Abstract: Selecting four sites with different degrees of Miscanthus floridulus natural inhabitation and one bare site in Sanmen mine tailings of Zhejiang Province as test objectives, this paper studied the effects of M. floridulus inhabitation on the heavy metals (Pb, Zn, Cu, and Cd) form transformation, microbial parameters, and their relationships in the mine tailings. The results indicated that M. floridulus natural inhabitation increased the fractions of carbonates-bound and sulphides-organic matter- bound heavy metals (P<0.05), but decreased those of exchangeable, iron-manganese oxides- bound, and residual heavy metals (P<0.05). Except the decrease of microbial respiration quotient (P<0.05) and no regular change of microbial biomass carbon quotient, the other microbial parameters increased with increasing natural inhabitation of M. floridulus (P<0.05). Canonical correlation analysis (CCA) showed that the overall changes of microbial parameters had significant positive correlations with the fractions of carbonates-bound and sulphides-organic matter- bound heavy metals (R2=09874, 09939), and significant negative correlations with exchangeable, iron-manganese oxides- bound, and residual heavy metals (R2=09972, 09964, 09949).

Key words: Meiliang Bay, Photosynthetically available radiation (PAR), Suspended solid, Diffuse attenuation coefficient, Euphotic depth