Earthworms as catalysts in the formation and stabilization of soil microbial necromass

Summary

Microbial necromass is a central component of soil organic matter (SOM), whose management may be essential in mitigating atmospheric CO₂ concentrations and climate change. Current consensus regards the magnitude of microbial necromass production to be heavily dependent on the carbon use efficiency of microorganisms, which is strongly influenced by the quality of the organic matter inputs these organisms feed on. However, recent concepts neglect agents relevant in many soils: earthworms. We argue that the activity of earthworms accelerates the formation of microbial necromass stabilized in aggregates and organo-mineral associations and reduces the relevance of the quality of pre-existing organic matter in this process. Earthworms achieve this through the creation of transient hot