【作者】 谢荣秀；

【导师】 田大伦； 方晰；

【作者基本信息】 中南林学院 ， 生态学， 2005， 硕士

【摘要】 矿产资源开发和利用而形成的矿业废弃地所带来的一系列生态、社会及经济等问题己成为环境与发展的焦点。本研究从土壤生态学和恢复生态学的角度评价了矿渣废弃地退化生态系统土壤的特征;并再比较恢复植被根系旁的土壤与未经人工改良的矿渣废弃地的土壤理化性质的差异、恢复植被与无重金属污染的植被吸收重金属含量差异的基础上,探讨植被恢复对土壤改良效果及其对重金属富集情况,得出以下结论。 通过对湘潭锰矿矿渣废弃地土壤样品进行分析,该矿渣废弃地土壤的基本理化性质如下:(1) 矿渣废弃地土壤以少石质粗砂土为主。(2) 矿渣废弃地土壤自然含水量、土壤密度和孔隙度分别为:17.79%、1.44g/cm~3、45.24%。(3) pH值为7.49,土壤呈中性,矿渣废弃地土壤有机质、N、P、K、Ca和Mg的平均含量分别为(g/kg):、18.68、1.37、1.01、4.41、14.97和3.79。(4) 矿渣废弃地土壤的Mn、Cu、Pb、Cd、Zn、Ni的平均含量分别为(mg/kg):77990.21、66.38、401.15、640.32、13.15和91.33,大小排序为:Mn>Zn>Pb>Ni>Cu>Cd。矿渣废弃地土壤Mn、Cu、Cd、Ni、Zn、Pb的平均含量比对照地高出18.59、1.32、4.10、4.66、4.44和3.16倍。 通过土壤资源评价,植被恢复之前矿渣废弃地的土壤肥力综合指数为8,对照有林地的为12。限制矿渣废弃地土壤肥力的主要因子是土壤的机械组成和土壤养分。用三种不同的背景值对废弃地土壤重金属污染程度的评价结果是一致的,6种重金属元素的单项污染指数均大于2,表示被污染,其中以Mn、Pb、Cd污染最为严重;6种重金属元素的综合污染指数均大于3,达5级,为重污染。因此在进行植被恢复时,进行土壤基质改良,改善土壤结构,同时添加营养物质和选择对重金属具有耐性和富集能力的植物进行生态恢复。 恢复植被根系旁(恢复植被栾树和杜英根系旁的土壤)的土壤密度和土壤孔隙度与矿渣废弃地(植被恢复过程中未经人工改良的矿渣废弃地土壤)和对照地(邻近非矿区废弃地杉木林林地土壤)存在显著差异,说明人工松土措施降低了土壤密度,增加了土壤孔隙度,改善了土壤结构;矿渣废弃地和恢复植被根系旁的土壤pH值、N、P和Ca的平均含量与对照地差异显著,而恢复植被根系旁土壤的各指标的含量与矿渣废弃地差异均不显著,说明植被恢复时间短,对土壤的化学性质改善不明显;土壤中各重金属元素的平均含量大小排序规律一致,都是矿渣废弃地>恢复植被根系旁>对照地,除Cu和Ni外,恢复植被根系旁和对照地土壤中的Mn、Pb、zn、Cd的平均含量与矿渣废弃地均存在显著差异。说明进行植被恢复和土壤基质改良后,恢复植更多还原

【Abstract】 A series of ecology, society and economy issues from the discards of mine developing and utilizing has already become the focus of environment and development. According to the angle of soil ecology and restoration ecology, the characteristics of degeneration ecosystem on the slag wastelands have described. And then, the difference of soil physical and chemical properties between soil in the vicinity of root of re-vegetation and the slag wasteland are compared. More over the difference on accumulating amount of heavy metals between re-vegetation and the tree without polluted was studied too. The main results of research are as follows:The soil characteristic was investigated and analyzed in the slag wasteland of Xiangtan Manganese Mine. The basic physical and chemical properties of the tailing wastelands were as following: (1) The soil texture in the slag wasteland is mainly sandy soil with a little stone. (2)The soil moisture , soil bulk density and total capillary of slag wasteland is 17.79%、1.44g/cm~3、 45.24% respectively. (3) Soil pH is 7.49 in the slag wasteland. The average contents (g/kg) of organic matter, total N, total P, total K, total Ca and total Mg in the slag wasteland are 18.683, 1.37, 1.01, 4.41, 14.97 and 3.79 respectively. (4)The average contents (mg/kg) of Mn, Cu, Pb, Zn ,Cd, Ni in soil collected from the slag wasteland of Xiangtan Manganese Mine are 77990.21、66.38、 401.15、 640.32、 13.15 and 91.33 respectively. The average contents of heavy metals in soil collected from the slag wasteland in the following order: Mn>Zn>Pb>Ni>Cu>Cd. The content of Mn, Cu, Pb, Zn ,Cd and Ni are 18.59、1.32、4.10、 4.66、 4.44 and 3.16 times of the contrasting area respectively.Before the re-vegetation, the soil fertility composite index of slag wasteland is 8 and the contrasting area is 12 by assessment on the soil resource. The main factors that influence the soil fertility are soil disposition and soil nutrient. Individual event pollution index of 6 kinds of heavy metals by three different background values are all greater than 2, which shows the soil has been contaminated, and Mn, Pb, Cd are the most serious among these heavy metals. And the comprehensive pollution index are all greater than 3, which shows the pollution grade of the soil reaches five grade heavy pollution. So soilamelioration and the selection of tolerant species are applied in the process of the re-vegetationConcerned on the soil density.and soil total capillary, there are remarkable difference between soil in the vicinity of root of re-vegetation and contrasting area and slag wasteland. It indicated that loosen the soil has reduced the soil density, increased the soil total capillary and improved the soil structure. The difference of soil PH value and the average content of N, P, Ca between slag wasteland and contrasting ground is remarkable, but it is not remarkable between slag wasteland and soil in the vicinity of root of re-vegetation. It proved that the soil chemical properties can not be improved obviously in a short time, the metallic content of different soil has the same order: the slag wasteland >soil in the vicinity of root of re-vegetation > contrasting area .Besides Cu and Ni, the average content of Mn, Pb, Zn and Cd in the vicinity of root of re-vegetation and contrasting area is remarkable different from slag wasteland. The results show that after re-vegetation and soil amelioration, the average content of soil heavy metals in the vicinity of root of re-vegetation fall to some extent.Based on the comparison of soil physical and chemical properties of the same kind of re-vegetation {Koelreuteria paniculata and Elaeocarpus decipiens), there is not marked difference in soil physical properties, soil nutrient and content of soil heavy metals between survival and dead vegetation in the vicinity of root of the same kind of re-vegetation. The results shows that the reason why re-vegetation died is unconnected with soil, maybe relate to the plant itself or some other reasons.The soil on the re-vegetation growing better and worse was investigated. The results show that the growing-state of re-vegetation relates to the content of soil heavy metals, but unconnected with soil structure and soil fertility.It is indicated that Koelreuteria paniculata accumulates Mn, Elaeocarpus decipiens accumulates Pb and Zn.更多还原