Study On Ecological Stoichiometric Characteristics Of Leaves-soil System Of Populus Euphratica Typical Plot

Leaves-soil carbon(C),nitrogen(N),phosphorus(P)and their stoichiometric characteristics(C:N:P)play an important role in nutrient limitations,community dynamics,nutrient use efficiency and biogeochemical cycles.This study took Populus euphratica as the research object,systematically sampled the distribution areas of typical Populus euphratica forests in Yafuquan,Shaya,Luntai regions,and explored the responses of C,N,P content and their stoichiometric characteristics of Populus euphratica leaves and different soil layers to regional climate conditions.By using redundant analysis analyzed the relationship between leaves-soil and environmental factors to clarify the mechanism of leaves-soil interaction.Relevant research can enrich the research content of ecological stoichiometry in arid areas,and also has practical significance to provide theoretical support for formulating the protection strategy of Populus euphratica forest ecosystem.The main conclusions are as follows:(1)The mean values of leaf C,N,P contents in Populus euphratica are 453.726 g/kg,11.448 g/kg,0.959 g/kg,respectively.The mean values of leaf C:N,C:P,N:P ratio are39.776,504.669,12.263,respectively.The correlation between leaf C and N,P is not significant,and there is an extremely significant correlation between leaf N and P;leaf C:N,C:P,and N:P ratios are all affected by the contents of C,N,and P.(2)Mean annual temperature(MAT)is significantly or extremely significantly correlated with leaf C content,P content,and C:P ratio;Mean annual precipitation(MAP)is negatively correlated with leaf C content,significantly,and negatively correlated with C:N ratio,significantly;latitude is negatively correlated with leaf N: P ratio,significantly;diameter at breast height has a significant correlation with leaf N content,C:N ratio,and N:P ratio;tree height is significantly positively correlated with leaf C content.(3)The mean values of C,N,P contents in the 0-30 cm layer of soil are 3.474 g/kg,0.514 g/kg,0.6838 g/kg,respectively.The mean values of C:N,C:P,N:P ratio in the 0-30 cm layer of soil are 8.8459,4.9498,0.8134,respectively.Correlation between soil C and N and P is positive,significantly,while the correlation between N and P is not significant.The mean values of C,N,P contents in the 30-80 cm layer of soil are 1.892 g/kg,0.2572g/kg,0.445 g/kg,respectively.The mean values of C:N,C:P,N:P ratio in the 30-80 cm layer of soil are 11.021,4.711,0.6425,respectively.There is an extremely significant correlation between soil C and N,positively.The correlation between soil C and P is not significant,and the correlation between soil N and P is not significant.(4)MAT is significantly positively correlated with 0-30 cm soil C and P content,and30-80 cm soil P content is also significantly positively correlated with it;MAP is significantly negatively correlated with 0-30 cm soil C content,and it is extremely significantly correlated with 0-30 cm soil P content,negatively,and it has extremely significantly negative correlation with P content in the 30-80 cm layer of soil.(5)Leaf C content has significant or extremely significant correlation with 0-30 cm soil C,N,P content,30-80 cm soil P content and C:P ratio;There is a significant or extremely significant correlation between the leaf N content and the soil P content in both0-30 cm layer and 30-80 cm layer soil;the leaf P content has a significantly negative correlation with the 0-30 cm soil P;the leaf C:N ratio and the 0-30 cm soil P content,30-80 cm layer soil P content has significant or extremely significant correlation;leaf C:P ratio has significant or extremely significant correlation with 0-30 cm soil C and N content;leaf N:P ratio has a significant correlation with 0-30 cm soil N content,N:P ratio.(6)Redundant analysis results show that among the soil environmental factors in the0-30 cm layer soil,MAP,CEC,and MAT have the highest degree of interpretation for leaf stoichiometric characteristics;MAP,BD,and SWC have the highest degree of interpretation for soil stoichiometric characteristics.Among the soil environmental factors in the 30-80 cm layer soil,BD,p H,and SWC have the highest degree of interpretation for stoichiometric characteristics in leaves;EC,CEC,and BD have the highest degree of interpretation for stoichiometric characteristics of soil.