CANOPY CROWN CLOSURE OF TRHREE FOREST TYPES AT NAMPROM BASIN, CHAIYAPHOOM PROVINCE PRICHA DHANMANONDA

Abstract

Percent canopy closure estimation was carried out in three forest types; dry evergreen forest, mixed deciduous forest and dry dipterocarp forest at Namprom Dam, Amphoe Khon-San, Chaiyaphoom Province during February 1979. In each stand, one sample plot 40 x 40 m² was laid out randomly.  The plot was then divided into 16 subplots (10 x 10 m.²) All trees 4.5 cm. or more in D.B.H. in each plot were mapped and their crown diameters were measured twice perpendicularly by a measuring tape. Three methods; planimeter method, weight-value-method and equal-area-segment method were applied for percent canopy closure calculation. The results showed that the percent canopy closure value decreases with the decreasing of the density of the trees, being maximum in dry evergreen forest and minimum in mixed deciduous forest. The three methods for percent canopy closure estimation are insignificant.