短期镉和铬对牵牛花根际土壤线虫群落的影响  

Short-term effects of cadmium and chromium on soil nematode communities around morning glory rhizosphere

作　　者：吕莹 侯辰侠 张琼 侯明志 蒋昊 薛伟锋 LYU Ying;HOU Chenxia;ZHANG Qiong;HOU Mingzhi;JIANG Hao;XUE Weifeng(China Certification and Inspection Group Liaoning Co.Ltd.,Dalian 116039,China;Technology Center of Dalian Customs,Dalian 116000,China;Dalian Customs,Dalian 116000,China)

机构地区：[1]中国检验认证集团辽宁有限公司,辽宁大连116039 [2]大连海关技术中心,辽宁大连116000 [3]大连海关,辽宁大连116000

出　　处：《环境保护科学》2022年第1期101-107,共7页Environmental Protection Science

基　　金：辽宁省自然科学基金面上项目(20170540025);辽宁省博士启动基金项目(2019-BS-008)。

摘　　要：土壤线虫处于土壤食物网中心位置,常被用来评价重金属污染。在土壤中添加不同浓度的镉和铬,用牵牛花作为修复植物,用线虫群落来评价修复后的土壤环境。结果显示,经过90 d修复后,重金属被吸收了小部分,超过80%的重金属留在土壤中给土壤生态带来毒副作用。镉(Cd)和铬(Cr)都降低了土壤pH值、土壤线虫的数量和多样性。镉的添加增加了植物寄生线虫的比例,铬的添加增加了c-p值为1的线虫比例。在镉(20 mg/kg)和铬(50 mg/kg)中间浓度下,线虫数量和多样性均大于低浓度和高浓度。结构方程模型显示,重金属能够直接影响整个线虫群落,也可以通过土壤pH、植物根及捕食关系间接对线虫产生影响。线虫成熟度指数(MI)、结构指数(SI)和富集指数(EI)在污染土壤中变化不大,表明线虫的组成结构比一些指数更适合用来指示短期重金属的污染。重金属改变了土壤理化性质,从而影响了线虫的营养类群结构和生活史策略类群组成,今后还需要更深入的关于线虫群落组成及与环境污染之间关系的研究。Nematodes occupy the key position in soil food webs, and have always been used to indicate the soil heavy metal pollution. Different concentrations of Cadmium(Cd) and Chromium(Cr) were added in soil, the Morning glories(Pharhiris nil) as heavy metal accumulators were planted, the restored soil environment was represented by the soil nematodes. Only a fraction of heavy metals was absorbed after 90 days, which meant the most part(more than 80%) remained in soil and still presented adverse effects on the soil ecology. The application of heavy metals decreased the soil pH, nematode abundance and diversity. Cd increased the proportion of plant parasites, Cr increased the proportion of c-p 1 group. The nematode abundance and diversity were higher at Cd-20(mg/kg) and Cr-50(mg/kg) than other concentrations. Structural equation model showed that heavy metals could affect nematode communities directly and indirectly through soil pH, root weight and predation. Nematode maturity index(MI), structural index(SI) and enrichment index(EI) varied slightly throughout the whole experiment. These results indicated that nematode assemblage and composition were better indicators to short-term heavy metal effects than some common indicators. Heavy metals changed soil physical-chemical properties, and had marked effects on the nematode feeding type and life-history strategies composition. A further assemblage analysis was needed about the relationship between the nematode and the environment pollution.

关 键 词：重金属 牵牛花 土壤线虫 营养类群 生活史策略类群 

分 类 号：X523[环境科学与工程—环境工程]