Leaf Carbon,Nitrogen And Phosphorus Stoichiometry Across Plant Species In The Arid To Semi-humid Regions,North China

Leaf carbon,nitrogen and phosphorus stoichiometry across plant species is the result of long-term adaptation to the enviorment of plants,which is one of the hot topics in the ecological researchs.This study analyzed the distribution characteristics of leaf C,N and P content and their stoichimetric ratio,and explained the relations between leaf C,N and P stoichiometry with enviormental factors and plant life-forms,and also explored the mechanism of its formation based on 247 plants distributed from arid to semi-humid regions in 40 oN of China.The main results of this study are shown as follows:1.With the increase of longitude,Leaf Carbon content increase linearly,Nitrogen and Phosphorus content linear decrease and leaf mass per area(LMA)increase linearly,which form the pattern of C:N and C:P linear increase with the increase of longitude,but N:P was not significant.This result illustrate that although there is exist differences of plant construction cost(LMA,C),but N:P have the coordination in different natural ecological systems.2.In tree plants,leaf C content is the highest,but N and P is the lowest,however,leaf C content of the herbs and shrubs is lower and N,P content is relative high,which form the pattern of leaf C:N and C:P of trees significantly higher than that of herbs and shrubs.The three kinds of plant life-forms leaf N:P was nonsignificant difference that reflect leaf N and Pcontent was relatively consistent among different plant life-forms.3.With the increase of longitude,the mean annual precipitation(MAP)incease linearly and the mean annual temperature(MAT)have little change,which form the pattern of leaf C content linear increase with the increasing of MAP and leaf N and P content decrease linearly,but there is no linear relation between leaf C,N and P content with MAT,which explained leaf C,N and P content stoichiometry in arid to semi-humid regions is more affected by the MAP.The relation of different plant life-forms leaf C,N and P content and MAP,MAT also similar.4.Through the soil nutrient content and MAP,MAT regression analysis found that the relation between soil total N and total P content with is significant,and is not associated with MAT.There is significant relationship of leaf C,N and P stoichiometry with soil total N and total P content which explained the relationship between leaf C,N and P stoichiometry with precipitation was eatablishing by precipitation affects soil nutrient content,and soil nutrient content affect leaf C,N and P stoichiometry.