物种多样性对铅锌尾矿废弃地植被及土壤的生态效应  

Ecological Effects of Species Diversity on Plant Growth and Physico-Chemical Properties in a Pb-Zn Mine Tailings

作　　者：杨胜香 曹建兵[3] 李凤梅 彭禧柱[2] YANG Sheng-xiang;CAO Jian-bing;LI Feng-mei;PENG Xi-zhu(College of Resources and Environment,Zunyi Normal University,Zunyi 563006,China;College of Biology and Environmental Sciences,Jishou University,Jishou 416000,China;Ecology and Environment Bureau of Xiangxi Tujiazu&Miaozu Autonomous Prefecture,Jishou 416000,China)

机构地区：[1]遵义师范学院资源与环境学院,遵义563006 [2]吉首大学生物资源与环境科学学院,吉首416000 [3]湘西土家族苗族自治州生态环境局,吉首416000

出　　处：《环境科学》2021年第8期3953-3962,共10页Environmental Science

基　　金：国家自然科学基金项目(41967020);贵州省自然科学基金项目(黔科合基础[2019]1322);贵州省教育厅科技拔尖人才计划项目(黔教合KY字[2018]065);遵义师范学院博士启动基金项目(遵师BS[2017]13)。

摘　　要：尾矿库是金属矿山最常见且最难恢复的废弃地.开展野外田间试验,在铅锌尾矿上建立了具有物种多样性梯度(1、4、8和16种)的植被,分析物种多样性对植物群落、重金属迁移和营养元素的影响及其生态效应.结果表明:(1)植物物种多样性提高了尾矿新建植物群落的盖度和生产力.1-物种的植被盖度和生物量平均值分别为33.4%和66.7 g·m^(-2),16-物种的为78.4%和183.8 g·m^(-2),分别增长了2.4倍和2.8倍.(2)植物物种多样性促进了尾矿土壤营养元素的累积.对尾矿营养元素含量随物种多样性的增加进行线性回归发现,随着植物物种多样性的提高,总有机碳(TOC)、水溶性有机碳(SOC)、总氮(TN)和总磷(TP)累积量显著性增加(TOC:r=0.30,P <0.001;SOC:r=0.20,P <0.05;TN:r=0.24,P <0.05;TP:r=0.20,P <0.05).(3)植物物种多样性减少了尾矿重金属有效态含量及重金属在尾矿土壤-植物系统中的迁移和累积.重金属有效态含量随物种多样性的增加显著下降(DTPA-Cd:r=0.20,P <0.05;DTPA-Cu:r=0.19,P <0.05;DTPA-Pb:r=0.23,P <0.05和DTPA-Zn:r=0.23,P <0.05).随着植物物种多样性的提高,植物地上部分重金属(Cd:r=-0.16,P <0.01;Cu:r=-0.23,P<0.001;Pb:r=-0.15,P <0.05和Zn:r=-0.18,P <0.001)的含量是逐渐下降的.综合分析表明,植物物种多样性对尾矿生态恢复具有促进作用.The remediation of metalliferous mine tailings remains a challenge in many regions of the world.A field experiment was conducted on representative Pb-Zn mine tailings with different species richness(1-,4-,8-,and 16-species) to evaluate the potential roles of species diversity in the phytoremediation of metalliferous mine tailings.The main results were(1) high species diversity greatly enhanced vegetation cover and biomass.For example,the average vegetation cover and biomass were 33.4% and 66.7 g·m^(-2) in 1-species plots and reached 78.4% and 183.8 g·m^(-2) in 16-species plots,respectively.(2) Plant species diversity had significant effects on nutrient accumulation.Total organic carbon(TOC),water organic carbon(SOC),total nitrogen(TN) and total phosphorus(TP)significantly increased with the species diversity(TOC: r = 0.30,P < 0.001;SOC: r = 0.20,P < 0.05;TN: r = 0.24,P < 0.05;TP:r = 0.20,P < 0.05) .(3) Species diversity not only reduced the concentration of diethylenetriamine pentaacetate(DTPA)-extracted metals in the mine tailings,but also decreased heavy metal transfer and accumulation in the soil-plant system.With enhanced species diversity,DTPA-extracted Cd,Cu,Pb,and Zn decreased significantly(DTPA-Cd: r = 0.20,P < 0.05;DTPA-Cu: r = 0.19,P <0.05;DTPA-Pb: r = 0.23,P < 0.05;DTPA-Zn: r = 0.23,P < 0.05).With increasing species diversity,a slightly decreasing trend was observed for Cd,Cu,Pb,and Zn concentrations in the aboveground parts of plants(Cd: r =-0.16,P < 0.01;Cu: r =-0.23,P < 0.001;Pb: r =-0.15,P < 0.05;Zn: r =-0.18,P < 0.001).In conclusion,plant diversity can play an important role in mine reclamation.

关 键 词：物种多样性 重金属 尾矿 植被恢复 生态效应 

分 类 号：X171[环境科学与工程—环境科学] X53