Grain size controls on cryoturbation and soil organic carbon density in permafrost-affected soils
(English)Manuscript (preprint) (Other academic)
This meta-analysis aims to describe the relationship between grain size distributions and soil organic carbon (SOC) storage in mineral subsoil and carbon (C)-enriched cryoturbated pockets in five areas of continuous permafrost that differ in glaciation history and soil parent materials. Our results show a positive relationship between fine-grained (colloid to medium silt) fractions and SOC storage. Finer textured soils had a significantly higher SOC storage in mineral subsoil samples (not C-enriched through cryoturbation) than coarser textured soils. However, the process of C-enrichment through cryoturbation was most pronounced in soils with coarser grain sizes in the range of coarse silt and very fine sand. Even though fine-grained textures provide a better physical and biochemical protection for soil organic matter, their strong cohesion reduces the mixing of soil horizons and the effectiveness of cryoturbation. A higher % coarse silt to % clay ratio in samples was a good predictor of C-enrichment through cryoturbation across soil samples, soil profiles and study areas.
permafrost soils, SOC storage, cryoturbation, soil parent materials, soil texture, grain size distributions
Earth and Related Environmental Sciences
Research subject Physical Geography
IdentifiersURN: urn:nbn:se:su:diva-137284OAI: oai:DiVA.org:su-137284DiVA: diva2:1061499