Mapping the silence of the soil: the dynamics of soil organic carbon from 1987 to 2023 in Mato Grosso

Abstract

Maintaining soil carbon is fundamental for fertility, water retention, and climate equilibrium. However, deforestation without an adequate management program accelerates the loss of soil organic carbon (SOC), intensifying erosion and releasing CO₂, thereby compromising ecosystem services. This study investigates the spatiotemporal dynamics of SOC in the state of Mato Grosso, Brazil, focusing on the implications of deforestation and agricultural expansion for the stability of this element. The aim of the study is to analyze trends between 1987 and 2023, using integrated data from the MapBiomas Solo v2.0 platform, Google Earth Engine, and QGIS, combining geotechnologies with analyses of historical land use. The methodology involved time series analysis and the production of thematic maps, validated through statistical metrics such as RMSE and R². Results indicate a modest overall increase (0.88%) in SOC stocks during the period, but highlight a concerning expansion of areas with low carbon content; regions of intense deforestation, such as the Pantanal and Cerrado, exhibited pronounced vulnerability to carbon loss, whereas Indigenous lands and conservation units emerged as carbon stock hotspots. The discussion emphasizes that, although conservation practices can mitigate losses, restoring natural stocks requires continuous action, specific policies, and incentives such as carbon credits. It is concluded that systematic monitoring and the protection of priority areas are indispensable for regional edaphic resilience. Strengthening databases and establishing a national SOC inventory are recommended to support public policies and climate adaptation strategies.