A Study On The Characteristics And Influencing Factors Of Foliar Nutrient Resorption Of Pinus Massoniana In Soil Erosion Area Of Changting

In this paper,we regard the Pinus massoniana which is pioneer tree in ecological restoration of Changting soil erosion area as main object.Using random sampling and typical sampling method,and build natural nutrient gradients.To explore the effects of soil nutrient status,leaf nutrient status and individual size on nutrient reabsorption of Pinus massoniana.With a view to reveal the nutrient cycling law of Pinus massoniana coniferous and the efficient nutrient use strategy.Research indicates that soil nutrient content,potency and stoichiometric ratio had no significant effect on N,P,K reabsorption efficiency and reabsorption proficiency of Pinus massoniana.Pinus massoniana has long lived in a nutrient-poor and proportionally imbalanced environment that has already developed a specific nutrient use strategy to meet the nutritional needs of its own growth by selecting a regimen restriction element.The nutrient status of leaf had some effects on nutrient reabsorption efficiency and reabsorption proficiency of Pinus massoniana,and the N and P efficiency were positively correlated with the corresponding element contents in mature leaves,and the reabsorption efficiency of N,P and K was negatively correlated with the corresponding nutrient content in senescent leaves.This indicates that the lower the nutrient content of Pinus massoniana leaves,the higher the degree of nutrient reabsorption and the higher nutrient reabsorption efficiency.The effect of the stoichiometric ratio of Pinus massoniana on the reabsorption capacity of different elements was not consistent.The N/P of senescence leaves can better’ reflect the N,P reabsorption capacity of Pinus massoniana.The size of the individual had some effect on the N reabsorption efficiency of Pinus massoniana,but had no significant effect on P and K reabsorption efficiency.There was no significant difference in the content of N,P and K in different size of Pinus massoniana,and there was no significant difference in the reabsorption proficiency of N,P and K between different sizes of Pinus massoniana.Long-term survival of Pinus massoniana in the low nutrient environment by reducing the nutrient content of senescence leaves to reduce nutrient loss is the result of long-term adaptation of Pinus massoniana to barren nutrient environment,showing an inherent property of species.This study provides some theoretical guidance for vegetation reconstruction and nutrient management in Changting soil erosion area and provides basic data for the relevant research on nutrient reabsorption at global scale.