Surface temperature distributions of tree crowns were examined with thermo-couples and infrared thermal images in June and October. As to the temperature difference between the crown surface and the ambient air, thermo-couples show partially higher surface temperatures in the daytime by 8 deg C at the highest. However the temperature difference obtained with the thermal images ranges form -2～0 deg C to -2～2 deg C. Since the thermal images directly show the radiative temperature distribution ,it is concluded the average radiative temperature on the tree crowns is almost as same as the ambient air temperature.
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