In the tropical forest areas the endogenous development mechanisms would be hardly formed, because the areas have been under the influence of exogenous economic forces as the areas have been the periphery regions in the periphery countries. The patterns of changes in forest utilization in the tropics, however, do not seem to be uniform. This paper describes and considers the changes in swidden agriculture and the customary law concerning the utilization of the forest products, based on the field surveys at the Kenyah Dayak and the Buginese villages in East Kalimantan, the Wana villages in Central Sulawesi and a village in Siberut island.
Traditional types of swidden agriculture, which produce subsistence crops under the condition of the low population density, whether recurrent type or pioneer type, seem to change toward unsustainable land utilization in the course of economic development along with population increases and the infiltration of cash economy, because the practices concerning the use of swiddens are not so strict as customary law would imply.
In utilizing the forest products, it is crucial whether the customary law has developed well or not before going through the economic development. The areas where the customary law have developed well will possibly develop endogenously, or form the conditions, suitable to peculiar ecosystems, for everybody as individual human being to make good use of the possibilities through satisfying the basic human needs based on their own tradition, referring to exogenous knowledge, technology, institution, etc.. Even in the society with elaborately developed customary law, however, it is uncertain how long the customary law will be effective, because of the contradiction with the national law and the influence of radical economic development. It seems necessary to form the system where forest dwellers could manage the forests with the assurance of the long term right of utilization.