Abstract: We measured soluble protein concentration, hydrogen peroxide (H₂O₂) concentration, total antioxidant level and other biochemical indices of samples of dominant moss Polytrichum commune Hedw., which were collected from the acid mine wastewater basin of arsenic-rich coal district and nearby unpolluted area in the upper reaches of Maoshitou Reservoir of Xingren County, Guizhou Province. The biogeochemical characteristics of P. commune in the arsenicrich coal district under the conditions of arsenic oxidative stress were examined. The results showed that P. commune absorbed arsenic which was involved in metabolism. The soluble protein concentration in P. commune in the polluted area was lower, with a lowest value of 0.151 mg·g^-1 in the water outlet of mine hole, while the value was up to 0.404 mg·g^-1 in the unpolluted area. The concentration of soluble protein had negative correlation with arsenic concentration across all sampling locations. The belowground part of P. commune had lower soluble protein concentration than aboveground part. The active oxygen (ROS) in P. commune was accumulated, indicating that the arsenic oxidative stress on P. commune. The H₂O₂ concentration of P. commune in the polluted area was up to 5.93 μmol·g^-1, being obviously higher than that in the unpolluted area (3.37 μmol·g^-1). The belowground part had lower H₂O₂ concentration than the aboveground part. The H₂O₂ concentration had a positive correlation with the arsenic concentration. P. commune in the polluted area was resistant to the arsenic oxidative stress to a certain degree. The total antioxidant level was significantly decreased under extremely high concentration of arsenic. The ferric reducing/antioxidant power (FRAP value) of site A3 was 0.577. The arsenic concentration was relatively low in the sampling locations after site A3, with the FRAP value being generally stable.

Key words: biodiversity, species resource, biocontrol preparation., endoparasitic fungi