覆盖对城市裸露土壤真菌多样性及群落结构的影响

Effects of mulching on fungal diversity and community structure in urban exposed soil

【目的】本试验旨在探究不同覆盖材料对土壤真菌多样性及群落结构的影响。【方法】通过控制试验,运用Illumina MiSeq高通量测序技术对以脲醛树脂为胶黏剂制备的有机覆盖垫(NQ)、有机覆盖物(Y)、树皮(S)、木片(M)、鹅卵石(E)、陶粒(T)覆盖和无覆盖(CK)6种覆盖材料下的土壤真菌群落进行测定,并对其进行多样性和群落结构的分析。【结果】6种覆盖材料中,树皮处理下的土壤真菌群落的物种多样性和丰富度最高,以脲醛树脂为胶黏剂制备的有机覆盖垫处理下的土壤真菌多样性和丰富度最低。不同覆盖处理的土壤中,真菌物种和优势物种存在差异。在门水平上,子囊菌门为最优势菌门,相对丰度为70.84%~86.86%,远远大于次优势的担子菌门(相对丰度为3.27%~12.78%)。在属水平上,有机覆盖垫、鹅卵石、陶粒、树皮以及无覆盖处理中g_unclassified_o_Hypocreales为最优势属,在木片覆盖处理中,最优势属为毛壳菌属,在园林绿化废弃物覆盖处理中g_unclassified_o_Eurotiales为最优势属。相关性分析结果显示,土壤速效磷含量与土壤真菌多样性呈极显著负相关(P<0.01),与土壤真菌丰富度呈显著负相关(P<0.05);土壤有机质含量与土壤真菌多样性呈显著负相关(P<0.05),与土壤真菌丰富度呈极显著负相关(P<0.01)。毛壳菌属、g_norank_p_Mucoromycota、g_unclassified_f_Pyronemataceae、镰刀菌属受环境因子影响较大。【结论】覆盖措施能够影响土壤真菌多样性和丰富度以及群落结构,不同覆盖材料对土壤真菌群落的物种多样性和丰富度以及群落结构影响不同。土壤速效磷、有机质含量是影响土壤真菌多样性和丰富度的重要因素,不同物种对于环境因子的响应也存在差异。本研究设置的6种覆盖材料中,使用树皮作为覆盖物处理下的土壤真菌多样性和丰富度最高。

[Objective]The purpose of this experiment was to explore the effects of different mulching materials on soil fungal diversity and community structure.[Method]Through controlled experiments,the Illumina MiSeq high-throughput sequencing technology was used to determine the soil fungal communities under organic mulch mat prepared with urea-formaldehyde resin as adhesive(NQ),organic mulch(Y),bark(S),wood chips(M),pebbles(E),pottery(T)and non-mulch(CK),and to analyze their diversity and community structure.[Result]Among the 6 mulch materials,the species diversity and richness of soil fungal communities were the highest under S treatment and the lowest under NQ treatment.There were differences in fungal species and dominant species in soil under different mulching treatments.At the phylum level,Ascomycetes was the most dominant phylum,with a relative abundance of 70.84%to 86.86%,which was much higher than Basidiomycetes(relative abundance of 3.27%to 12.78%).At the level of genus,in the NQ,E,T,S,and CK treatments,the most dominant genus was g_unclassified_o_Hypocreales;in M treatment,the most dominant genus was Chaetomium;and in Y treatment,the most dominant genus was g_unclassified_o_Eurotiales.The results of correlation analysis showed that the content of soil available phosphorus was highly significantly negatively correlated with the diversity of soil fungi(P<0.01)and significantly negatively correlated with the abundance of soil fungi(P<0.05);the soil organic matter content was negatively correlated with the soil fungal diversity(P<0.05),and highly significantly negatively correlated with the abundance of soil fungi(P<0.01).Chaetomium,g_norank_p_Mucoromycota,g_unclassified_f_Pyronemataceae,and Fusarium were greatly affected by environmental factors.[Conclusion]Mulching measures can affect soil fungal diversity,richness and community structure.Different mulching materials have different effects on the species diversity,richness and community structure of soil fungal community.Soil available phosphorus and organic matter content are important factors affecting soil fungal diversity and richness.Different species also have varied responses to environmental factors.Among the six mulching material set in this study,the soil fungal diversity and richness are the highest under the treatment of bark as mulch.