Throughfall, stemflow and interception loss of artificial tropical forest

An interception study of man-made forest was carried out in Bukit Lagong Reserved Forest. Out of 18 rainfall event recorded, all 18 events produce throughfall but only 15 events with measured stemflow. Two plots of 20m × 20m each were established to measure the distribution of interception (gross rainfall, P_g, throughfall, T_f and stemflow, S_f) and identify the percentage of forest canopy cover over the plotted area. Hemispherical photography method using fisheye lens was applied to capture canopy cover image over the plots. The forest plots were occupied with mixed dipterocarp trees consist of two canopy levels with 90% to 98% of canopy cover. The range of interception loss for this study is 1% to 73% with average of 30% of total gross rainfall. The relationship between interception loss and gross rainfall show a moderate correlation with r² values of 0.3002. The canopy cover does impose significant effect to the loss of rainfall interception. From point-correlation, the interception loss (%) is increase proportionally to the canopy cover (%) with r² values of 0.4559.