Fundamental Study on Control of Atmospheric Environment by Vegetation

1994年10-12月和1995年7-10月分别对植被和裸土进行了NO和NO2通量的微气象测量。试验地点为结缕草(Zoysia matrella Merr.)修剪到1厘米(平均叶面积为4，2)和未开垦的裸土，在大阪地方大学。用梯度法以及二氧化碳和水蒸气的通量测定了通量。用于计算的数据是在表面附近获得的，高度分别为2和8厘米。在实验室用化学发光分析仪测定了遮阳特氟龙袋中空气中NO和NO2的浓度。在许多情况下，NO通量的方向在草坪和裸露土壤上都是向上的。NO2通量的季节变化范围为7月份的-0.1~0.3mgN m^-1，10月份为-0.1~0.1mgN；h^&lt；-1，10月份为-0.1~0.1mgN；在草坪上方，通量与浓度之间存在负相关关系。草坪上NO2的沉积速率从7月份的约0.4 cm S降至12月份的0.1 cm S，这可能是气孔吸收NO2的季节变化所致。

NO and NO2 fluxes were measured micrometeorologically from Oct.to Dec.in 1994 above vegetation and from Jul.to Oct.in 1995 above vegetation and bare soil. The experimental sites were a lawn (Zoysia matrella Merr.) trimmed to 1 cm (average LAI 4,2) and uncultivated bare soil, in Osaka Prefecture University. The fluxes were determined using a gradient method, together with those of CO2 and water vapor. Data for calculation were obtained near the surfaces, at heights of 2 and 8 cm. NO and NO2 concentration of the air sampled in shaded Teflon bags was determined with a chemiluminescent analyzer in a laboratory. The direction of NO flux was upward above both the lawn and bare soil in many cases. The NO flux changed seasonally from -0.1 -0.3 mgN m^<-2>h^<-1> in Jul.to -0.1 -0.1 mgN m^<-2>h^<-1> in Oct. The direction of NO2 flux was almost downward above the lawn, while that above the bare soil was uncertain. Above the lawn, negative correlations between the flux and concentration were recognized. The NO2 deposition velocity on the lawn decreased from about 0.4cm s^<-1> in Jul.to 0.1 cm s^<-1> in Dec. This was probably caused by the seasonal change in NO2 absorption through stomata.