Dynamics of Soil Carbon Affected by Land Use Changes and Its Relationship with the Addition of Greenhouse Gases in the Atmosphere (Case Study: Sumatera Island)
Dinamika Karbon Tanah Akibat Konversi Lahan dan Hubungannya dengan Penambahan Gas Rumah Kaca di Atmosfer (Studi Kasus : Pulau Sumatera)
Abstract
Soil is the largest carbon storage in terrestrial ecosystems, thus soil plays an important role in the global carbon cycle. The increasing of human needs in terms of economic, social, and institutional are the factors affecting land use change in order to meet the necessities of life. Changes of vegetation / land cover / land use causes changes in biomass and biomass carbon stock. This conditions affecting amount and distribution of plant’s scrabs and tissue underneath which are the main source of soil organic material, thus will affect the soil organic carbon stock. Overall, if the organic soil material changing, the organic carbon will change as well. Changes in land cover can increase carbon loss through several mechanisms, namely: 1) destroy soil aggregates that protect the soil organic materials from decomposition, 2) stimulate microbial’s activity by improving soil aeration, 3) mixing the fresh organic material into soil which the conditions are more favourable for decomposition rather than in the soil surface. In addition, cultivate land more easily eroded, resulting in the loss of carbon. Moreover, land use can cause soil more easily being eroded. This research is aimed to estimate soil carbon emissions due to land use changes that occurred since 2003 to 2006 on mineral soil and peat soil on first soil layer in Sumatra island using the method of soil carbon emissions estimation created by the IPCC in 2006. The amount of emissions that occur due to land use change in mineral soil is 38.435.198 acres, which its emissions is 83.025 tons/year of C or equal to 304.704 ton/year of CO2. While the changes that occur in peatlands in Sumatra to contribute as much 41.236.091 tons/year of C or equal to 151.336.454 tons/year of CO2 for 6.643.778 acres of land area change.