Soil carbon stocks, ecosystem services and soil quality in the Pontal do Paranapanema region, Brazil

Abstract

Sustainable soil management is essential to ensure agricultural productivity, conserve natural resources, and maintain the ecosystem services that support environmental balance in the face of climate challenges. This study aimed to assess the ecological sustainability of soils in the Pontal do Paranapanema region (São Paulo, Brazil) under various land uses, focusing on carbon stocks, ecosystem services, and soil quality across four municipalities in the region. First, carbon stocks were evaluated in coarse-textured Oxisols and Ultisols under six contrasting land uses. Then, an ecosystem services (ES) index was proposed for the region, considering indicators of carbon sequestration (representing the storage of C in the soil), carbon cycling (referring to the dynamics and transformation of C in ecosystems), soil fertility (availability of nutrients to plants), soil structure, and water regulation (capacity to absorb, move, and store water). Finally, the influence of microbiological indicators on the physical and chemical quality of these soils was investigated.Results showed that in both soil types, the lowest carbon stocks occurred under cassava cultivation. In Ultisols, forest restoration and sugarcane exhibited the highest soil organic carbon (SOC) stocks, while in Oxisols, the highest stocks were observed under primary forests and pastures, suggesting that systems with perennial crops or grasses and minimal soil disturbance are effective in preserving or even enhancing SOC sequestration. The ecosystem services index ranged from 0.51 under cassava cultivation to 0.76 under forest restoration, highlighting its potential as a strategic tool to support sustainable soil management in tropical regions such as the Atlantic Forest biome. This indicates that, when properly managed, soils have a greater capacity to provide ES.Microbiological indicators—such as microbial biomass carbon, β-glucosidase activity, basal respiration, and the metabolic quotient—were sensitive to land use and showed clear responses to management practices. Integrating these indicators into soil quality assessments allows for a deeper understanding of biological processes and their relevance to the sustainability and functionality of tropical soils. This study also emphasizes the need for sustainable agricultural practices to preserve soil structure and microbial communities, ensuring soil resilience and functionality. Aligned with the United Nations Sustainable Development Goals (SDGs), this research contributes to climate change mitigation (SDG 13), terrestrial ecosystem conservation (SDG 15), responsible use of natural resources (SDG 12), and the promotion of sustainable agriculture (SDG 2). This interdisciplinary approach not only expands scientific knowledge on the impacts of land use on soil ecosystem services but also provides direct support to farmers and environmental managers in adopting more responsible and effective practices, ensuring the resilience of tropical soils in the face of increasing environmental and climate demands.