| To investigate the characteristics of heavy metal contents of plant in karst forest, six kinds of elements in
the leaves of endemic plants in Maolan Karst forest were measured. The results showed that the contents of Fe and Mn
were more than 100 mg/kg, Zn and Pb contents varied between 10 and 100 mg/kg, Cd and Ni contents were lower than 10
mg/kg. According to division standards of Bowen H J M and Etherington J R, the contents of Pb, Cd, Fe, Mn and Zn
reached and even more than the poisoning level of plants, plants had the potential risk of heavy metal poisoning. But
except for Pb, the heavy metal contents of all elements were within the scope of the average level of land vascular plants in the world. The elements including Cd, Pb, Mn and Zn showed positive skew distribution, while the elements including Fe
and Ni showed negative skew distribution. There were differences on the different kinds of plants absorption models of
heavy metal elements. The ratio of maximum contents and minimum contents of heavy metal and the coefficients of
variation (CV) values both showed Mn>Cd>Pb>Zn>Fe>Ni. These reflected the heavy metal geochemical distribution
characteristics of the plants in the environment. |
