Estimation of potential topsoil organic carbon loss due to industrial complex development: Implications for topsoil conservation in South Korea

Organic carbon in topsoil plays an important role in carbon sequestration to mitigate climate change. Topsoil contains the highest amount of organic carbon in soil layers, and conserving topsoil can provide an important solution to climate change. In South Korea, an extensive amount of topsoil has been lost due to the development of industrial complexes through land conversion. This study aims to quantify the potential organic carbon losses resulting from reductions in forest and agricultural land caused by the development of industrial complexes over three years. Over the past decade, 6.2 % of the national agricultural land (equal to 1302.73 km²) and 1.2 % (equal to 801.68 km²) of forest land were lost. These losses in agricultural and forest land correspond to an estimated loss of soil organic carbon equal to 7,139,356 Mg from the agricultural land and 7,794,831 Mg from forest land. After mineralization, this can result in 551,606 and 1,637,011 Mg of CO₂ being released in the atmosphere from agricultural and forest land respectively. The most significant finding of this study is that the average annual potential organic carbon losses from the reductions of agricultural and forest land due to the development of industrial complexes over a recent three-year period are respectively equivalent to 30 % and 90 % of the average annual nationwide loss over the past 10 years. This indicates the urgent need for effective topsoil management within the Environmental Impact Assessment (EIA) framework. We further examine the current state of topsoil management with the EIA framework, highlighting the need for improved management to mitigate the environmental impacts of topsoil loss. Our results highlight the substantial impact of land conversion on carbon sequestration, underscoring the need for effective topsoil management within the EIA framework.