Chin J Plan Ecolo ›› 1983, Vol. 7 ›› Issue (1): 20-30.

• Research Articles • Previous Articles     Next Articles

Studies on the Plants and Their Accumulated Mercury of Wanshan Mercury Ore Deposits in Guizhou Province

Wang Meilin, Kong Lingshao, Hu Yihui, Kong Fanzhi, Miao Yongui   

  • Online:1983-01-10 Published:1983-01-10
  • Contact: Kong Lingshao

Abstract: Wanshan mercury’ mine region belongs to subtropical climate. By the analysis of mercury (Hg) concentration of soil, it shows that the mercury content has a significant variation. Hg concentration in the upper layer of soil is 2.33–420 mg/kg, but in lower layer is 2.03–27l mg/kg. As a result of long-period mining operations, the original vegetation had been destroyed and secondary vegetations were being formed. The grassland with scattered shrubs and shrubs are dominant vegetations in the mine region. The Hg concentration of main plants in 20 sample plots was analysed. It demonstrated the Hg concentration of the plants is different in various species; but the arrangemental positions of same species are similar in different sample plots. When the Hg concentration in the plants is less than 1.50 mg/kg, they are weak accumulator of Hg the plants of Hg concentration in range of 1.50 –3.50 mg/kg are intermedia accumulator of Hg; and Hg concentration is greater than 3.50 mg/kg those are the strong accumulator of Hg. Analysis demonstrated that Hg concentration of leaves is greater than that of branch in all wood-plants, then ratio of Hg concentration between leaves and branches is different in various species. The investigative data indicated that Hg concentration of all plants has largely increased under the condition of higher Hg level in air. Analysis manifested that some plants, such as Dendranthema indicum, Lespedeza davidii and Lindera flauca, in the Hg mine area have comparatively strong ability of absorbed and accumulated gaseous Hg, therefore, they may be used for purifying pollutant of Hg in air. The soil of farmland in the mining area contained very high Hg, as a result Hg concentrations of graincrop, vegetable and farm weeds were increased. It also clearly showed that the Hg concentration in rice was higher than that in the other graincrop; Hg concentration of vegetable in water farmland is richer than in dry farmland; Hg concentration of Polygonum hydropiper is the highest in farm weeds. The Hg amounts in non-edible part are much higher than in the edible part of the plants. The relations between the accumulation of Hg in plant community and the environmental factors are analysed. We found the accumulated Hg concentration of grass-plant and some shrubs are related to organic matter amount in lower layer of soil and the direction of slope. The Hg concentration in old branch was controlled by Hg content of lower layer soil and affected by soil moisture.