Revegetation of tin post-mining sites in Bangka Island to enhance soil surface development

Abstract

Sandy tailing, a by-product of tin processing plant is commonly utilized for land preparation for revegetation. In some cases in the land reclamation, slime (clayey) and lateritic materials are also used. Mining company has an obligation to improve environmental quality by which revegetation is introduced using a variety of introduced fast growing species and local species. In this paper we have examined soil surface development under different plant species in tin post-mining area in Bangka Island. The study was carried out in Air Benuang (planted in 2017, Anacardium, 1 m height), Air Pelawan 2 (planted in 2017, Paraserianthes falcataria, 6 m height), Air Pelawan 1 (planted in 2015, rubber trees, 2 m height), Batu Ampar (2007, Acacia mangium, 10 m height), and a secondary forest in Air Mesu. In every site a small pit was excavated and some soil physical properties were analyzed in site as well as in laboratory. The results indicated that surface soil of recently revegetated sites has gradually changed into slightly darker from light yellowish brown (10 YR 6/4) into 10 YR 3/1 owing to such addition of organic matter and topsoil during sites preparation. Meanwhile, for the older site of Batu Ampar remains grey (10 YR 5/1-6/1) due to less incorporation of decomposing litter of Acacia. Revegetation also enhances decrease of bulk density with age of reclamation. Water infiltration is likely related to the amount of sand fraction but not with the age of revegetation. We learn from the results that plant selection for revegetation is the key factor to ensure a long-term recovery of soil surface condition.