Novel framework allows for a more effective management of soils as carbon sinks
Report by Dr Gerrit Angst, postdoctoral researcher of the Experimental Interaction Ecology at iDiv, Leipzig University, and the Czech Academy of Sciences and first author:
Leipzig/Budweis/Copenhagen. Increased carbon sequestration in soil to help mitigate climate change can only be achieved by a more holistic management. This is the conclusion from our opinion paper conceptualized together with colleagues from the German Centre for Integrative Biodiversity Research (iDiv), Leipzig University, the Czech Academy of Sciences, and the University of Copenhagen. We developed a novel framework that can guide informed and effective management of soils as carbon sinks. The study has recently been published in Nature Communications.
A key question for land management is how to sustain and increase the vast amounts of carbon stored in soil to help mitigate climate change. In contrast to carbon contained in partly decomposed plant fragments, which is considered labile and remains in the soil for a few days to years, carbon associated with minerals, which can persist for centuries to millennia in soil, has received specific attention as a potential management target. Undifferentiated focus on this "stabilized" carbon, however, falls short of establishing soils as carbon sinks because various environmental factors, such as related to land use or specific soil types, render management of this carbon inefficient. We were puzzled by the strong emphasis on mineral-associated carbon in the literature, whose context-independent valuation hampers informed and targeted management of soils as carbon sinks. Together with colleagues from Germany, the Czech Republic, the United States, and Denmark, we thus developed a framework for the contextualization of management strategies that considers the diversity and complexity of soils.
Our framework specifically highlights the relevance of labile carbon in partly decomposed plant fragments as a management target in various environmental contexts. For example, the capacity of some soils to accumulate rather stable, mineral-associated carbon is very low; some soils also feature conditions that hamper the formation of stabilized carbon but favor the accumulation of labile carbon. Management that is aimed at increasing and perpetuating labile carbon in such soils will be more effective in increasing carbon sequestration than that focused on stabilized carbon. We cannot overemphasize the need to consider context-dependent environmental conditions for an effective management of soils as carbon sinks, which constrain whether management should target labile or stabilized carbon, or both.
We expect contextualization of management strategies within the novel framework to maximize carbon sequestration in soil and generate synergies with related management targets, such as related to soil health, biodiversity, or crop performance. Only if we see soils as a complex, holistic system with its specific chemical, physical, and biological features, will we be able to successfully manage them in a rapidly changing environment.
Original publication
(Scientists with iDiv affiliation in bold)
Angst, G., Mueller, K.E., Castellano, M.J., Vogel, C., Wiesmeier, M., Mueller, C.W. (2023): Unlocking complex soil systems as carbon sinks: multi-pool management as the key. Nature Communications. DOI: 10.1038/s41467-023-38700-5
