Correlation between soil microorganism, soil enzyme activity and arsenic contamination in the tungsten mining area

The status of arsenic pollution status and the influence of arsenic concentration and its form on mi - croflora composition and soil enzyme activity are analyzed in Gannan tungsten area by field sampling. The re - sult indicates that the concentrations of As in soil are significantly higher than those in the non-mining area, in which As mainly appears as Fe-Mn oxides bound ,and exchangeable As with high bioavailability are 9.8 %~ 12 %.As mainly exists in form of residua in the trailing sand which accounts for 39.7 %, and exchangeable As is 16.6 %.There are negative correlations between the influence of the total amount of arsenic and available As on the biomass of soil microorganisms in the mining area. The microflora composition decreased obviously at polluted mine soil, and the susceptive order of three soil micro-organism to As is as follows: bacteria > actino - mycetes >fungi. Soil urease, catalase and sucrase activity are suppressed by arsenic pollution. Urease activity is proved to be a good indicator to the soil pollution level in the tungsten area through correlation analyzing. To some degree, the microflora composition and activity of soil enzyme microorganism can reflect the charac - teristics of heavy metal pollution and its evolvement law of ecological function of the polluted habitat in that tungsten mine area.