不同碳氮磷源改良剂对铅锌尾矿废弃地土壤微生物群落结构的影响

Effects of amendments with different C/N/P ratios on the microbial community structure in Pb-Zn mine tailings

为分析土壤微生物群落结构对退化生态系统恢复过程的价值,开展野外田间实验,添加不同碳氮磷源改良剂对铅锌尾矿废弃地进行生态恢复,研究其对土壤微生物群落结构的影响。结果表明:与对照相比,添加碳氮磷源改良剂显著提高了土壤微生物OTU数,微生物多样性指数(Chao1、ACE、Simpson、Shannon),微生物活性和微生物生物量。与对照相比,添加碳氮磷源改良剂显著改变了土壤微生物群落组成,相对丰度增加的微生物门有Bacteroidetes、Euryarchaeota、Verrucomicrobia、Acidobacteria和Candidate_division_OD1,相对丰度增加的微生物属有Solitalea、Sphingomonas、Blastocatella、Planctomyces、Opitutus、Ohtaekwangia和Gemmata;相对丰度降低的微生物门是Cyanobacteria,相对丰度降低的微生物属是Gaiella。Pearson相关性分析表明:在门水平上,Bacteroidetes、Planctomycetes、Euryarchaeota、Verrucomicrobia与微生物活性、微生物生物量呈显著正相关,Chloroflexi、Cyanobacteria与微生物活性、微生物生物量呈显著负相关;在属水平上,Solitalea、Opitutus、Blastocatella、Ohtaekwangia与微生物活性、微生物生物量呈显著正相关;Gaiella与微生物活性、微生物生物量呈极显著负相关。聚合促进树分析表明:在门水平上,尾矿(CK)、尾矿+尿素(N)、尾矿+中药渣+尿素(MHR+N)处理聚在一起,尾矿+磷肥(P)、尾矿+中药渣(MHR)、尾矿+中药渣+磷肥(MHR+P)和尾矿+中药渣+尿素+磷肥(MHR+N+P)处理聚在一起;在属水平上,CK单列,N、P、MHR、MHR+N、MHR+P和MHR+N+P处理聚在一起。综合分析表明,添加不同碳氮磷源改良剂对土壤微生物群落组成、多样性、微生物活性和微生物生物量均有显著性影响,其中MHR+P和MHR+N+P处理效果最好。

As an important component of the soil ecosystem, soil microorganisms play a key role in the ecological restoration of mining wastelands. Analyses of the soil microbial communities in these areas will provide valuable information for understanding the restoration processes of these degraded ecosystems. A field test was carried out to restore the ecosystem using amendments with different C/N/P ratios and subsequently evaluate the effects of these amendments on the soil microbial community in an abandoned Pb-Zn mine tailings. We obtained the following results:Compared to the control, the use of amendments with different C/N/P ratios significantly increased the operational taxonomic units(OTUs), microbial diversity(measured using the Chao1, ACE, and Simpson′s and Shannon′s indices), microbial activity and microbial biomass. The soil microbial community structure changed significantly when amendments with different C/N/P ratios were used, in comparison to the control. Among the top 10 dominant phyla, the relative abundance of the phyla Bacteroidetes, Euryarchaeota, Verrucomicrobia, Acidobacteria and Candidate division OD1 increased, and the relative abundance of the phylum Cyanobacteria decreased. Similarly, among the top 10 abundant genera, the relative abundance of the genera Solitalea, Sphingomonas, Blastocatella, Planctomyces, Opitutus, Ohtaekwangia and Gemmata increased, and the relative abundance of the genus Gaiella decreased. An analysis of the Pearson′s correlation coefficients showed that, at the phylum level, the phyla Bacteroidetes, Planctomycetes, Euryarchaeota and Verrucomicrobia were positively correlated with microbial activity and biomass, while the phyla Chloroflexi and Cyanobacteria were negatively correlated with microbial activity and biomass. At the genus level, a significant positive correlation was observed between the genera Solitalea,Opitutus, Blastocatella and Ohtaekwangia and microbial activity and biomass, while a significant negative correlation was observed between the genus Gaiella and microbial activity and biomass. An aggregated boosted tree(ABT)analysis revealed that, at the phylum level, the CK, N and MHR+N samples were clustered together, while the P, MHR, MHR+P and MHR+N+P samples formed a close cluster. At the genus level, the N, P, MHR, MHR+N, MHR+P and MHR+N+P samples were clustered together, while CK formed a separate cluster. In conclusion, all the results indicate that amendments with different C/N/P ratios significantly affect the soil microbial community structure, diversity, activity and biomass, and the amendments MHR+P and MHR+N+P are the most effective.