Dinâmica espaço-temporal do estoque de carbono do solo nas áreas de silvicultura do Brasil (1985-2023)

Abstract

The production of planted forests is recognized as an activity with the potential to mitigate climate change by storing carbon in trees, wood products, and soil. The soil, being the largest reservoir of organic carbon, plays a crucial role in the emission or absorption of carbon dioxide, influenced by the management techniques adopted. Soil organic carbon (SOC) is also an essential indicator of soil quality and health, making it fundamental to understand its distribution in the environment. This study analyzed the spatial-temporal dynamics of SOC stock mapping in forestry areas in Brazil from 1985 to 2023. The research aims to understand changes in SOC stocks and their relationships with silvicultural systems, contributing to the evaluation of these systems' efficiency in mitigating climate change and promoting environmental sustainability. The methodology included analyzing the evolution of land use by forestry, expanding the spatial and temporal coverage of soil data, and integrating sample data from the SoilData repository into a comprehensive dataset. A Random Forest model was trained and validated to estimate SOC stocks in the top 30 cm of soil, using both static and dynamic environmental covariates. The results showed a significant increase in total SOC stocks in forestry areas, accompanying the expansion of this activity in the country. The predictive model demonstrated good performance, with an RMSE of 22.15 t/ha and an NSE of 0.87, outperforming initiatives like MapBiomas Solo. However, a slight reduction in the average stock per hectare was observed, attributed to the incorporation of areas with soils less rich in carbon. This study offers a tool that can support the development of public policies and management practices that balance forest production with soil conservation, reinforcing the role of forestry in environmental sustainability and climate change mitigation.