Application of silviculture treatment to Support Rehabilitation on Logged Over Area (LOA) of Tropical Rainforest, Central Kalimantan, Indonesia

Abstract

The tropical rainforest cover of Indonesia is the second largest in the word and represents 48% of SouthEast Asia's or 24% of the world's tropical forest cover. One of the main tree family in Indonesian's rainforest is dipterocarpaceae. This family is also the most important timber family. Indonesia's tropical rainforest has been deforested rapidly and the remaining forest is largely degraded. The enrichment of the degraded forest using native dipterocarp species is required. A plantation trial was established with two spacing types, two fertilizer dosages and five Shorea spp tree types as treatment. The highest and lowest survival rate at 6.5 years old were 86.7% for Shorea johorensis and 55.5% for S. virescent, respectively. The result of statistical analysis using ANOVA at 6.5 years old showed significant effects of treatments; (1) interactive effect of spacing x dosage (F=18.49,p<0.0056) on diameter growth, (2) interactive effect of spacing x dosage (F=7.58, p<0.033) on height growth and (3) species effect (F=3.19, p<0.021) on height growth. While the other treatments were not significant at a significance level of 0.05 for either diameter or height growth. S. leprosula exhibited the highest diameter and height growth with MADI of 2.2 cm. year-1 and MAHI of 1.32 m. year-1 at 6.5 years. Almost equivalent growth was recorded by S. Johorensis and S. parvifolia. Those species known as fast growing species with high survival rate were recommended as the species for rehabilitation.