Biogenic Sources of Oxygenated Hydrocarbons in the Troposphere

挥发性有机化合物（VOCs）排放的影响 植被对大气化学的影响正在增加 审查，特别是因为他们发挥核心作用， 光化学烟雾形成。 过去的调查集中在 挥发性有机化合物的碳氢化合物成分，但最近大量 氧化烃（OHC），如甲醇和丙酮， 在乡村森林的空气中发现了这种物质， 它们的起源和在对流层化学中的作用。 初步测量表明，甲醇可以通过 叶高速率，类似于异戊二烯排放， 针叶树的芽会释放出大量的丙酮 这表明植被是挥发性物质的重要来源， OHC的。 该提案涉及几个关键问题。1)多少 甲醇和丙酮是由不同种类的植物排放的？（二） 有哪些不同的植物部位（例如，芽、叶、树皮等）发射 甲醇和丙酮3)环境，物候，季节， 和植物胁迫影响甲醇和丙酮的排放？ 的 环境和压力的影响将在 受控实验室实验。 OHC的通量， 不同的植物家庭将被评估为农村的一部分， 南方环境中的氧化剂（ROSE II）研究 东南森林（1992年夏季），并从实地调查， 博尔德区 将使用芽、叶、分支、 用气相色谱法进行OHC分析。 这项工作将提供第一个全面的概述植物 甲醇和丙酮排放，这将是有用的， 对流层化学的大气模拟，特别是 农村地区，并将提供自然资源的估计， 在含甲醇燃料出现之前， 线

The impacts of volatile organic compounds (VOCs emitted by vegetation on atmospheric chemistry are under increasing scrutiny, especially since they play a central role in photochemical smog formation. Past investigations have focused on hydrocarbon components of VOC's, but recently large quantities of oxygenated hydrocarbons (OHC's), such as methanol and acetone, have been found in the air of rural forests, leading to questions about their origins and roles in tropospheric chemistry. Preliminary measurements indicate that methanol can be emitted by leaves at high rates, similar to that for isoprene emission, and that conifer buds emit substantial quantities of acetone, suggesting that vegetation is a significant source of volatile OHC's. The proposal addresses several key questions. 1) How much methanol and acetone are emitted by various species of plants? 2) What different plant parts (e.g., buds, leaves, bark, etc.) emit methanol and acetone? 3) How do environment, phenology, season, and plant stress influence methanol and acetone emissions? The effects of environment and stresses will be examined in controlled laboratory experiments. Fluxes of OHC's from different plant families will be assessed as part of the Rural Oxidants in a Southern Environment (ROSE II) study in a southeastern forest (summer 1992), and from field surveys in the boulder area. Fluxes will be measured using bud, leaf, branch, and stem enclosures with OHC analysis by gas chromatography. This work will provide the first comprehensive overview of plant methanol and acetone emissions, which will be useful in atmospheric modeling of tropospheric chemistry, particularly of rural areas, and will provide estimation of natural sources of atmospheric methanol before methanol-containing fuels come on line.