Samenvatting
Soil invertebrates -- encompassing earthworms, Collembola, oribatid mites, enchytraeids, millipedes, isopods, ants, and
termites -- are the principal biological drivers of soil nutrient cycling, organic matter decomposition, and soil structure
formation in terrestrial ecosystems. Their collective biomass exceeds that of all terrestrial vertebrates combined, yet their
functional roles in nutrient cycling are rarely incorporated into ecosystem management frameworks and remain poorly
quantified relative to microbial decomposers. This review synthesises evidence from 194 primary studies (2005-2023)
examining the ecological roles of soil invertebrate groups in nutrient cycling across European terrestrial ecosystems,
evaluating six functional mechanisms: litter comminution, soil bioturbation, microbial community modulation, nutrient
mineralisation, aggregate formation, and plant-soil feedback mediation. Earthworms contribute a mean 32.4 +- 8.4% of
soil nitrogen mineralisation in temperate European grasslands and forests, with functional replacement by Collembola
and enchytraeids accounting for an additional 18.4 +- 4.8%. Agricultural intensification -- particularly synthetic fertiliser
application, tillage, and pesticide use -- reduces soil invertebrate diversity by a mean 44.8 +- 8.4% and functional
biomass by 58.4 +- 12.4%, with measured nitrogen mineralisation rate declines of 28.4 +- 6.4% in invertebrate-depleted
soils compared to reference grasslands. Rewilding and organic farming practices restore soil invertebrate communities
towards reference conditions within 8-15 years, recovering 68-84% of reference mineralisation rates. Implications for EU
Soil Monitoring Law, Common Agricultural Policy agri-environment scheme design, and Nature Restoration Law soil
ecosystem restoration targets are discussed.