Plant functional traits affect biomass responses to global change: a meta-analysis

Whether and how the responses of above- (AGB) and belowground biomass (BGB) and aboveground net primary production (ANPP) to global changes are linked to plant functional traits is unclear. We conducted a global meta-analysis based on 2561 observations from 318 manipulative studies (primarily forest, grassland and cropland monocultures) to examine the effect of plant functional traits of dominant species (i.e., morphological and chemical traits, mycorrhizal association type and symbiotic nitrogen (N) fixation) on the responses of plant biomass production to global change drivers, i.e., elevated CO₂ (eCO₂), elevated nutrient (eNutrient), elevated water (eWater), warming, and drought.We test following hypotheses (1) the responses of biomass production to GCDs will be stronger in plant communities dominated by fast-growing species than in those dominated by slow-growing species; (2) the responses of plant biomass production in EcM species-dominated communities to eCO₂, eWater, warming and drought will be stronger than those in AM species-dominated communities, but the response of plant biomass production to eNutrient will be stronger in communities dominated by AM species than those dominated by EcM species; (3) the response of plant biomass production to eCO₂, eWater, warming and drought will be more pronounced in communities dominated by N-fixing species than that dominated by non-N-fixing plants, while the reverse response will be found to eNutrient.