Morpho-anatomical traits explain the effects of bacterial-feeding nematodes on soil bacterial community composition and plant growth and nutrition

•● Bacterivorous nematode species differentially promoted plant growth and nutrition.•● Predation by bacterial-feeding nematodes altered the soil bacterial communities.•● Nematode effects were predicted better by traits than by cp classes or species identity.•● Body and egg sizes as well as mouth and procorpus width were likely effect traits.•● The trait approach could explain the variable effect of nematodes on ecosystem functions.