| Soil microbes are important decomposers of terrestrial ecosystems,and soil fungi is one of the important components in the process of decomposition.Soil fungi is not only an indispensable promoter in processes of biogeochemical cycle and energy flow,but also an indictor in predicting the climate and environment change.Therefore,it is vital to understand the biogeographic distribution pattern of soil fungal diversity.Due to the limited technology,soil fungi has not been deeply studied,until the metagenomics technology developed in recent years,and the studies of soil fungal diversity pattern has been gradually progressing from exploring.The results of spatial distribution pattern were scientifically found,which provided theoretical and practical guidance for revealing mechanisms of ecosystem function change.Shennongjia National Park(SNP),located in Northwest Hubei province of China.SNP bred rich biomass resources which progressed a typical elevation gradient feature.Therefore,it is an ideal region for studying the distribution of biodiversity pattern.Here,soil samples were collected from five different forest types along different elevational gradient(1 000–2 800 m)in SNP,the Illumina Mi Seq sequencing and microbial Geo Chip technology were used to study the soil fungal diversity and their formation mechanisms:(1)The Illumina Mi Seq sequencing was used to study the soil fungal diversity pattern along the elevational gradient and its mechanisms.The results showed that 38.83%,34.76% and 25.86% of soil fungal OTUs were respectively derived from Zygomycota,Basidiomycota and Ascomycota.With the elevation increased,the relative abundance of Zygomycota significantly decreased but Basidiomycota significantly increased,and there was no significant change in Ascomycota.Detrended correspondence analysis(DCA)and dissimilarity test indicated that the soil fungal community structure among five sites were significantly different.The ?-diversity of soil fungi showed a decreasing trend(P < 0.01)as the elevational increasing,which was similar to the trend of plant ?-diversity.And the ?-diversity was significantly increased as elevational distance increasing.The null model revealed that deterministic process dominated the soil fungal community between different vegetation types,but stochastic process dominated in the same vegetation type.Pearson correlation and partial Mantel test indicated that the mean annual temperature and prepetition were the key factors in shaping the soil fungal diversity pattern along elevational gradient.(2)The Illumina Mi Seq sequencing and microbial Geo Chip technologies were used to analyzed the impact on soil fungal community structure and metabolic potential after succession from Evergreen broadleaved(EBF)to deciduous broadleaved(DBF)forests in Shennongjia National Park,China.The results showed that the soil fungal richness was higher,marginally significance(P = 0.079),in DBF than that in EBF,and the fungal functional gene diversity was significantly higher(P < 0.01)in DBF than that in EBF.DCA indicated that the soil fungal communities from each forest type were well separated.Zygomycota was the most dominant phylum in both forest types,however,the most dominant genus was different.Molecular ecological network analysis showed that the interaction and complexity among functional genes were different between EBF and DBF.The relative abundance of many genes related to labile carbon degradation was significantly higher(P < 0.05)after forest succession,and relative abundance of carbon cycling related genes was significantly negatively correlated with the content of soil organic carbon(SOC),dissolved SOC and labile SOC,which may promote C cycling process in DBF.(3)The forest line is the “indicator light” of climate change,the shrubs and coniferous forest were sampled and the soil fungal community structure were studied.The results showed that the dominant soil fungal phyla,genera,and species differed between the two forest types.Basidiomycota was the dominant phylum in the coniferous forest,whereas Zygomycota was dominant in the shrub forest.DCA and dissimilarity test indicated that their soil fungal communities were significantly different,and the soil fungal diversity was significantly higher(P < 0.05)in the coniferous forest than that in the shrub forest according to the Shannon index,Chao value,and richness index.Canonical correlation analysis(CCA)and Mantel test indicated that the soil p H,plant diversity,soil moisture,and temperature had significant linkages with the soil fungal community structure. |
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