Modeling regional aboveground carbon stock dynamics affected by land use and land cover changes

Land use and land cover changes are affected by massive construction, urban expansion, and exploitative agricultural management. These pressures threaten the potential of aboveground carbon storage in Rancakalong District, West Java, Indonesia. In that massive construction and agricultural expansion are ongoing, it is critical to detect the potential changes in carbon stocks in the region. This study evaluated the impact of land use and land cover changes on aboveground carbon stock potential in Rancakalong District, West Java, Indonesia, by incorporating several ground-based carbon inventories into geographic information systems and remote sensing approaches. The spatiotemporal dynamics of the aboveground carbon stocks were assessed using Integrated Valuation of Ecosystem Services and Tradeoffs models.

Aboveground carbon stocks were estimated using the integrated approach of field inventory and geographic information systems. Land use and land cover changes were assessed from remotely sensed imagery data recorded in 2009 and 2021 using the maximum likelihood classification method in the geographic information as a collection of layers and other elements in a map 10.6 package. Tree height and diameter were collected within the purposively distributed plots with a size of 30 × 30 square meters. Vegetation biomass was assessed using an allometric equation, and aboveground carbon stock data were extrapolated to the landscape scale using a linear regression model of measured carbon stocks and the Normalized Difference Vegetation Index derived from recent satellite imagery.

Vegetated areas were predominant in 2009 and 2021. Vegetation covered 51 percent of the total area in 2009, increasing to 57 percent in 2021. Regarding agricultural area, mixed gardens and drylands decreased between 2009 and 2021. Meanwhile, paddy fields were the only agricultural land use to increase between 2009 and 2021. The bare land and built-up expansion related to the observed land clearing for the Cisumdawu Highway mainly came from the conversion of mixed gardens, paddy fields, and drylands. The results show that the land use and land cover changes in Rancakalong District have caused a reduction in aboveground carbon stocks by 11,096 tons between 2009 and 2021. The highest reduction in aboveground carbon stocks occurred in mixed gardens, while a slight increase in aboveground carbon stocks occurred in forests, shrubs, and paddy fields. The results highlight the contribution of mixed gardens to carbon storage as they are visually similar to forests in the structure and composition of vegetation.

Land use and land cover changes directly affected the aboveground carbon stock potential in Rancakalong District, indicated by an 11,096-ton reduction in the stocks. This shortage of carbon stock potential was mainly attributed to the massive reduction in mixed garden areas between 2009 and 2021 by 12 percent, which caused a significant decrease in aboveground carbon stocks. The application of the Integrated Valuation of Ecosystem Services and Tradeoffs model is efficient in analyzing the effect of land use and land cover change on aboveground carbon stock dynamics and can be widely used in environmental engineering studies involving remote sensing approaches.