| The C,N,P contents and stoichiometry of leaf,root system,soil and microbial biomass were analyzed in this paper,and the stoichiometric characteristics and relationships on the basis of various "plant-soil-microorganism" remediation system.The main findings are as follows: The leaf C contents were as follows: Robinia pseudoacacia forest & gt;Seabuckthorn forest & gt;Weeds;N and P contents were the same.The leaf and root C/N and C/P of Robinia pseudoacacia forest were higher than others,which indicated that the Robinia pseudoacacia forest had higher adaptation to the study area.Leaf N/P at 8.2?11.7 & lt;14.4,indicate that plant growth processes in this area are limited by N.There was no significant difference in the C,N contents of 0-20 cm soil layer than that of 20-40 cm,P.There was no significant difference between soil C/N,C/P and N/P.Compared with the Weeds,Robinia pseudoacacia and Seabuckthorn forest significantly increased the microbial biomass C,N,P contents.The microbial biomass C/N was low and no difference in the three remediation models.The microbial biomass C/P and N/P of Robinia pseudoacacia forest were significantly lower than those of Seabuckthorn forest and Weeds,which may be due to the higher effectiveness of soil P of Robinia pseudoacacia forest than that of Seabuckthorn and Weeds.There was a significant correlation between root N and P,leaf N and soil C,N,root N and soil N,P in Robinia pseudoacacia forest and Seabuckthorn forest.The relationship between leaf and root C,N is relatively closer than P,and all have very significant correlation,further indicating that plants under the three repair models are limited by N.A significant correlation was also found between leaves,roots,soil and microbial biomass C/N,N/P,C/P under plantation remediation.While the C/N,C/P,N/P and microbial biomass of leaves and roots under natural recovery C/N,C/P,N/P not significant.The thesis has 37 pictures,7 tables and 101 references. |
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