Stoichiometric Characteristics And Influencing Factors Of Plant Leaves C,N And P

The stoichiometric characteristics of plant leaves C,N and P can reflect plant survival mode and nutrient utilization strategy.The study of plant stoichiometry characteristics in different regions of China is helpful to understand the nutrient utilization strategies of plants in different regions of China,and is of great significance for predicting plant growth strategies under future global changes.In this study,the content and ratio of leaves C,N and P in 22 cities in 5 climate zones in China were studied,and the spatial distribution characteristics of plant leaves C,N and P stoichiometric characteristics in different regions of China and the relationship between different influencing factors were revealed,and their ecological significance was discussed.The results of the study are as follows:(1)The range of leaf C element content was 292.32mg/g～617.59mg/g,the average value was 452.01mg/g,the content distribution range of leaf N element was 4.80mg/g～78.37mg/g,the average value was 28.41mg/g,the range of leaf P element was 0.33mg/g～8.48mg/g,and the average value was 2.26mg/g.The C/N in the leaves is between 2.79～86.55,and the average value is 18.31.The range of blade C/P is 40.53～1241.19,and the average value is 255.72.The range of blade N/P is 1.83～41.55,and the average value is 14.66.(2)There was no obvious trend of change in the spatial distribution of leaves C and P.The content of leaf N was higher in the western region than in the eastern region,and the content of leaf N in the northern region was higher than that in the south.The utilization efficiency of N elements by plants was higher in the southeast region and lower in the western region.The utilization efficiency of P element by plants is roughly bounded by Heihe-Tengchong,which is higher in the southeast and lower in the northwest.In this study,52.98% of vegetation growth was limited by N element,34.46% of vegetation growth was limited by P element,and only 12.56% of vegetation was limited by both or neither element was lacking.(3)Among different life forms,the leaf C content of arbor plants was the highest,and the leaf C content of herbaceous plants was the lowest.The leaves of herbaceous plants had the highest content of N and P,shrub plants had the lowest content of N leaves,and trees had the lowest content of P in leaves.The utilization efficiency of N and P elements in trees and shrubs is generally higher than that of vines and herbaceous plants.(4)Among the different climatic zones,plants in tropical monsoon climate zone and subtropical monsoon zone had higher utilization efficiency of N and P elements,and plants in highland mountain climate zone had the lowest utilization efficiency of N and P elements.Plant growth and physiological activities in temperate continental climate zone and tropical monsoon climate zone are limited by N element,plants in temperate monsoon climate zone and plateau mountain climate zone are limited by N and P elements at the same time or these two elements are not lacking in the growth and development of vegetation,and vegetation growth physiological activities in subtropical monsoon climate zone are limited by P element.(5)The stoichiometric characteristics of leaves responded differently to different influencing factors,and the contents of C,N and P of plant leaves had a high degree of response to climatic factors,leaf traits,latitude,altitude and S,K,Mg and Cu elements.The utilization efficiency of N and P elements by plants is not only affected by external environmental factors,but also related to the plants themselves.Mineral elements and leaf traits have little influence on plant nutrient restriction pattern,and the external environment has a greater influence on plant nutrient restriction pattern.