Land-use Changes and their Causes in the Tropics: A Case Study in South Sumatra, Indonesia in 1969-1988.

Abstract

Land-use changes in the period between 1969 and 1988 of 38, 480 sq km areas in South Sumatra were examined. Those two periods of land-use map were digitized and input as Geographical Information System (GIS) data base using Arcllnfo software packages. Quantitative analysis of land-use changes was carried out by overlay technique. Other related factors such as timber concession, and land tenure system changes, were also examined. It has been believed that the deforestation in South Sumatra was caused by timber concession exploitation that have mostly been started in 1968. Our observation, however, shows that most deforestation had occurred before 1968. In 1969, forest area only covered about 35%, while regrowth and cultivated land accounted for 37% and 26% of the total area, respectively. Therefore, the loss of forest might be related to other factors such as cash crop introduction in the early nineteenth century and road construction for oil exploration in the beginning of twentieth century. There was clear evidence that in South Sumatra, timber concessions’ exploitation that was started in 1968, had less impact on forest cover than other land uses. This was demonstrated by the fact that during 1969-1988, in concession area about 74% of forest areas still remained unchanged, in comparison with only 42% in non concession. Moreover, there was much more forest regeneration from regrowth and cultivated land. In total, during 19 years period, forest cover area decreased by less than 10%. This was partially explained by forest regeneration, and the changes of land tenure system (marga system) that made farmers difficult to access forest land.