Comparing the fungal community structure in biological soil crusts obtained under different plant communities in a copper mine tailings

Biological soil crusts( BSCs) found on the surface of bare wasteland and beneath the tracheophyte communities in mine tailing ponds,play an important role in the processes that are involved in natural ecological restoration of copper mine tailings. Fungi are an important part of BSCs,and they adhere to the surface soil and other components stably through their fungal hypha. It is important to enhance the resilience of mine tailings against wind erosion,as well as improve their moisture holding capacity that can be beneficial for the plant colonization on loose mine tailings' surfaces. However,the structure and diversity of microbial communities( especially fungal communities) of BSCs on the surface of mine tailings are poorly investigated. In this study,the changes in the fungal diversity and community structure of BSC samples at different successional stages,as well as tracheophyte species,were investigated using molecular biotechnologies. Moss-algal crusts beneath the Hippochaete ramosissimum( YM) had the lowest diversity index( including Shannon-Wiener index,Simpson index and Pielou index),among other significant differences of diversity and evenness that were observed in the fungal communities from the BSC samples and tracheophyte species. In addition,significant differences in basic soil chemical properties,such as loss-on-ignition,total nitrogen,and available phosphorus,were also found among the BSC samples.This indicates that the fungi in the BSC samples included the phyla Ascomycota,Basidiomycota,and Chytridiomycota. The phylum Ascomycota was dominant in these samples,and displayed a higher relative abundance 55. 12% -87. 73%,followed by the phylum Basidiomycota with a relative abundance of 12. 27% -43. 86%. Significant differences in fungal community structure were found at the phylum,order,class,and genus level. In addition,a non-metric multidimensional scaling( NMDS) analysis also showed that the fungal community structure is significantly influenced by tracheophyte species and the successional stage. However,canonical correlation analysis( CCA) indicated that this variation was not mainly caused by the substrate chemical properties of the mine tailings. In addition,Pearson correlations showed no significant correlation between fungal community structure and soil chemical properties.