Radiation budget and soil heat flux at forest floor in warm-temperate mixed forest

Seasonal change in the radiation budget of a forest floor was measured in a mixed forest located in Kyoto, Japan. The basal area at breast height in the survey forest was about 15.82m²ha^-1 for evergreen trees and 12.46m²ha^-1 for deciduous trees, respectively. The sky view factor was 16% and 22% at the survey site in the foliate and defoliate seasons, respectively. This small difference influenced the seasonal course of radiation budget of a forest floor, Namely, that net long wave radiation changed rapidly in leaving and falling days and that the maximum rate of net short wave radiation was measured in April. Distinctive characteristics of the radiation budget were recognized in the seasonal change that available radiation rates in daytime and night were almost equal in September and October. (author)