Integrated system for photosynthesis and greenhouse gas flux measurements

光合作用和温室气体通量测量集成系统

• 批准号: RTI-2022-00511
• 负责人: Thomas, Sean
• 金额: $ 10.01万
• 依托单位: University of Toronto
• 依托单位国家: 加拿大
• 项目类别: Research Tools and Instruments
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=743000
• 关键词: Integrated; system; photosynthesis; greenhouse; gas

Non-CO2 greenhouse gases contribute ~30% to net climate forcing that drives climate change: nitrous oxide (N2O) and methane (CH4) are of particular importance, with terrestrial ecosystems acting as both important sinks and sources for these gases. Non-CO2 greenhouse gases have recently been emphasized from a policy perspective, as emissions are unintentional and often represent economic losses, but there are important science gaps needed to inform policy and management practices. Until recently it was assumed that soils were the primary sites of exchange of N2O and CH4; however, recent studies have discovered that substantial exchange of these gases that occurs through plants, in particular trees. A better understanding of these fluxes is needed to develop management practices that reduce sources and enhance sinks of non-CO2 greenhouse gases. Photosynthetic gas-exchange is the main physiological process by which plants exchange gases with the atmosphere - including CO2 and water vapor as well as trace gases dissolved in the xylem stream; however, there have been few measurements that link CO2 flux with the flux of other greenhouse gases. Our research group has recently documented substantial uptake of CH4 by tree foliage in managed forests in Ontario but understanding the mechanisms (e.g., is CH4 oxidation due to methanotrophic bacteria within tree leaves?) and controls (e.g., how does this vary with changes in light and temperature?) for these processes requires a gas-exchange system that integrates photosynthesis measurements with trace gas fluxes. In addition to CH4 flux, N2O flux mediated by plants is likely to be important in managed systems with high N inputs, such as urban forests and green roofs. Recent innovations in spectroscopic gas analysis allow for rapid and accurate measurements of both N2O and CH4 concentrations. We request funds for a one-of-a-kind system that integrates photosynthetic measurements with a rapid N2O and existing field-portable CH4 analyzer, allowing for studies of fluxes of all three greenhouse gases (N2O, CH4 and CO2) by leaves, stems, and other plant organs, as well as measurements of soil and whole-system fluxes. The measurements allowed by this system will permit a better understanding of mechanisms involved in greenhouse gas exchange in managed ecosystems and will facilitate development of management approaches with the ultimate goal of enhancing climate mitigation by managed forests and urban living infrastructure.

非CO2温室气体对驱动气候变化的净气候强迫的贡献约为30％：一氧化二氮（N2O）和甲烷（CH4）尤其重要，陆地生态系统既充当这些气体的重要水槽和来源。非CO2温室气体最近从政策的角度强调，因为排放是无意的，并且通常代表经济损失，但是为政策和管理实践提供了重要的科学差距。直到最近，假定土壤是N2O和CH4交换的主要地点。但是，最近的研究发现，通过植物，尤其是树木发生的这些气体的大量交换。需要更好地了解这些通量来开发减少源的管理实践并增强非CO2温室气体的水槽。光合气体交换是植物与大气交换气体的主要生理过程 - 包括二氧化碳和水蒸气以及溶解在木质部流中的痕量气体；但是，很少有测量将二氧化碳通量与其他温室气体的通量联系起来。我们的研究小组最近记录了安大略省托管森林中的树叶的大量吸收CH4，但是了解机制（例如，由于树叶中的甲烷营养细菌而引起的CH4氧化是否是否是氧化引起的？除了CH4通量外，植物介导的N2O通量在具有高N投入的托管系统中很重要，例如城市森林和绿色屋顶。 光谱气体分析的最新创新允许对N2O和CH4浓度的快速准确测量。我们要求为一种独一无二的系统提供资金，该系统将光合测量结果与快速的N2O和现有的可野外CH4分析仪集成，从而通过叶子，茎和其他植物器官以及土壤和全层的玻璃和全部效果进行测量。该系统允许的测量将使您可以更好地理解托管生态系统中温室气体交换的机制，并促进管理方法的发展，最终目标是通过托管森林和城市生活基础设施来增强气候缓解气候。