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

  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.