CAS Workshop on Ecosystem Succession Theory and Practice of Ecological Restoration

五种豆科植物对铜尾矿基质的适应性研究

 田胜尼¹  彭少麟¹  刘登义²  夏汉平¹

（¹中国科学院华南植物研究所，广州 510650；²安徽师范大学生命科学学院，芜湖 241000）

 摘要：尾矿（mine tailings）属于矿业废弃地的一种，它是矿石经粉碎提取精矿、中矿后留下的固体废弃物。尾矿不仅占用大量土地，覆盖原有的植被，破坏生态系统，而且给周边地区带来严重的环境污染。植被恢复是尾矿复垦和治理的最有效的方式，恢复的关键在于物种的选择和基质的改良。豆科植物因具有天然的固氮能力及较强的耐性，应作为尾矿复垦的优先选择的对象。安徽铜陵是我国重要产铜区之一，开采历史悠久，每年排放的铜尾矿近3000万t，目前停止排放的大型尾矿库有铜官山尾矿库、狮子山尾矿库、凤凰山尾矿库、五公里尾矿场和黑沙河尾矿库，占地约1000hm²，另有一些小型的尾矿库和正在排放的大尾矿库。这些堆放的尾矿，由于特殊的理化性质，不仅景观丑陋，寸草不生，而且对周边地区的居民造成严重的环境污染，群众叫苦不迭。针对铜陵市铜尾矿废弃地的复垦，选用了5种豆植物在5种不同的改良方式上进行盆栽复垦试验。5种供试物种为：大豆(Glycine max)、赤豆(Phaseolus angularis)、赤小豆(P. calcaratus)、绿豆(P. radiatus)、山绿豆(P. mininus)。大豆、赤豆、绿豆为乡土栽培植物，赤小豆、山绿豆采集于一铁矿废弃地的野生种群。盆栽基质是以尾矿与土壤按100∶0、75∶25、50∶50、25∶75、0∶100比例（体积比）混合而成，分别标记为：TA100、TA75、TA50、TA25、TA00。研究结果发现，极端贫瘠的基质（有机质3.49g/kg、全P 4.29kg/kg、速效P 3.21mg/kg、全K 2.15mg/kg、速效K 13.33mg/kg）和高含量的Cu（1372.27mg/kg）是抑制植物生长定居的主要因素；5种豆科植物在5种改良方式上均可以萌发，但在混合基质中，尾矿所占的比例越高，种子萌发越晚，但后来基本相当；从生长期内的各物种成活的变化情况来看，大豆、赤豆、赤小豆在各基质中无明显的死亡现象，绿豆和山绿豆在尾矿所占比例高的基质中出现明显死亡现象，尾矿所占比例越高，死亡越明显；全尾矿基质上各种植物的株高、叶绿素和生物量比同期其它组要低或小。通过方差分析和T—检验结果发现，不同的尾矿改良方式对豆科植物的株高、叶绿素和生物量等指标存在着显著或极显著的差异。综合各项指标来看，5种豆科植物中，大豆和赤小豆较其它3种植物具有较强的耐性和适应性，可选用作为尾矿的复垦；TA75的改良方式比较合理，在实践中可采用，经济有效，操作简单。

关键词：铜尾矿；复垦；基质改良；豆科植物

Studies on the adaptation of five legume species to the copper tailings

 Tian Shengni¹  Peng Shaolin¹  Liu Dengyi²  Xia Hanping¹

(¹South China Institute of Botany, Chinese Academy of Sciences, Guangzhou 510650, China; ²School of Life Science, Anhui Normal University, Wuhu 241000, China)

 Abstract: Mine tailings, belonging to one of mine abandoned lands, is a solid waste materials produced by the mining industry after ores are broken to extract fine and normal metals. It not only occupies a mass of field lands, covers the original vegetation, destroys the ecosystem, but also pollutes the environment of adjacent areas. Revegetation is the best approach for the tailings reclamation. The key factors of successful reclamation depend on the selection of species and amelioration of substrates. Because of the natural nitrogen-fixing ability and endurance to adverse conditions, legumes are regarded as one of the most suitable species for mine tailings restoration. Tongling, Anhui Province is one of an important area where copper metal has been explored for a long history in China. About 30 million tons of copper tailings are discharged every year in this region. At present, some large tailings ponds, including Tongguanshan, Shizishan, Fenghuangshang, Five KM, and Heishahe, which cover an area of 1000 hm², have ceased to discharge wastes. In addition to these, there are some small tailings and other discharging large ponds. Very few plants could grow and colonize in these tailings due to their particular physio-chemical properties. People nearby suffered from it due to its toxicity to the heath of man and animals. A pot experiment of five legumes species were conducted on the five different amendment substrates sampled from a waste Cu tailings in Tongling City. The five tested species are Glycine max, Phaseolus angularis, P. calcaratus, P. radiatus, P. mininus. Among them, G. max, P. angularis, P. radiatus are the local legume species; the seeds of P. Calcaratus and P. mininus were picked up from the natural population in an iron-mined abandon land nearby. The five substrates were mixed with the Cu tailings and normal soil with the ratios (in volume) of 100:0, 75:25, 50:50, 25:75, 0:100, respectively, which were marked with TA100, TA75, TA50, TA25, TA00. The result showed that the extremely poor substrate (organic matter 3.49g/kg, total P 4.29g/kg, available P 3.21mg/kg, total K 2.15mg/kg, available K 1.33mg/kg) and high concentration of Cu (1372.27mg/kg ) were the main factors restricting the growth and colonization of plants. The seeds of every species could germinate in the pot, but the higher the substrate proportion accounted for, the later the seeds germinated, but final germination ratios were nearly same for the five species in every same substrate. During the growing period, G. max, P. angularis and P. Calcaratus kept almost all seedlings alive all the time, but many seedlings of P. radiatus and P. mininus died, especially in the higher proportion of tailings. The height, chlorophyll content and biomass of five legumes in the complete tailings substrate were smaller or lower than those in the mixed substrates. According to the results of variance analysis and T-test, the significant or extremely significant differences existed among the five species with special reference to height, chlorophyll content, biomass, and other measured data. Considering from various biological data of the five legumes, G. max and P. calcaratus were better species for Cu tailings reclamation than the other three species because of their better adaptive and resistant characteristics; The TA75 amendment approach was the best for the tailings reclamation due to lower cost and easy operation in practice.

Key words: copper tailings; reclamation; substrates amelioration; legume species

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