3.4 Intra-annual community biomass stability and its relationship with climatic and biotic factors
Intra-annual community stability of biomass (Fig. 5a; P = 0.009, R2 = 0.23) and intra-annual species asynchrony (Fig. 5h; P = 0.000, R2 = 0.51) tended to increase during the period 1981–2011. In contrast, intra-annual biomass stability of the functional group PF trended to decrease (Fig. 5d; P = 0.001; R2 = 0.35) during the 29-year observation period. Intra-annual biomass stability of dominant species and functional groups PR, PB, SS and AB showed no obvious change (Fig. 5b-c, e-g).
Intra-annual biomass stability of functional group PB was positively correlated with P8 and P8-9, but negatively correlated with P4-7, T8 and T5-9. Intra-annual biomass stability of functional group PF was positively correlated with P7, P6-9 and P7-9. Intra-annual biomass stability of functional group AB was positively correlated with precipitation in the growing season, including P1-7, P4-7, P5-7 and P6-7. In contrast, we didn’t find correlation between climate factors and intra-annual stability of community biomass, functional groups biomass of PR and SS, and dominant species biomass (Table 1).