REVEGETATION IN GAPS IN HILL EVERGREEN FOREST AT HUAY NAM DUNG WATERSHED STATION, CHANGWAT CHIANGMAI

Abstract

The process and rate of revegetation in gaps in hill evergreen forest were studied by comparing the species composition, tree density, frequency distribution of tree height, and relation between diameter at breast height and tree height among different aged stands. Stand ages were estimated by the ages of gap indicators. It took about 100 years for gaps to be filled by large fully-grown trees. Since the mean residence time of the forest canopy was 200 years, the trees that attain the forest canopy were expected to be canopy trees for 100 years on the average. According to the frequency distributions of height of live and dead trees in different aged stands, it was suggested that shorter trees were more susceptible to death than taller trees. The self- thinning in revegetation process in gaps approximately followed the 3/2 power law, though the power was larger (-1.30) than expected from the law.