Grazing of animals can contribute to increasing the capacity of soils to store carbon, contrary to the idea that removing cattle from pastures necessarily benefits carbon retention. The conclusion results from a study conducted on subarctic pastures of Iceland and published in the journal Global Change Biology Communications.
The researchers analyzed data obtained under real-world conditions, monitoring areas where grazing had been interrupted for extended periods. The results showed that the cessation of grazing was associated with lower soil carbon levels, while areas where the animals continued to graze consistently exhibited higher levels of stored carbon.
The researchers also observed changes in vegetation composition. The prolonged interruption of grazing favored a shift to plant communities associated with soils with lower carbon content.
Pasture plants transfer large amounts of carbon to the soil through their roots, with a significant portion of this carbon stored in the subsoil. For this reason, increasing the soils’ capacity to retain carbon is considered important in the context of climate change.
The idea that removing animals from pastures favors carbon storage has often been assumed, but the new results suggest that the relationship may be more complex and depend on ecosystem characteristics.
“The results have important implications for climate policy, nature-based solutions, and the sustainable management of pastures worldwide,” says the corresponding author, Anna Gudrun Thorhallsdottir, professor at the University of Iceland at Holar.
According to the researcher, the conclusions “highlight the potential importance of grazing for maintaining pastures and increasing soil carbon storage.”
The study is, however, based on evidence from subarctic pastures in Iceland, so the results do not allow us to assume that grazing has the same effect on all types of pastures or environmental conditions.
