An Experienal Study of Exchange Characteristics ofMass Exchange in a Plant Canopy Layer
植物冠层内物质交换特征的实验研究

Using determined gradient data of both turbulence and SO2 flux,characteristics of mass exchange in a plant canopy layer(CL) are studied in detail.The following results are found:the absorption of mass due to plant biological processes is very considerable.Mass flux in the CL decreases with the increase of depth of the CL.Deposition velocity in the upper CL is greater than that in the lower CL for tall plant.There is considerable diurnal variation of deposition velocity in the CL, biological absorption of mass in the CL is directly related to total magnitude of the solar radiation;deposition velocity in CL is direct correlated with V* and V;Vg for forest is less than that for wheat;Vg in Chongqing forest and wheat is forecasted well by the new deposition velocity pattern.