Impact of bauxite mine to natural forest biomass and soil properties in Kas Island, Riau Island Province in Indonesia

In this investigation, the impact of bauxite mine to natural forest biomass and soil properties in Kas Island, Riau Island Province in Indonesia was investigated. On the island of  Kas, bauxite mining permits have been issued. Mining activities will cause the destruction of natural forests as a source of wood, loss of flora and fauna, water regulator and medicines, besides it will also cause damage to land and the environment. Reclamation activities undertaken aimed at improving the vegetation structure and soil characteristics that undergo changes due to mine. The research method used is the analysis of vegetation and soil sampling is done by purposive sampling. Laboratory test data from physical and chemical properties of the soil, were analyzed by descriptive and statistical tests.  Bauxite mining activities have caused the loss of biomass of natural forests by 168.8 tons / ha. Revegetation activities on bauxite mining sites should be restored through planting trees of Pulcherrimum sp, Laplacea subintegerrima, Calophyllum soulatri, Thesposia populnea, Diosphyros sp, Schima wallichii and Hopea mangarawan. Bauxite mining activities cause changes in soil properties, namely a significant increase in bulk density of 0.55 (76.39%) and a significant decrease in porosity of 22.39 (30.21%), drainage pore of 6.57 (52.77%), water available at 6.41 (36.59 %), permeability is 19.59 (82.69%), C-organic is 12.20 (93.99%), N  is 0.47 (85.45%), and P  is 29.88 (85.91%). Therefore, bauxite mine activity leads to significant changes in physical properties and soil chemistry properties for bulk density parameters, porosity, drainage pores, available water, and permeability, C-organic, nitrogen (N) and phosphorus (P) of the soil.