Linkage Between Shurb Communities And Soil Arbuscular Mycorrhizal Fungi Communities In Karst Peak-Cluster Depression Area Of Southwest China

Arbuscular Mycorrhizal Fungi(AMF)symbiosis with host plants.In these plant-fugal relationships can promote the absorption of mineral elements such as phosphorus in soil and improve interspecific relationship.Previous studies reported that AMF is a priority choice for vegetation restoration.And vegetation restoration is a priority choice for rock desertification in Southwest Karsts area of China.In the past,more attentions were paid on vegetation restoration(e.g.plant species selection afforestation and regulation of vegetation planting),while less on the role of AMF in soil.Shrub widely distributes in karst regions,and plays an important role in vegetation restoration.In this study,a typical shrub ecosystem(1hm2)in the karst peak-cluster-depression region of northwest Guangxi was selected.Shrub communities were investigated and soil samples in different habitats were collected.High-throughput sequencing technology and other modern molecular biology techniques were used to clarify the temporal and spatial heterogeneity of soil AMF communities in karst shrub ecosystem.We explore the effects of karst heterogeneity habitat microhabitat on shrub community and soil AMF community,and the relationship between aboveground shrub community and underground AMF community in karst shrub ecosystem.These results provided helpful information for the vegetation restoration combined with AMF.The main results are summarized as follows:Shrub and AMF species were richness in shrub ecosystem.141 species of woody plants were observed,which were belonging to 36 families and 91 genera.The species of Vitex negundo,Tirpitzia ovoidea and Zanthoxylum echinocarpum were the dominant species.The soil AMF was divided into 7 families and 10 genera,and Glomus is the absolute dominant species in this regions.The diversity of AMF community was affected by the interaction of seasonal variation and habitats.The diversity and abundance of soil AMF community in winter were significantly higher than that in summer.The traditional habitat division(soil surface?soil?stone ditch)was more suitable for the research of aboveground vegetation and underground AMF community compared with bare rock rate division in karst area.The diversity of shrub community and soil AMF community was significantly affected by stone surface and stone ditch.the distribution of soil organic carbon,available phosphorus(AP),available nitrogen(AN),total nitrogen(TN),total potassium(TK),calcium(Ca2+)and magnesium(Mg2+)were shown as stone ditch>soil surface?soil(except TK,P<0.05).Redundant analysis showed that soil total phosphorus play an important role on AMF community diversity.A good species-area relationship between sample area and shrub community,AMF community was observed,but the area that they reached plateau phase of species diversity was different(plant community richness was still rising when the sanple area on 4096 m2,and AMF community richness has reached plateau phase when the sample area on 256 m2).Meanwhile,the results showed that a correlation relationship between the community composition of shrub and the AMF in the study area was observed,but there was a faint correlation relationship between the shrub community and the AMF community.The structural equation model showed that the diversity of AMF community was mainly affected by available phosphorus and pH.In summary,in karst area,there was rich AMF resources in shrub ecosystem,and the distribution of aboveground shrub communities and underground AMF communities were affected by microhabitat types.The diversity of shrub community and AMF community were significantly different in different niches.The diversity of AMF community was related to the shrub community,plant communities 2,3,8,1 8 affect the distribution of AMF community.In addition to the host plants,the diversity of the AMF community was largely affected by soil which was restriction by environmental heterogeneity.In conclusion,the effects of niche heterogeneity on vegetation communities and underground AMF communities should be take into account,when the AMF was applied into vegetation restoration,in karst area.