating understory and overstory growth separately, to include heterotrophic respiration (Rh) for determining NEP, and the extent of the increase in Rh due to increased coarse woody debris from dead trees. In an urban bog in the Lower Fraser Valley (LFV), the focus will be to understand the dynamics in the dominant processes controlling EC-measured CH4 and CO2 fluxes with the progression of restoration by rewetting, and to compare distinct sites characterized by peat-moss depth, soil wetness, and vegetation variations within the bog using mounted chambers to continue measurements during flooding events. The objective of my research on agricultural land is to improve our understanding of the processes controlling GHG emissions in major agricultural cropping systems in the LFV. This will involve studying the production, consumption, and transport of GHGs in the soil in situ using continuously sampled soil air at several depths in order to apply the gradient technique. These research projects will help understand and quantify the C balance of, and the GHG fluxes from, terrestrial ecosystems, and their potential in climate change mitigation, and also provide an excellent training environment for highly qualified personnel.

我的研究目标是更好地了解决定碳 (C) 封存和温室气体 (GHG)（即 CH4、CO2 和 N2O）以及陆地生态系统（包括森林、湿地和农田）排放的过程和环境控制。这项研究旨在推动技术和政策的发展，以更好地管理陆地生态系统，以增加碳固存，最大限度地减少温室气体排放和气候变化的影响，同时最大限度地提高生产力和水资源利用效率。生态系统净产量 (NEP)、蒸散量以及 CH4 和 N2O 通量将使用涡度协方差 (EC) 技术进行测量。我还将使用通量室测量来量化土壤温室气体通量的时间和空间变化以及管理对土壤温室气体通量的影响，并评估将通量室测量扩大到站和田间水平的可靠性。 我的目标之一是通过估计 29 年树龄的西海岸花旗松林白天叶片呼吸的光抑制，来完善生态系统呼吸 (R) 和总生态系统光合作用 (GEP) 之间二氧化碳净生态系统交换的划分。这将通过使用可调谐二极管激光-红外气体分析系统对 13CO2 和 12CO2 通量进行 EC 测量来实现，NEE (NEE) 和 R (R) 同位素通量比分别根据白天和夜间 13CO2 与 12CO2 通量的比率估算。在我对不列颠哥伦比亚省内陆山松甲虫影响森林的研究中，重点将是进一步改进基于过程的森林生长模型 3-PG，我的博士生 Gesa Meyer 已对该模型进行了修改，通过分别处理林下和林间生长来纳入昆虫侵袭对林分的影响，包括用于确定 NEP 的异养呼吸 (Rh)，以及由于死树粗木屑增加而导致的 Rh 增加程度。在弗雷泽河谷下游 (LFV) 的城市沼泽中，重点是了解控制 EC 测量的 CH4 和 CO2 通量的主要过程随着再润湿恢复的进展的动态，并使用安装的室在洪水事件期间继续测量，比较沼泽内泥炭苔深度、土壤湿度和植被变化的不同地点的特征。我对农业用地的研究目的是提高我们对 LFV 主要农业种植系统温室气体排放控制过程的理解。这将涉及使用梯度技术在多个深度连续采样土壤空气，研究土壤中温室气体的产生、消耗和运输。 这些研究项目将有助于了解和量化陆地生态系统的碳平衡和温室气体通量及其在减缓气候变化方面的潜力，并为高素质人员提供良好的培训环境。