Enzymes in Arctic soils break down organic matter, but their activity is influenced by the type of organic matter and the microbes present. In Siberian Arctic soils, where topsoil is mixed into deeper layers (cryoturbation), the microbial community is not well-suited to the organic matter properties. Enzyme activity in regular soil layers is mainly controlled by carbon or nitrogen content, while in cryoturbated material, microbial community composition also plays a role. This mismatch between organic matter properties and microbial community may slow down decomposition, leading to the storage of a large amount of carbon in cryoturbated soils.