RECOVERY OF VEGETATION STRUCTURE, SOIL NUTRIENTS AND LATE-SUCCESSION SPECIES AFTER SHIFTING CULTIVATION IN CENTRAL KALIMANTAN, INDONESIA

Abstract

Recovery of vegetation and soil nutrients in abandoned shifting cultivation areas can provide important information, important for forest rehabilitation. For better understanding of forest recovery after the cessation of shifting cultivation, soil nutrients and vegetation structure of fallow areas were monitored at 1, 5 and 10 years after abandonment in a primary forest plot. The results showed that the number of species, the Shannon indices of diversity and evenness of large trees (diameter at breast height > 20 cm) increased with time after abandonment. Late-successional species in primary tropical rainforests, e.g. Shorea sp., was found 1, 5 and 10 years after abandonment. Soil organic carbon and total nitrogen levels were low in all plots and at all soil depths except in surface soil (0–2 cm), and did not significantly differ between among plots. Available phosphorous content was significantly different between the plot that had been fallow for one year and the rest of the plots, for both combined and each soil depth. It was concluded that changes in vegetation composition did not affect the status of soil nutrients in the young fallow plots, which can support the growth of late succession species.