A chronosequence study of soil properties and microclimate in the reclamation area of Batu Hijau Mine, West Sumbawa

The objective of this study was to characterize soil physical and chemical properties, development of soil and microclimate condition according to the time sequence of revegetation. Sampling and observation were conducted in revegetation areas aged 2 to 8 years old and in the natural forest for comparison. Disturbed soil samples were taken from three depths while undisturbed soil samples were taken from two depths. Light intensity, air temperature, humidity and soil temperature were measured for microclimate analysis. The results showed that the soil had clay loam and loam texture with relatively high density and low permeability. Natural forest soil had lower density and higher permeability. Low soil fertility was indicated by low organic-C, total-N, available P and exchangeable K. Exchangeable-Ca and -Mg and cation exchange capacity of the soil in revegetation area were higher than in the natural forest soil. Only the content of organic-C and total-N in the first 5 cm layer of the soil increased along with the increasing revegetation age, while other parameters of soil properties showed no differences. Falcataria moluccana, Anthocephalus cadamba and Melochia umbelata were the dominant vegetation found in sapling, pole and tree. Light intensity, air temperature and soil temperature tended to decrease, while humidity increased with the increasing age of revegetation.