College of Environmental Science and Engineering, Central South University of Forestry and Technology, Changsha, 410004, China; School of Metallurgy and Environment, Central South University, Changsha, 410083, China.
School of Metallurgy and Environment, Central South University, Changsha, 410083, China.
Chemosphere. 2022 Mar;290:133107. doi: 10.1016/j.chemosphere.2021.133107. Epub 2021 Nov 27.
Tree-herb intercropping is a prospective approach for the ecological remediation of soil contaminated with potentially toxic metals (PTMs). In this study, the facilitation and microbial community response of woody plant Morus alba L. intercropped with Cd/Zn hyperaccumulator Sedum alfredii H. and pioneer plant Arundo donax L. were carried out in the PTM-contaminated soil. The results indicated that the intercropping system can improve M. alba L. growth, as well as increase its PTMs uptake. The dried biomass of M. alba L. in the intercropping system was increased observably (p < 0.05) by 55.1%. Meanwhile, the contents of chlorophyll in M. alba L. leaves, PTMs contents in M. alba L. roots, and the relative abundance of Rhizobiaceae, Singulisphaera, Isosphaeraceae, and Arthrobacter in the M. alba L. rhizosphere were also notably (p < 0.05) enhanced. Meanwhile, the interactions of microorganisms in the intercropped plants rhizosphere might contribute to improving the biological quality of the contaminated soil. Soil sucrase and acid phosphatase activities in the intercropping system were significantly (p < 0.05) increased by 97.03% and 34.91% relative to the control. Furthermore, in the intercropping system, 93.61%, 61.30%, and 79.18% of Cd, Pb, and Zn were extracted by S. alfredii H., 72.16% of Cu was extracted by A. donax L., and 46.38% of Mn was extracted by M. alba L., which indicated that the extraction amounts of PTMs among the intercropped plants were relatively compensated. The results suggested that the tree-herb intercropping might increase the coexistence of plants and facilitate the adaptability for ecological remediation of PTM-contaminated soils.
林-草间作对修复重金属污染土壤具有重要意义。本研究以 Cd/Zn 超积累植物垂穗景天（Sedum alfredii H.）和先锋植物芦竹（Arundo donax L.）与桑树（Morus alba L.）构建林-草间作体系，探讨重金属污染土壤中木本植物桑树的生长及其对重金属的吸收，分析间作系统中桑树的根际微生物群落特征，以及对土壤酶活性和重金属赋存形态的影响。结果表明，间作系统能显著促进桑树的生长，其地上部干生物量增加 55.1%（p < 0.05），叶绿素含量、根系重金属含量以及根际土壤中 Rhizobiaceae、Singulisphaera、Isosphaeraceae 和 Arthrobacter 相对丰度也显著增加（p < 0.05）。间作系统中植物根际微生物的相互作用可能有助于改善污染土壤的生物学质量。间作系统中蔗糖酶和酸性磷酸酶活性分别显著提高了 97.03%和 34.91%（p < 0.05）。此外，在间作系统中，垂穗景天对 Cd、Pb 和 Zn 的提取率分别为 93.61%、61.30%和 79.18%，芦竹对 Cu 的提取率为 72.16%，桑树对 Mn 的提取率为 46.38%，间作植物对重金属的提取量相对得到了补偿。本研究表明，林-草间作可能增加植物共存的可能性，并有助于促进重金属污染土壤的生态修复。
