Fig. 6
Structural equation models of the impacts of acid rain on fine root decomposition rate. (χ2 = 5.325; p = 0.324 > 0.05; GFI = 0.952 > 0.900; RMSEA = 0.077 < 0.08). Numbers on arrows are standardized path coefficients. Solid lines indicate the direct influence of each parameter on the decomposition rate and dotted lines indicate the indirect influence of acid rain on the decomposition rate through changing soil or root parameters. pHs, soil pH, phosphatase, soil acid phosphatase activity; urease, soil urease activity; Car, calcium content of fine root litter; C/Nr, C/N ratio of fine root litter; rate, fine root litter decomposition rate; S/N, the ratio of SO42− to NO3−; pH, acid rain pH