Soil Carbon Dynamics in Pasture and Forest Ecosystems

The cycling of carbon within soils of pasture and forest ecosystems underpins terrestrial carbon balance and influences climate regulation. In forest soils, deep root systems and continuous litterfall promote the accumulation of organic matter across multiple soil horizons, whereas pasture soils often depend on grass root turnover and management interventions to maintain soil organic carbon (SOC) stocks. Transitions between forest and pasture alter soil structure, microbial activity and the partitioning of labile and stable carbon pools. Changes in vegetation cover affect bulk density, aggregate stability and decomposition rates, driving either net sequestration or release of carbon. Globally, practices such as silvopastoral integration, rotational grazing and reforestation have demonstrated potential to enhance SOC, mitigate greenhouse gas emissions and improve soil health. Recent advances in isotopic tracing, soil fractionation and modelling now allow finer resolution of carbon turnover dynamics, informing land-management strategies that balance productivity with ecosystem resilience and climate-mitigation goals.

Research from Nature Portfolio

Recent studies have shown that the composition of understory vegetation, particularly the balance of C3 trees and C4 grasses, governs soil carbon recovery during fallow succession in tropical forests. Isotopic analysis revealed that early fallow periods exhibit significant inputs of grass-derived carbon, which supports rapid SOC restoration in both surface and deeper layers. Over longer fallows, the proportion of C4 carbon declines as tree-derived inputs dominate, illustrating how plant functional type shifts drive the trajectory of soil carbon sequestration.

Soil Carbon Dynamics in Pasture and Forest Ecosystems publication trend

The graph below shows the total number of articles in soil carbon dynamics in pasture and forest ecosystems across all publications each year (not limited to Nature Index journals).

Technical terms

Soil organic carbon (SOC): Carbon component of soil organic matter derived from decomposed plant, animal and microbial residues.

C3 and C4 plants: Plant groups distinguished by their photosynthetic pathways, which influence carbon isotope signatures and decomposition rates.

Bulk density: Mass of dry soil per unit volume, affecting porosity and the capacity for carbon storage.

Stable isotope analysis: Use of natural isotope ratios (e.g. 13C/12C) to trace sources and turnover of soil carbon.

Sequestration: Long-term storage of carbon in soil organic matter, reducing atmospheric CO₂ concentrations.

References

1. Effects of Agricultural Expansion on Soil Carbon and Nitrogen Stocks in the Amazon Deforestation Arc. Soil Systems (2024).
2. Forest understories controlled the soil organic carbon stock during the fallow period in African tropical forest: a 13C analysis. Scientific Reports (2019).
3. Soil carbon stocks and nitrous oxide emissions of pasture systems in Orinoquía region of Colombia: Potential for developing land-based greenhouse gas removal projects. Frontiers in Climate (2022).