凡口铅锌尾矿影响植物定居的主要因素分析

Analysis of major constraints on plant colonization at Fankou Pb/Zn mine tallings.

通过温室栽培和野外调查 ,分析了凡口铅锌尾矿影响植物定居的主要因素 .结果表明 ,铅锌尾矿的Pb、Zn、Cu和Cd的总量分别达 3430 0、3650 0、2 1 5和 82 .6mg·kg- 1 ;有效态的Pb、Zn、Cu和Cd分别为 1 .5、1 963、0 .71和 8.0 3mg·kg- 1 .在栽培试验中 ,重金属毒性严重抑制格拉姆柱花草 (Stylosanthesguianensis)根系的活力 ,使得植物无法利用无机养分 ,并可导致明显的白化症状 ,从而严重影响格拉姆柱花草的生长 ,无论在野外或在室内实验条件下 ,有效态Zn和Cd都与植物的生长呈显著负相关 ,重金属毒性 ,尤其是有效态Zn和Cd的毒性是凡口铅锌尾矿影响植物定居的限制因子 .

Through greenhouse cultivation and field investigation, the major constraints on plant colonization at Fankou Pb/Zn mine tailings are analysed.The results show that total Pb, Zn, Cu and Cd contents in the tailings are 34300,36500,215 and 82.6 mg·kg -1 ,while their available contents are 1.5, 1963,0.71 and 8.03 mg·kg -1 respectively.Greenhouse cultivation reveals that the toxicity of heavy metals significantly inhibits the root vitality of Stylosanthes guianensis, prevents plant from absorbing inorganic nutrient, and leads to evident chlorosis, which significantly affects grass growth. Both greenhouse cultivation and field investigation demonstrate that available Zn and Cd contents in tailings are negatively correlated with plant growth.Heavy metal toxicity, especially the toxicity of available Zn and Cd is the major constraint on plant colonization at Fankou Pb/Zn mine tailings, and the extreme infertility is another major constraint on plant growth.