The microclimate of dew and fog formation on canopy layer in the dry season in Xishuangbanna tropical rain forest
西双版纳热带雨林干季林冠层雾露形成的小气候特征研究

The microclimatic characteristics of the dew and fog formation on canopy layer within a tropical rain forest,dominated by \%Terminalia myriocarpa \% in Xishuangbanna were measured in the dry\|hot season.We investigated the net all\|wave radiation,air humidity,vertical air temperature gradient,and maximum and minimum air,ground surface and leaf surface temperatures.The results indicated that in the night,the dew and fog occured first on the top canopy layer,then the thickened fog penetrated into understory,and the formation time of the dew in the understory was 3~4 hours later than on the canopy layer.Before fog occuring the temperature was higher at 1.5m above the canopy than that on the leaf surface,and the temperature was lower after fog occuring.In the meantime the leaf surface temperature and air temperature were all rising after the fog occuring.The formation of the dew and fog not only condenses water vapour into the forest but also reduces the drop intensity of the temperature in the forest.This is of great ecological importance to the growth and development of the tropical rain forest.