Measurements of oxygenated volatile organic compounds emitted from tropical plants

在温室中测量热带植物排放的挥发性有机化合物（VOCs），其中代表性物种从东南亚的低地热带森林生长，以及在马来西亚Pasoh的热带雨林。48种挥发性有机物，包括25种含氧有机物（半挥发性醛类如壬醛、癸醛、乙酸3-己烯酯、6-甲基-5-庚烯-2-酮、3-甲基呋喃、2-甲基呋喃等）。在所调查的30种热带植物的排放气体中检测到。结果表明，半挥发性醛类的释放速率在白天增加。叶片表面蜡质的臭氧分解以及叶片的直接排放是醛类物质释放的可能途径。在本研究中，还发现一些常见的热带植物（某些类型的蕨类植物和龙脑香科）排放大量的氯甲烷。排放率为每小时每克干叶0.1至3.7微克，表明热带植物可以解释大部分甲基氯来源的缺失。结果表明，带有附生地衣的龙脑香叶片能显著降低氯甲烷的排放。

Volatile organic compounds (VOCs) emitted from tropical plants were measured in a greenhouse where representative species from lowland tropical forests of South East Asia grow, as well as in a tropical rainforest at Pasoh, Malaysia. Forty eight kinds of VOCs including 25 oxygenated VOCs (semi-volatile aldehydes such as nonanal and decanal, 3-hexenyl acetate, 6-methyl-5-hepten-2-on, 3-methyl furan, 2-methyl furan etc.) were detected in the emission gases from the thirty species of tropical plants investigated. It was found that semi-volatile aldehydes emission rates were increased during the daytime. Ozonolysis of leaf-wax at the surface, as well as the direct emission from leaves, were possible pathways for the aldehydes emissions. Large emission of methyl chloride from some common tropical plants (certain types of ferns and Dipterocarpaceae) was also found in this study. The emission rate ranged from 0.1 to 3.7 ug per gram dry leaf per hour, suggesting that tropical plants could explain a large portion of missing methyl chloride source. It was found that dipterocarp leaves with epiphytic lichens greatly reduced emission of methyl chloride.