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温室气体在驱动气候变化的净气候强迫中占30%左右：一氧化二氮（N2 O）和甲烷（CH 4）尤为重要，陆地生态系统既是这些气体的重要汇，也是其重要源。最近从政策角度强调了非二氧化碳温室气体，因为排放是无意的，往往代表着经济损失，但需要为政策和管理实践提供信息，这方面存在重要的科学空白。直到最近，人们还认为土壤是N2 O和CH 4交换的主要场所;然而，最近的研究发现，这些气体的大量交换是通过植物，特别是树木进行的。需要更好地了解这些通量，以制定减少非二氧化碳温室气体来源并增强其汇的管理实践。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CO2和水蒸气以及溶解在木质部流中的微量气体;然而，很少有测量将CO2通量与其他温室气体通量联系起来。我们的研究小组最近记录了安大略森林管理中树叶对CH 4的大量吸收，但了解其机制（例如，CH 4氧化是由于树叶中的甲烷氧化细菌？）和控制（例如，这是如何随着光线和温度的变化而变化的？）对于这些过程，需要一个气体交换系统，将光合作用测量与痕量气体通量结合起来。除了CH 4通量，N2 O通量介导的植物可能是重要的管理系统与高N输入，如城市森林和绿色屋顶。 光谱气体分析的最新创新允许快速准确地测量N2 O和CH 4浓度。我们请求提供资金，以建立一个独一无二的系统，该系统将光合作用测量与快速N2 O和现有的现场便携式CH 4分析仪相结合，从而能够研究叶、茎和其他植物器官的所有三种温室气体（N2 O、CH 4和CO2）的通量，并测量土壤和整个系统的通量。这一系统允许的测量将有助于更好地了解受管理的生态系统中涉及温室气体交换的机制，并将有助于制定管理办法，最终目标是通过受管理的森林和城市生活基础设施加强气候缓解。