Fig. 6

Structural equation modeling (SEM) depicting the effect paths of extreme drought treatments, precipitation in the early growing season (March to June), functional trait and soil properties on above- and belowground biomass. Square boxes indicate variables included in the model. Single headed arrows indicate paths. Numbers on path is the standardized regression weights. Total explained variance (R2) of biomass is on the right corner of boxes. Using the *, ** and*** to show the significance along the paths at the level of P < 0.05, P < 0.01and P < 0.001. Results of model fitting: \({\upchi }^{2}\)=16.936, P = 0.110, RMSEA = 0.087, GFI = 0.943