植物多样性和土壤改良剂对铅锌矿废弃地土壤微生物群落的影响

Plant diversity and soil amendments affect the soil microbial community in lead-zinc mine wasteland

摘要:

目的 探究植物多样性和土壤改良对铅锌矿废弃地土壤微生物群落的影响。方法 以9种矿区生态恢复常用植物为研究对象，设置不同植物多样性水平(S1-S5)，每种植物多样性水平下均设置对照组(Y：不添加改良剂)和改良组(G：添加有机肥和聚丙烯酰胺)开展盆栽试验，研究植物多样性和土壤改良对土壤微生物群落的影响。结果 改良组植物株高普遍高于对照组；土壤改良后碱解氮、速效磷和速效钾含量均明显升高；而重金属Cd、Pb含量在物种丰富度为9 (S5)时降幅最大，分别下降37.20%和14.85%。土壤微生物多样性随植物多样性的增加而提高；改良剂对真菌群落的丰富度及多样性具有抑制作用，对细菌群落的丰富度与多样性具有促进作用。改良组中土壤真菌群落的丰度在GS4配置时达到最高，其中Observed指数和Chao1指数分别为110.50、169.23；细菌群落丰度在GS2时达到最高，其中Observed指数和Chao1指数分别为1 081.59、1 116.79。在真菌群落中，子囊菌在门和属2个分类学水平上改良组较对照组丰度均有不同程度升高，且子囊菌门的丰度随植物多样性的增加而提高；土壤改良后降低了毛霉菌门和根霉属的丰度，但增加了粪壳菌在属分类学水平上的丰度，且随着植物多样性升高，毛霉菌和根霉菌的丰度会降低。在细菌群落中，土壤改良后增加了鞘氨醇单胞菌和出芽单胞菌在属水平上的丰度。结论 土壤微生物多样性随植物多样性的增加而提高，土壤改良剂的施加抑制土壤真菌群落丰富度和多样性，促进细菌群落丰富度与多样性；随着植物多样性水平的提高，子囊菌门的丰度提高，毛霉菌门和根霉属的丰度降低。

Abstract:

Objective To explore the effects of plant diversity and soil improvement on the soil microbial community in abandoned lead-zinc mine wasteland.Methods A pot experiment was conducted with nine commonly used plants for ecological restoration in mining areas. Different plant diversity levels (S1 to S5) were set up, and for each level, a control group (Y: without soil amendment) and an improvement group (G: with organic fertilizer and polyacrylamide) were established.Results The plant height of the improvement group was generally higher than that of the control group. After soil improvement, the content of available nitrogen, available phosphorus, and available potassium all significantly increased, while that of heavy metals Cd and Pb decreased the most when the species richness was 9 (S5), dropping by 37.20% and 14.85% respectively. The diversity of soil microorganisms increased with the increase in plant diversity. The application of soil amendments reduced the richness and diversity of the fungal community, while enhancing the richness and diversity of the bacterial community. In the improvement group, the soil fungal abundance reached the highest level when GS4 configuration was adopted, with the Observed index and Chao1 index being 110.50 and 169.23, respectively. The soil bacterial abundance reached the highest level when GS2 was adopted, with the Observed index and Chao1 index being 1 081.59 and 1 116.79, respectively. In the fungal community, the abundance of ascomycetes at both the phylum and genus levels increased to varying degrees in the improvement group compared with the control group, and the abundance of Ascomycota increased with the increase in plant diversity. Soil improvement reduced the abundance of Mucoromycota and Rhizopus, but increased the abundance of Sordaria. Moreover, the abundance of Mucoromycota and Rhizopus decreased with the increase in plant diversity. In the bacterial community, soil improvement increased the abundance of Sphingomonas and Gemmatimonas.Conclusion Soil microbial diversity increases as the plant diversity increases. The application of soil amendments reduces the richness and diversity of soil fungi and improves the richness and diversity of soil bacteria. As the plant diversity increases, the abundance of Ascomycota increases, while that of Mucoromycota and Rhizopus decreases.