西双版纳热带森林挥发性有机物的观测研究

2002年7月中旬利用异戊二烯通量测定系统对云南西双版纳热带森林异戊二烯的排放通量进行了连续测量,同时对光合有效辐射(PAR)、气温、湿度、风等参数进行了观测.结果表明,热带地区人工橡胶林区域湿季异戊二烯的排放有明显的日变化规律,中午前后为一天中的最大值,异戊二烯排放通量的日平均值在0.85～0.24mgC/(m²h)之间.对小时值和日平均值而言,异戊二烯的排放与PAR和气温的变化规律比较一致,但它对PAR比对气温更加敏感.不同的天气状况对异戊二烯的排放有非常明显的影响.橡胶林是一个单萜烯排放者,其单萜烯的排放速率明显依赖于PAR.橡胶林和热带雨林冠层上空异戊二烯和单萜烯的浓度也有明显的日变化规律,而且橡胶林区域的异戊二烯和单萜烯的浓度均明显高于热带雨林.

Observational studies on volatile organic compounds of the tropical forest in Xishuangbanna

Continuous measurement of isoprene emission flux of tropical forest in Xishuangbanna, Yunnan utilizingisoprene flux measurement system was conducted in July 2002; meanwhile, investigation of parameters such asphotosynthetically active radiation (PAR), air temperature, humidity and wind were conducted. The emission of isoprene in artificial rubber trees area in the wet season exhibited an obvious diurnal variation, with maximum value around noon, and daily averaged emission flux of 0.85~0.24mgC/(m2h). Hourly and daily average emission flux of isoprene wererelatively in accordance with the variation rule of PAR and air temperature, but being more sensitive with PAR than with air temperature. The emission of isoprene was very obviously influenced by different weather conditions. Rubber treeswere monoterpene emitters with emission rate dependence markedly on PAR. The concentrations of isoprene andmonoterpenes on the corolla of rubber trees and tropical rain forest also exhibited an obvious diurnal variation rule, and the concentrations of isoprene and monoterpenes in the rubber trees area were obviously higher than in the tropical rain forest.