Data from: Positive plant diversity effects on soil microbial drought resistance are linked to variation in labile carbon and microbial community structure

Biodiversity loss and drought are substantially altering both above-and
belowground terrestrial ecosystem functioning, but mechanistic
understanding of plant diversity effects on the drought resistance of soil
microbial biomass remains limited.  We designed a mesocosm
experiment to examine drought resistance of soil microbial biomass along a
plant species richness gradient (five plant species richness levels based
on old-field communities). We calculated resistance of microbial biomass
to drought and recorded key belowground properties which may influence
microbial resistance to drought (i.e., microbial diversity, microbial
community structure, soil carbon stocks and root biomass).  Plant
species richness had a positive effect on microbial resistance to drought.
Variation in microbial resistance to drought was linked to properties of
the fungal community in ambient soil (Shannon diversity, arbuscular
mycorrhizal fungal richness and abundance) but not soil bacterial
diversity. Moreover, microbial resistance to drought increased with
increasing root biomass and dissolved organic carbon recorded under
ambient conditions.  These results highlight the importance of
plant diversity for microbial biomass stability in our old-field study
system with implications for biogeochemical cycling, and suggest that
indirect effects of plant species richness on labile soil carbon and soil
fungi may drive resistance of soil microbial biomass to drought.