Species of the Ericaceae or heath family are widely distribute in continental ecosystems and their special ericoid mycorrhizas(ERM)are considered benefi cial to their survival and persistence in variable habitats.Currently,increasing anthropogenic disturbances and improper forest management are aff ecting subtropical forests of China where these native species located.These activities not only aff ect plant communities above-ground,but also impose pressures on microbial communities below-ground.In this study,rootassociated fungal communities of Rhododendron simsii in four forest types under diff erent anthropogenic disturbances were identifi ed using an Illumina Miseq platform,i.e.,old growth forests,secondary forests with one cutting(SECⅠ),secondary forests with two cuttings(SECⅡ),and Chinesefi r plantations(PLF).Intra-and inter-annual variations were analyzed by comparing samples taken in diff erent seasons and years.The results show that:(1)over 1000 OTUs were found in hair roots with most from the division Ascomycota and Basidiomycota belonging to diff erent functional groups;(2)while there were a few indicator OTUs specifi c to diff erent forest types,seasons and years,the proportion of shared taxa was quite large,accounting for 44.9–79.4%of the total OTUs;(3)signifi cantly positive correlations were found between disturbance sensitivity and temporal variations in common fungal orders,and both in major fungal orders were signifi cantly diff erent among fungal functional groups in which putative and possible ERM fungi were highly resistant to disturbances and low temporal variations.The high disturbance resistance and temporal persistence of putative ERM fungi may be essential for the successful adaptation of R.simsii in disturbed subtropical forests of China.
Yanhua ZhangFangping TangJian NiLijia DongLifu Sun
Aims Ericaceous plant species can host diverse fungi in their roots,including ericoid mycorrhizal fungi(ERMF),endophytes,pathogens and some species with unknown functions.However,how this diversity of fungi responds to different human disturbances is not well understood.Methods In this study,we examined the effects of different human disturbance on fungal diversity in hair roots of Vaccinium mandarinorum,an ericaceous plant.Fungal DNA was extracted from hair roots of V.mandarinorum and high-throughput sequencing was applied to detect the diversity of root-associated fungi along a human disturbance gradient in subtropical forests in Gutianshan National Nature Reserve(GNNR)in East China.The four forest types with different disturbance regime were:old growth forest(OGF),secondary forest with once cut(SEC I),secondary forest with twice cut(SEC II)and Cunninghamia lanceolata plantation(PLF).Important Findings The results showed that:(i)diverse fungal operational units(OTUs)were detected in hair roots of V.mandarinorum in the four types of forests,covering fungal phyla of Ascomycota,Basidiomycota,Chytridiomycota,Glomeromycota and Zygomycota;(ii)Community composition of root-associated fungi of V.mandarinorum in PLF was distinct from those in the other three forest types,and two types of secondary forests had similar fungal community composition;(iii)Different fungal families respond differently to human disturbances:fungal families with significant preference to OGF were ectomycorrhizal or saprophytic fungi while fungal families with higher relative abundance in PLF were plant pathogenic or saprophytic fungi;(iv)The first principal component(PC1)of plant community had a significant effect on composition of root-associated fungal community,while edaphic parameters showed no significant effect on fungal community composition in roots of V.mandarinorum.Our results help to better understand the responses of both ericaceous plants and their fungal partners to human disturbances and forest managements.
