The impact of shifting cultivation on a rainforest landscape in West Kalimantan: spatial and temporal dynamics

To assess the role of shifting cultivation in the loss of rainforests in In donesia, we examined the spatial and temporal dynamics of traditional land- use north of Gunung Palung National Park in West Kalimantan. We analyzed th e abundance, size, frequency, and stature (by tree size) of discrete manage ment units (patches) as a function of land-use category and distance from t he village. Data were gathered from point samples along six 1.5-km transect s through the landscape surrounding the Dayak village of Kembera. Most land was managed for rice, with 5% in current production, 12% in wet-rice fallo ws (regenerating swamp forest), and 62% in dry-rice fallows (regenerating u pland forest). The proportion of land in dry-rice increased with distance f rom the village; rubber gardens (17% of the total area), dominated close to the village. The size of rubber trees declined with distance, reflecting t he recent establishment of rubber gardens far from the village. Fruit garde ns accounted for only 4% of the area. From interviews in Kembera and three other villages, we estimated rates of primary forest clearing and documente d changes in land-use. Most rice fields were cleared from secondary forest fallows. However, 17% of dry-rice fields and 9% of wet-rice fields were cle ared from primary forest in 1990, resulting in the loss of approximately 12 ha of primary forest per village. Almost all dry-rice fields cleared from primary forest were immediately converted to rubber gardens, as were 39% of all dry-rice fields cleared from fallows. The rate of primary forest conve rsion increased dramatically from 1990 to 1995, due not to soil degradation or population growth but rather to changes in the socio-economic and polit ical environment faced by shifting cultivators. Although the loss of primar y forest is appreciable under shifting cultivation, the impact is less than that of the major alternative land-uses in the region: timber extraction a nd oil palm plantations.