【作者】 岳庆玲；

【导师】 常庆瑞； 陈同斌； 雷梅；

【作者基本信息】 西北农林科技大学 ， 土壤学， 2004， 硕士

【摘要】 土壤的重金属污染是致使环境遭受破坏的重要因素之一，本文主要以湖南省郴州市柿竹园钨锡铋钼矿区和宝山铅锌银矿区为例，研究了土壤以及其上生长的植被的多种重金属污染状况，旨在探明矿区土壤的污染特性，以及植物对重金属吸收的耐性特征。植被恢复和重建是当前所面临的一个重要环境问题，寻找和发现适合当地气候条件与土壤条件的重金属耐性植物是矿区植被恢复和污染土壤修复的前提。通过对研究区进行系统的采样分析和调查研究，得出以下结论：　 柿竹园矿区范围内，选矿厂土壤砷、镉、铅、锌严重超标，尾矿区也受到不同程度的污染；土壤重金属砷、镉、铅、锌之间呈极显著正相关，相关系数均达到 Ｐ　＞0.01 的显著水平，但是与铜之间不存在明显的相关性。重金属胁迫效应影响着物种分布，选矿厂物种分布较少，尾矿物种相对较多。植物体内重金属表现为铅、锌积累较高，其中蜈蚣草（Pteris vittata）、苎麻（Boehmeria nivea）、败酱（Patrinia scabiosaefolia）、木贼（Equisetum hiemale）等都对重金属表现出较强的耐性。　 宝山矿区，土壤中铅的含量超标甚为严重，最高达 49294 mg·kg-1。在高铅背景下，植物体内含量也受到相应的影响。例如，苎麻、剑叶凤尾蕨、败酱和多头铅锌菊的地上部均超过 1000 mg·kg-1。土壤镉含量也非常高，最高可达 1061 mg·kg-1，堇菜体内的镉含量明显高于其它植物，超过 300 mg·kg-1。相对铅、镉而言，土壤中砷、铜、锌污染较轻，因此，他们在植物体内的吸收和积累也相对不甚明显。　 对于转运系数，柿竹园矿区，苎麻、败酱、石松、三叶草等各重金属元素的 TF 基本上都大于 1，表明这些植物有较强的将重金属从根部向地上部转运的能力。宝山矿区，苎麻、败酱、堇菜、芒草等各重金属元素的 TF 值基本上都大于 1，结合柿竹园的数据，表明苎麻和败酱吸收重金属不因土壤环境的改变而影响其对重金属吸收转运的性能；某些植物具有转运多种重金属的能力，如苎麻和多头铅锌菊等；镉在植物体内转运系数通常都大于 1，表明移动性较强，而铜向地上部转运能力极弱，移动性较差。　 植物体内的重金属含量和土壤中的含量之间的关系比较复杂，某些植物随土壤重金属含量的增加而呈大幅度增加，如蜈蚣草；但某些植物则随土壤重金属含量的增加而增加幅度不大，如木贼。此外，还有的植物随着土壤中重金属浓度的增加，植物中的重金属含量到达某一值时就不再呈明显增加，而是在某一值附近浮动，如败酱。　 通过调查不同植物耐受重金属的能力及其机理有明显的差异，发现蜈蚣草、苎麻、剑叶凤尾蕨、多头铅锌菊、堇菜等属于富集型植物，能够从土壤中主动吸收富集属元素，同时植物地上部重金属含量大于根部含量；败酱、木贼、柳叶黄菊、蟋蟀草等属于指 iii<WP=8>摘　　要　示型植物，具有对土壤中重金属的被动吸收特征，能将重金属吸收至体内，但大量金属元素囤积于根部，只有少量向地上部运移，减少对光合、呼吸、生殖系统的伤害；芒草、三叶草、紫苏、苏铁蕨、地榆、石畺松等属于规避型植物，能抵制植物根系对重金属的吸收，并将土壤重金属的某种化学形态沉淀在根系表面，只有很少量被吸收至体内。更多还原

【Abstract】 Heavy metal soil contaminated in mining is a severe environmental problem, it isimportant to screen for tolerant plants, which is adapt to local climate and soilcondition to remediate heavy metal contaminated soils. In the research of Shu ZhuYuan W-Sn-Bi-Mo mining and Bao Shan Pb-Zn-Ag mining, through systemicsampling analysis and investigation study, the main conclusions are as follows: In SZY, the extent of soil contamination in mining is more severer than those oftailings. The concentration of heavy metal in mining is very high and there isprominently significant correlationship among As、Cd、Pb and Zn in soil, correlationcoefficient >0.85, but no relationship with Cu. The threatening effect affects thedistribution of species, which means that there are few species at Cai Shan mining butmore at other tailings. In bodies of plants, Pb、Zn concentration is very high, Pterisvittata 、Boehmeria nivea and Miscanthus sinensis have strong tolerance to heavymetal. In BS, Pb concentration in soil is severely beyond soil national standard value,the maximum is 49294 mg·kg-1. In high Pb environment, bodies of plantscorrespondingly accumulate Pb, especially, shoots of Boehmeria nivea、Pterisensiformis and Patrinia scabiosaefolia equally exceed 1000 mg·kg-1. Cdconcentration is very high too, the maximum is 1061 mg·kg-1. Shoots of Violabaoshanensis 300 mg·kg-1, notably higher than other plants. Comparatively, As、Cuand Zn concentration have less contamination. Concerning TF, in SZY, Boehmeria nivea、Patrinia scabiosaefolia et al TF isbeyond 1, which shows that these plants have stronger ability transferring heavy metalfrom root to shoot. In BS, Boehmeria nivea、Patrinia scabiosaefolia et al TF isbeyond 1 too, which shows that environment condition has few effect on absorptionand transporting capability of both plants. Besides, Some Plants can transfer severalheavy metals, such as Boehmeria nivea. Cd TF is beyond 1 in a general way, and Cdis easy to move. The other way round, Cu can hardly move in bodies of plants. The relation between plants and soils heavy metals concentration iscorrespondingly complex. Through investigating plants tolerance ability andmechanism difference, heavy metal absorption of plants have three traits:Accumulators (ex: Pteris vittata and Boehmeria nivea), which accumulate heavymetal to body; Indicators(ex: Patrinia scabiosaefolia and Equisetum hiemale), which v<WP=10>Abstractgather heavy metal with root; Excluders(ex: Miscanthus sinensis), which depositheavy metal to root surface. Compared with difference of elements concentration, byand large, Pb and Zn contamination is more severer thanAs、Cd、Cu.更多还原