Earthworm biopores for transport and nutrient cycling

Earthworms build a complex network of stable biopores with diameters of up to 0.5 cm existing over years and decades in soil. Besides the direct habitat and pathway functions for the earthworms, the biopores strongly accelerate the diffusion and migration of gases, solutions, nutrients, and organic substances, as well as mineral particles within the soil profile and link the top with subsoil. After a short introduction to pore classification and formation mechanisms, we focus on the functions of biopores produced by earthworms as relate not only to the transport processes. We conclude that biopores are real hotspots of transport, and cycling of elements, where the turnover of C, N, and P is intensively ongoing. Concludingly, biopores formed by earthworms are important for the fast transport of gases, solutions, and nutrients, provide highways for root growth into the subsoil for nutrient and water acquisition, contribute to C sequestration, and therefore are one of the ways for the amelioration of soil by natural processes. The higher C input into biopores enriches C and N in the subsoil. In general, earthworms increase SOM turnover and cycling of elements by stimulating microbial activity, especially in the subsoil. Consequently, it is very crucial to assess the spatial and temporal distribution of the density of biological voids and their effectiveness for the reliable representation of the coarse flow and the transfer of elements in the soil. © 2025 Elsevier B.V., All rights reserved.