Analytical Heat Budget of a Natural <i>Machilus zuihoensis</i> Forest in Southern Taiwan

Abstract

This study reports observations of the microclimate in a natural Machilus forest. A series of observations for the net radiation; namely soil heat flux; leaf, air and earth temperatures; relative humidity and wind speed were all carried out from July 1998 to July 1999. All data was collected from an observation tower, which was located in the east of the experimental watershed of the National Pingtung University of Science and Technology, Taiwan (elevation=40-90m; latitude=22°39’N; longitude=120°36’E). The analytical heat budget of the Machilus forest could be used to determine the average proportion of soil heat flux, sensible heat, latent heat and canopy heat storage to net radiation, which were 5.2, 27.1, 42.6 and 25.1%, respectively. The regressive relationship between latent heat and net radiation showed a non-linear curve. Estimating evapotranspiration by the latent heat indicated that the mean value was 1.4±0.6 mm. The estimated canopy heat capacity was then between 0.2 and 0.41 cal･℃-1･m-3.