The Sustainability of Teak Forest Management in Cepu, Central Java, Indonesia: A Soil Resources Point of View

Indonesia has been known as one of the major teak producers in the world. However, lately the quantity and quality of Indonesian teak has been getting worst. It was thought that the decrease in the quantity and quality of the Indonesian teak was caused by the improper growth of the tree due to decreasing soil quality as a result of accelerated soil erosion. To test this hypothesis, field experiments were done in the Cepu teak plantation, Central Java. With the existing forest management, the average soil erosion rate is 20.6 t/ha/year, far higher than the permissible soil erosion of 15 t/ha/year. If this rate is allowed to proceed continuously, the soil will be unproductive for the next 100 years. With the existing management, the harvesting of teak trees should be done for those over 60 years old; harvesting younger trees would speed up land degradation. Improving intercrop trees, shrubs, and cover crops growth as well as maintenance of the forest litter in the teak forests are absolutely essential. Planting spice crops under teak trees could help maintain the coverage of the forest floor, and hence promote sustainable teak forest production.