STEMFLOW, THROUGHFALL AND RAINWATER INTERCEPTION OF EIGHT INDONESIAN TREE SPECIES

Tree architecture affects how rainwater is partitioned into canopy interception, throughfall and stemflow. The canopy shape and bark/leaf surface morphology affects the plants’ ability to intercept and redistribute the rainwater. Hence, the tree structure plays a key role in soil and water conservation, especially in erosion runoff. This research was conducted to predict the most suitable tree species for soil and water conservation, and recorded 32 rainfall events during the rainy season in January 2014-March 2015 in Purwodadi-LIPI, Indonesia. The stemflow, throughfall, individual tree architectural characteristics, and leaf morphology were measured for eight selected local tree species namely: Sterculia cordata, Aleurites moluccanus, Buchanania arborescens, Calophyllum inophyllum, Dysoxylum gaudichaudianum, Peltophorum pterocarpum, Alstonia scholaris, and Pometia pinnata. The species which held the greatest amount of interception was Aleurites moluccanus at 68.1% of rainfall. Special characteristics of the leaves (like fine hairs), globose stem and long, grooved bark, probably resulted in an  increased relative interception of the rain water that was higher than those of other trees. The throughfall and stemflow for each species were closely related to rainfall amount but not related to rainfall intensity.