Collaborative Research: Biogenic Volatile Organic Compounds and their Impacts in a Changing Temperate Forest

该项目是一项合作努力，涉及来自四个机构的研究人员，他们在测量和解释生物挥发性有机碳（BVOC）化合物和相关反应产物方面具有互补的专业知识。 该项目被设想为旨在检验以下假设的长期研究倡议的一部分：“BVOC排放对气候的影响取决于BVOC的结构;异戊二烯可以影响臭氧的产生，而萜烯在氮固存和气溶胶产生方面更有效;在森林中以萜烯为主的变化将导致更多的碳固存，其他因素保持不变。“在第一年，主要研究人员将在实验室建造和测试一个自动测量系统，包括一个采样装置、一个二维气相色谱仪和一个校准系统，以每小时量化特定BVOCs和反应产物的环境混合比。取样装置将浓缩BVOCs和反应产物，并转移到配有两个二级柱的GC中。 一个通道将进料火焰离子化检测器（FID）以定量BVOC，另一个通道进料电子捕获检测器（ECD）以定量氧化产物（包括硝酸盐和羟基硝酸盐）。通用校准源将包括一个温控浴槽，其中包含多个化合物特定扩散管和相关管道。在第二年，PI将在密歇根大学生物站（UMBS）的氧化剂研究计划：光化学，排放，运输（PROPHET）站点部署并持续运行这种新型半自动测量系统，为期4周。 现场部署的目标是测试仪器在可靠地定量一系列重烷烃、烯烃、芳烃、异戊二烯、单萜、倍半萜、醛和酮以及醇方面的性能，和有机硝酸盐在环境空气中的林冠层内和上方。发展的半-BVOCs及其反应产物的自主测量系统将提高森林动态、氧化过程气溶胶的产生、氮和碳的固存以及相关的气候反馈。该项目的成果还将扩大PROPHET数据档案，该档案一直是对森林-大气相互作用进行更广泛调查的宝贵社区资源。研究生和本科生将直接参与构建和现场测试仪器。研究结果将通过科学文献中的文章传播，并纳入基于探究的教学网络探索，以帮助高中生了解全球气候变化背景下的生物圈-大气研究。这个网络探索将成为UMBS类似教育资源库的一部分。

This project is a collaborative effort involving investigators from four institutions with complimentary expertise in measuring and interpreting biogenic volatile organic carbon (BVOC) compounds and associated reaction products. The project is envisioned as part of a longer-term research initiative designed to test the following hypothesis: "The impact of BVOC emissions on climate depends on the structures of the BVOC; while isoprene can impact ozone production, terpenes are more effective at nitrogen sequestration and aerosol production; the change to terpene-dominance in forests will lead to more carbon sequestration, other factors remaining the same." During year 1, the principal investigators (PIs) will construct and test in the laboratory an automated measurement system consisting of a sampling apparatus, a two-dimensional gas chromatograph (GCxGC), and a calibration system to quantify ambient mixing ratios of speciated BVOCs and reaction products hourly. The sampling apparatus will concentrate BVOCs and reaction products and transfer to a GC fitted with two secondary columns. One channel will feed a flame ionization detector (FID) to quantify BVOCs and the other an electron capture detector (ECD) to quantify oxidation products (including nitrates and hydroxynitrate). The general utility calibration source will include a temperature-controlled bath containing multiple compound-specific diffusion tubes and associated plumbing. During year 2, the PIs will deploy and continuously operate this novel semi-autonomous measurement system at the Program for Research on Oxidants: PHotochemistry, Emissions, & Transport (PROPHET) site at the University of Michigan Biological Station (UMBS) over a 4-week period during the growing season. The goal of the field deployment will be to test the instrument's performance in reliably quantifying a broad suite of heavy alkanes, alkenes, aromatics, isoprene, montoterpenes, sesquiterpenes, aldehydes and ketones, and alcohols, and organic nitrates in ambient air within and above the forest canopy.The development of a semi-autonomous measurement system for BVOCs and reaction products will enhance observational resolution for investigations of interactions among forest dynamics, oxidation processes, aerosol production, nitrogen and carbon sequestration, and associated feedbacks on climate. Results from the project will also extend the PROPHET data archive, which has been a valuable community resource for broader investigations of forest-atmosphere interactions. Graduate and undergraduate students will participate directly in constructing and field testing the instrument. Results will be disseminated through articles in the scientific literature and also incorporated into an inquiry-based instructional webquest to help high school students understand biosphere-atmosphere research in the context of global climate change. This webquest would become part of a library of similar educational resources at UMBS.