Study On Soil Fungi Under Different Vegetation Restoration Patterns And The Effect Of Nanomaterials On Soil Physical And Chemical Properties And Enzyme Activities

Coal mining has caused serious ecological damage and environmental pollution,and soil restoration in mining areas has now become a research focus in the field of ecological environment.Because of its large specific surface area and microporosity,nanomaterials have super adsorption,catalysis,and chelating abilities,and are often used to remove heavy metals and organic pollutants in contaminated soil.In recent years,many scholars have proposed that nano-iron particles are expected to be a new technology for remediation of contaminated soil.Although nano-iron has been proven to have potential benefits,the potential risks of environmental exposure to nano-iron still need to be determined.Based on the BEF sample plot of the Antaibao open-pit coal mine dump,this study analyzed the effects of different vegetation combination restoration modes on the soil microbial community structure and diversity in the mining area reclaimed land,in order to provide a basis for the screening of the reclaimed vegetation in the mining area;at the same time;Select Fe nanoparticles(Fe NPs)with different concentration gradients to add to several better vegetation combination restoration models,explore the physical and chemical properties of different concentrations of Fe NPs on the vegetation restoration soil,the number of fungi,and the activities of four soil enzymes(over The influence of catalase,invertase,urease,alkaline phosphatase)provides a reference for the joint restoration of contaminated site soil with nanomaterials and plants.The results of the study are as follows:(1)At the phylum taxonomic level,the dominant fungal phyla of the vegetation model selected in this study are Ascomycota and Basidiomycota,and the fungi content of the two groups accounted for more than 80%,of which Ascomycota has the most obvious advantage.At the genus level,the relatively abundant ones are Tuber,Mortierella,Cordyceps,Gibberella,Marasmiellus,Suillus and others are the dominant bacteria genera,of which Truffle and Suillus are all concentrated in the YS model(51.52% and 10.85%respectively)and the plots of multiple vegetation combination patterns dominated by YS,Microderma is all concentrated in the NT model(accounting for 11.57%)and a variety of vegetation combination model plots dominated by NT.(2)The results of CCA analysis of soil dominant fungi in different vegetation models and 5 soil physical and chemical factors show that AP and OM two environmental factors have significant effects on soil fungal communities,and OM(P<0.001)affects all model soil fungal communities The main factor of YS＿CH,followed by AP(P<0.05),and OM has the greatest impact on YS＿CH.However,AK only had a significant effect on the composition of soil fungal community in the CH＿YS＿SJ＿NT vegetation combination model(P<0.05).In the results of Spearman correlation analysis,soil OM was significantly correlated with 7 dominant bacterial genera,and soil TN was significantly correlated with 4 dominant bacterial genera.(3)Different physical and chemical factors have different adaptability to Fe NPs.After a week of incubation at room temperature,Fe NPs can lower the p H of the soil,thereby alleviating the p H of the reclaimed soil.The neutral acid-base conditions can provide a better living environment for soil microorganisms.Fe NPs at a low concentration(1 μg/g)have a promoting effect on soil OM,thereby improving soil C cycle related processes,and creating favorable conditions for microorganisms to increase the growth and reproduction of fungi.Under the treatment of high concentration Fe NPs(100 μg/g),AP increased,and the abundance value of fungus number also increased.(4)Fe NPs have an inhibitory effect on soil catalase in YS mode and YS＿CH＿SJ mode,and have a promotion effect on YS＿CH mode and YS＿CH＿SJ＿NT mode,and the promotion effect of low concentration treatment group is stronger.Fe NPs can promote the rental of soil invertase in the four vegetation restoration combined modes,and the high concentration of Fe NPs and the YS＿CH mode can greatly increase the soil invertase activity after a long period of time,thereby promoting the growth of soil microorganisms and being related to the C cycle Series of reactions.After adding Fe NPs in the four vegetation combination restoration modes,the soil urease activity was promoted in a short time,and its N supply capacity to plants was improved.The YS model is more tolerant to Fe NPs.Although it is inhibited at the beginning of culture,the soil alkaline phosphatase activity increases sharply after long-term culture with high concentration of Fe NPs(100 μg/g).In a relatively short period of time,Fe NPs can promote the soil alkaline phosphatase activity in the YS＿CH mode,YS＿CH＿SJ mode and YS＿CH＿SJ＿NT mode to varying degrees,thereby promoting a series of related reactions such as the P cycle in the soil ecosystem.