Host: The Japanese Forestry Society
INTRODUCTION Kayu putih oil is one of non-wood forest product (NWFP) extracted from fresh leaves and twigs of kayu putih (Melaleuca leucadendron LINN white tea tree, Myrtaceae) tree through distillation process. In Java, kayu putih has been previously planted in order to rehabilitate degraded and infertile areas, and PT Perhutani, a forest enterprise, has been producing kayu putih oil since 4 decades ago. In some places, farmers surrounding the forest area participate in establishment of the plantation and cultivate crops between the trees in tangya or tumpangsari system. The plantation faces a crucial problem related to annual biomass removal from the tree due to the oil extraction. The research aims to compare plantation productivity and sustainability between different locations in Java, and to propose a basic knowledge for improving management practice of this NWFP.SITE, MATERIAL AND METHODS In Java, kayu putih plantation is managed by PT Perhutani. Main stem of the trees are cut at 1.1 m height in the 4th year after the transplanting. Coppicing and the leaf-twig harvest is repeated at one-year intervals. Kayu putih oil is extracted from collected leaves and twigs at oil factory in the plantation. In this research, 3 sites were selected; i.e. Ponorogo (site P) in East Java, Gundih (site G) in Central Java and Indramayu (site I) in West Java. The research was done within October 2000 to September 2002.In each site, plantation of various stand ages were selected and square plots of 20 m x 20 m were set. The trees are planted in 3 m x 1 m spacing (in P and I) and 2 m x 1 m (in G). D0 (diameter at the bottom of the tree) and number of tree per plot were measured and counted. In every plot, 10 sample trees were harvested following to ordinal commercial harvesting method and weighed individually. A sub-sample of leaf-twig and branch was taken for dry weight measurement in laboratory. Kayu putih oil was extracted from 5 kg of leaf-twig sub-samples per plot in a laboratory by water/steam distillation soon after harvesting. The trend of productivity in relation to stand age was estimated by using regression analysis. Plantation and oil production records collected by the enterprise were also used for the study. RESULT AND DISCUSSIONS In all sites, productivity increased with stand age to a maximum amount at about 20 to 30 years old. After that, there were indications that production would be gradually reduced. These indications showed that productions sustainability is not guaranteed in old stands. Average biomass and kayu putih oil varied among sites. Leaf-twig production in site I was estimated at 2.42 t ha-1 yr-1, followed by G at 1.97 t ha-1 yr-1 and P at 1.42 t ha-1 yr-1. Oil production in site I was also higher than other two sites. Alluvial soil and availability of stagnated water like a paddy-field may have contributed to high production in site I. The tree basically grows better in the areas of high water availability, with combinations of other favorable environmental factors.Exploitation on kayu putih plantation resulted in large amount of annual biomass removal. The tree cannot assist and protect soil fertility, as well as crop productions. Treatment is needed to maintain production sustainability for older stands (30 years and up).
