Ecologically-based Strategies for Forest Restoration to Meet the Challenge of Deforestation in Thailand

Thailand is one of the remarkable countries where forest ecology has been rapidly changing, as a result of economic development, agriculture, social changes and so on. Rehabilitation with indigenous species, which differs from conventional reforestation, has been attempted in Thailand since 1991, then the methodology and strategies for forest recovery based on phytosociology were examined in rural Thailand. This paper is a complete description of the first method for tropical rehabilitation in Thailand. Unfortunately, for the first 3 years (1991-1993), the species selection was based on villagersknowledge. For reforestation, canopy species such as Sindora siamensis, Afzelia xylocarpa and Pterocarpus macrocarpus have been selected by local villagers. In 1994 a survey of potential natural vegetation was carried out to determine natural vegetation types. Since then, the species selection has been based on field survey. The broad concepts of ecology are applied for a practical restoration system. The planting density is 2-3 individual seedlings per square metre. Mixed-species plantation using potted seedlings, and mulching with rice straw have been applied. The restoration and management have been participated in by rural clients. There is a highly significant difference of planted seedlings between weed control treatment and unweed control treatment. Not only does weed control effect growth rate. both diameter and height, but also survival rate. In 1994 meteorological instruments were set up to measuremicro-climate changes. As a result, the plantation forest can keep soil moisture better than bare land. Plantation forestry and its environment are gradually developing to naturalness. This promising approach implies the possibility to cope with rural ecologlcal restoration for troplcal regions.Contribution from the Department of Vegetation Science, Institute of Environmental Science & Technology, Yokohama Natlonal University No.220