Roots from beech (Fagus sylvatica L.) and ash (Fraxinus excelsior L.) differentially affect soil microorganisms and carbon dynamics

► Rhizodeposition of beech reduced soil C by decreasing C use efficiency of bacteria. ► More litter-derived carbon reached higher trophic levels in soil planted with ash. ► Bacteria and fungi form different energy channels in soil planted with beech. ► In particular the roots of beech alter C dynamics in soil.