Stabilized microbial necromass in soil is more strongly coupled with microbial diversity than the bioavailability of plant inputs

Summary

Microbial necromass carbon (C) can substantially contribute to stabilized soil organic matter (SOM), and effective management of this C may help mitigate climate change. However, factors important to the formation of microbial necromass are only partly understood. While bioavailable plant inputs may induce necromass formation by boosting microbial growth and C use efficiency, other microbial traits, such as those related to secretion systems or adhesion and motility, may also be relevant. These traits may be independent of the bioavailability of plant inputs and modulated by environmental factors such as soil depth or site age. Such links, however, have hardly been studied. Here, we used replicated plots of European alder (more bioavailable inputs) and Scots pine (less bioavailable inputs)