Soil Physicochemical Properties And Fungal Diversity Of Three Plant Regions In Anda Saline-Alkali Land

Anda is located in the southwest of Heilongjiang Province.As the "land of Leymus chinensis" in China,it is also one of the three high quality grasslands in the world.In recent years,due to some human and natural factors,the soil of Anda grassland has gradually been salinized and alkalized.The material transformation and energy cycle in the soil requires the participation of soil microbes,and the study of soil microbial parameters accounts for a large proportion in the evaluation of ecosystem conditions.Salinization of soil in an area results in changes in above-ground vegetation communities and underground soil microbial communities.So far,the research on the saline-alkali grassland in Anda is mainly in the agriculture and animal husbandry economy and macro-improvement measures,while the research on the microbial community of the underground soil is still rare.In this study,Alkali spots were selected as the control,and the three plants:Puccinellia chainampoensis Ohwi,Salix linearis stipularis K.S.Hao and Populus davidiana Dode x R bolleana Lauche were selected to collect rhizosphere soil samples in their respective distribution areas,and soil physicochemical properties were determined.The rDNA-ITS sequencing technology was used to analyze soil fungal community structure in three plant growth areas,and relationship between soil fungal communities and soil environmental factors in different habitats were analyzed by Canonical correspondence analysis.The main results are as follows:(1)Among the four habitats,the alkali spot is highly salinized and alkalized area,the soil salinity and alkalinity in the Puccinellia chainampoensis area are second only to alkali spots.The total salt content of the Salix linearispularis area is higher than that of the Populus area,and the pH value is lower than that of the Populus area.The soil fertility of Salix linearispularis area is the best,followed by the Puccinellia area.Pearson correlation shows strong or weak correlation between different soil factors in the same habitat.(2)Based on the relative abundance of the species in at least one sample of more than 0.1%,the high-throughput sequencing result shows that there has more number of unique OTUs in Puccinellia area.The species annotations were classified into 6 classes,16 classes,33 orders,59 families,76 genera,and 54 species.The diversity of soil fungi in Puccinellia area was the highest,and the fungi community structure in the three plots was more similar,and there were the most fungi with significant difference in abundance.The fungi community structure of three plots was similar,and the fungi evenness was higher while the fungi richness was low in Salix area.The fungi richness is higher and evenness is low in Populus area,and the fungi with significant difference in species richness are the least.(3)The structural differences of soil fungal communities in the three plant distribution areas of Anda saline-alkali soil are related to soil factors.The Puccinellia area ware most affected by the total salt content.The soil fungal richness and species number were strongly correlated with soil total nitrogen,phosphorus and potassium contents.The fungal evenness was significantly correlated with organic matter contett and urease activity,and has extremely strong correlation with pH value and total salt content.The Salix linearispularis area was most affected by the total nitrogen content.The fungal richness was strongly correlated with the organic matter content,total nitrogen content and urease activity.The fungal evenness was significantly correlated with the total potassium content.The Populus area is most affected by soil total phosphorus,and the soil fungal diversity is strongly correlated with total phosphorus content.The number of species is also strongly correlated with total potassium.The contribution of total salt content to the classification level of fungal species is the largest in the classification of fungal species except "species".At the "species" level of fungi,the contribution of soil total phosphorus is the largest.In summary,from the soil physicochemical properties and fungal community structure of the habitats in Anda saline-alkali land,the salt tolerance of the herbaceous plants is stronger than that of woody plants,while the salt-tolerant adaptability of Salix linearispularis is stronger than that of Populus.Populus has no growth advantage in Anda saline-alkali land,and the soil physicochemical properties of Salix linearispularis area is better than other areas.Salix linearispularis should be given more attention in the follow-up study on vegetation replacement in saline-alkali land reconstruction.