铅锌矿区周边农田土壤跳虫群落特征与重金属污染的关联

以云南兰坪铅锌矿区周边的农田为对象,按距矿区距离设四条样带,每个样带按距河流由近至远等距选3个样点进行定量采样,测定和分析土壤跳虫物种多样性和群落结构、土壤重金属含量和理化性质、及跳虫体内的铅含量.共获跳虫26种,平均密度12042 ind·m2.样点与矿区或河流距离增加,土壤中镉、铅和锌含量下降,跳虫体内重金属含量下...

Relationship between community structure of soil Collembola and heavy metal pollution in farmlands around a lead-zinc mining area

[objective] Soil fauna are an important indicator for quality assessment and monitoring of contaminated soils. However, few studies have been reported in the literature in China on community structure of Collembola and variation characteristics of certain specific species in soils contaminated with heavy metals in mining areas. In order to explore relationship between heavy metal pollution in soil and community structure of Collembola, toxic effects of the pollution on collembolan and law of the response of collembolan to the pollution, in an attempt to provide a scientific basis for assessing and monitoring soil quality. [Method] In this paper, on the farmlands around the Lanping lead-zinc mining in Yunnan Province, four sample belts, A, B, C and D were laid out, varying in distance from the mining. Among them, A, B and C were belts of contaminated farmlands and D the one free of contamination as CK. And in each belt, 3 sampling points were arranged at the same intervals along a line vertical to the river running through the belts. Point 1 was the closest to and Point 3 the farthest away from the river. So a total of 12 sampling points were specified for soil sampling, and three soil samples were collected quantitatively from each sampling point for identification and count of collembolan and analysis of soil heavy metals, physicochemical properties and heavy metals in collembolan, separately, and each soil sample was divided into 5 portions as replicate for the analysis of species diversity and community structure of collembolans, heavy metal concentration in their bodies and heavy metal concentration and physicochemical properties of the soils. [Result] A total of 1445 collembolan individuals of 26 species were acquired, belonging to 2 orders, 6 families and 15 genera and reaching 12042 individuals/m2 in average population density. The Collembola community was characterized by apparent dominancy with specific groups and relative deficiency in diveristy. The farther the sample points from the mining or the river, the lower the concentration of Cd, Pb and Zn in the soil, the lower the concentration of heavy metals in the collembolan body, and the higher the species richness (number of species), richness index and abundance of collembolans (density). And responses of the animals were greater to the content of available heavy metals than to the total heavy metals, especially in species richness and heavy metal concentration of collembolans. Onychiurus sp. was negatively related to the content of available Pb in population density. The three species of Isotoma were all negatively related to both total and available Cd. and Isotoma sp.3 was negatively related to total and available Zn. Lepidocyrtus sp. was positively related to total Cd, Pb and Zn. Besides, Onychiurus sp. and Onychiurus folsomi were positively related to soil organic matter. Hypogastrura yosii was positively related to soil pH. Isotoma sp.1 was positively related to soil pH and soil bulk density. [Conclusion] Structure of the Collembola community and distribution of certain species in the farmland system around the lead-zinc mining area were significantly affected by heavy metal pollution: The collembolan community responded greatly to heavy metals in species richness, richness index and abundance, and was more sensitive to available heavy metals than to total ones. So the contents of available heavy metals are good indicators reflecting change in Collembola community. Onychiurus sp., the three species of Isotoma and Lepidocyrtus sp. possess the potential to act as indicator for assessment of heavy metal pollution and so do Onychiurus sp., Onychiurus folsomi and Isotoma sp.1 for assessment of soil quality.