Author(s)

H. Suryatmojo, F. Masamitsu, K. Kosugi & T. Mizuyama

Abstract

Tropical forest management with selective logging and an intensive line planting system are expected to change the hydrological cycle. This study was conducted in a natural tropical rainforest of Central Kalimantan, Indonesia. Direct runoff and soil erosion were studied at three small catchment plots, a virgin forest catchment, a 1-year-old line plantation (2008 catchment) and a 10-year-old line plantation (1999 catchment). Direct runoff in the virgin forest catchment was 13.5% of precipitation. In the 1999 catchment and 2008 catchment, direct runoff was 31.1% and 19.7% of precipitation, respectively. The direct runoff rate in the 1999 catchment and 2008 catchment was 2.3 and 1.46 of the virgin forest catchment, respectively. Average soil erosion in the virgin forest catchment, the 1999 catchment and the 2008 catchment was 10.01 kg ha-1, 19.51 kg ha-1 and 25.83 kg ha-1, respectively. The 2008 catchment had the highest soil erosion rate at 2.58 of the virgin forest catchment. The 1999 catchment had a rate of 1.95 of the virgin forest catchment. The implementation of a forest management system should consider the impact of runoff and soil erosion. Controlling human erosional activities and finding ways to combine ecologically based vegetation structure design and soil erosion control techniques would be an effective way to control runoff and soil erosion. Keywords: selective logging, intensive line planting, virgin forest, logged over forest, direct runoff, soil erosion, vegetation structure, soil erosion control.

Keywords

selective logging, intensive line planting, virgin forest, logged over forest, direct runoff, soil erosion, vegetation structure, soil erosion control