花垣铅锌尾矿废弃地地枇杷斑块不同演替阶段土壤微生物群落变化

Changes of Soil Microbial Community in Ficus tikoua Patch at Different Succession Stages in Huayuan Lead-Zinc Tailings Wasteland

摘要: 本研究以花垣铅锌尾矿废弃地的裸尾矿地为对照CK，地枇杷斑块不同演替阶段(地枇杷斑块Y、地枇杷 + 草本植物斑块M和地枇杷 + 草本 + 木本植物斑块O)为研究对象，测定不同演替阶段地枇杷斑块的土壤理化性质，采用土壤细菌16S rDNA和真菌ITS高通量测序方法分析了不同演替斑块的土壤细菌和真菌群落多样性和结构变化，探讨了细菌和真菌群落结构和多样性与土壤养分的相关性。结果表明：与裸尾矿(CK)相比，随地枇杷斑块演替的正向进行，1) 尾矿的总磷(TP)、有效磷(AP)、总氮(TN)、氨态氮(AN)、有机质(OM)和含水量均显著增加，土壤容重则表现为先增后降；2) 尾矿废弃地土壤细菌和真菌群落多样性逐渐增加，但不同演替阶段之间无显著差异；3) 土壤细菌优势门主要为变形菌门、蓝细菌门、放线菌门、绿弯菌门、酸杆菌门、拟杆菌门、芽单胞菌门、Saccharibacteria、栖热菌门(相对丰度 > 10%)，真菌优势门为子囊菌门和担子菌门，酸杆菌门和变形菌门相对丰度增加，蓝细菌门和疣微菌门相对丰度逐渐降低，子囊菌门虽然呈现先降后升趋势，但不同演替阶段之间并无显著差异。4) Pearson相关性分析表明，细菌群落多样性和真菌群落物种数是影响尾矿土壤养分累积的主要因素，变形菌门尤其是α-变形菌纲以及被孢霉门是尾矿土壤养分累积的关键类群。结论：随着地枇杷斑块的正向演替，尾矿土壤微生物群落结构产生了显著变化，蓝细菌门和疣微菌门相对丰度逐渐降低，变形菌门相对丰度增加，在演替后期产生了新的真菌类群球囊菌门和壶菌门，从而有效地促进了尾矿废弃地土壤养分的累积。本研究结果可进一步为利用地枇杷进行铅锌尾矿废弃地的生态恢复提供实验数据支持。

Abstract: Ficus tikoua patch at different successional stages (Ficus tikoua Bur. patch + Y, Ficus tikoua Bur. + Herbaceous patch M, Ficus tikoua Bur. + herb + Woody plant patch O) were studied as the research object in the present study, while the bare tailings in lead-zinc tailings wasteland in Huayuan County were used as the control. In order to explore the relationship between community structure and diversity of bacteria and fungi and soil nutrient, soil physicochemical properties of Ficus tikoua patch at different successional stages were determined, while also using high-throughput sequencing methods of soil bacterial 16S rDNA and fungal ITS to evaluate the community diversity and structure changes of bacteria and fungi in soil. The findings revealed that: compared with the bare tailings (CK), 1) The total phosphorus (TP), available phosphorus (AP), total nitrogen (TN), ammonia nitrogen (AN), organic matter (OM) and water content of tailings increased over succes-sion, and the soil bulk density increased first and decreased lately. 2) The diversity of bacterial and fungal communities in tailings wasteland increased gradually, while there was no significant difference between different successional stages. 3) Proteobacteria, Cyanobacteria, Actinomycetes, Chloroflexi, Acidobacteria, Bacteroidetes, Gemmatimonadetes, Saccharibacteria and Deinococcus-Thermus (relative abundance > 10%) were the most dominant bacteriophyta, Asco-mycota and Basidiomycota were the most dominant eumycophyta in soils. and Acidobacteria and Proteobacteria increased, Cyanobacteria and Verrucobacteria decreased gradually, while Ascomycetes decreased first and increased lately, relative abundance of dominant phyla was no significant difference at different successional stages. 4) Pearson correlation analysis showed that the nutrient accumulation was mainly affected by the diversity of bacterial community and the species number of fungal community, α-Proteobacteria and Sporinomycetes were the key groups of nutrient accumulation in tailings soil. Thus, along the positive succession of Ficus tikoua patch, significant differences in the tailings soil microbial community structure were observed, and the relative abundance of Cyanobacteria and Verrucobacteria decreased gradually, while Proteobacteria increased. New fungal groups such as Spheroidia and Chytridomycetes were gen-erated later in succession, which effectively promoted the accumulation of soil nutrients in tailings wasteland. Based on this, it can further provide experimental data support for ecological res-toration of lead-zinc tailings wasteland by Ficus tikoua Bur.