Measurements of oxygenated volatile organic compounds emitted from tropical plants

从热带植物排放的挥发性有机化合物（VOCs）在东南亚低地热带森林的代表性物种生长的温室以及马来西亚帕索的热带雨林中进行了测量。在调查的30种热带植物的排放气体中检测到48种VOCs，其中含氧VOCs 25种（壬醛和癸醛、3-己烯乙酸酯、6-甲基-5-庚-2-on、3-甲基呋喃、2-甲基呋喃等半挥发性醛）。结果表明，半挥发性醛类物质的释放率在白天有所增加。叶蜡在地表的臭氧分解和叶蜡的直接排放可能是醛类化合物释放的途径。本研究还发现，一些常见的热带植物（某些类型的蕨类植物和龙心科植物）也会大量排放氯甲烷。排放率为每克干叶每小时0.1 ~ 3.7 ug，表明热带植物可以解释大部分缺失的氯甲烷来源。结果表明，带有附生地衣的龙脑果叶能显著减少氯甲烷的排放。

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.