Relationships Among Leaf Functional Traits And Its Provenance Variation For Larix Gmelinii And Pinus Koraiensis

The variations of leaf functional traits and their relationships can represent the response of plants to environmental changes and ecological adaptation strategies.Larch Dahurian（Larix gmelinii）and Korean pines（Pinus koraiensis）are the main timber species in northeast China,because they have the wide range of distributions and the complex and changeable growing environment,so they are ideal tree species to research the variations of leaf functional traits.In this study,Larix gmelinii from 17 provenances and Pinus koraiensis from 26 provenances were transplanted into a common garden,we measured the leaf stoichiometric characteristics(including mass-based leaf carbon concentration(C_mass),mass-based leaf nitrogen concentration(N_mass),mass-based leaf phosphorus concentration(P_mass),the ratio of C_mass to N_mass（C/N）,the ratio of C_mass to P_mass（C/P）,the ratio of N_mass to P_mass（N/P）),photosynthetic traits(including maximum net photosynthetic rate(A_max),maximum electron transport rate(J_max),maximum carboxylation rate(V_max))and morphological trait（Specific leaf area（SLA））,we compared the differences of relationships in leaf functional traits among different species and provenances,and analyzed the differences in leaf functional traits among provenances and the dynamic of seasonal and leaf ages.The main results are as follows:（1）The correlation relationships and differences among provenances between leaf stoichiometric characteristics and photosynthetic traits of Larix gmelinii.C_mass,N_mass and P_masswere significantly positively correlated with A_max,J_max and V_max,while C/N,C/P and N/P were significantly negatively correlated with photosynthetic traits.The trees with higher AI had higher sensitivity of A_max with the N_mass increased.Leaf stoichiometric characteristics explained75.0%variation of photosynthetic traits,and the main influencing factors were N_mass and P_mass.The variation coefficients ranged from 2.32%to 47.38%and significant differences among provenances in C_mass,N_mass,P_mass,C/N,C/P,N/P,A_max,J_max,V_max.The climatic factors of seed-source sites accounted for 52.2%variation in leaf stoichiometric characteristics and 64.9%variation in photosynthetic traits,the main influencing factor was AI.C_mass,N_mass,P_mass,A_max,J_max and V_max were positively correlated with AI,while C/N,C/P,N/P were negatively correlated with AI.C_mass,N_mass,P_mass,A_max,J_max and V_max firstly increased and then decreased,while C/N,C/P and N/P firstly decreased and then increased.（2）The correlation relationships and differences among provenances between stoichiometric characteristics and morphological trait of Pinus koraiensis.SLA was significantly positively correlated with P_mass,but negatively correlated with C_mass,N_mass,C/P and N/P.The trees with higher MAP had higher sensitivity of SLA with the C_mass,P_mass,N/P increased.Leaf stoichiometric characteristics accounted for 62.0%variation of morphological trait,and the main influencing factor was N_mass.The variation coefficients ranged from 2.69%to 19.49%and significant differences among provenances in C_mass,N_mass,P_mass,C/N,C/P,N/P and SLA.The climatic factors of seed-source sites accounted for 21.0%variation of leaf stoichiometric characteristics and morphological trait;the main influencing factor was mean annual precipitation（MAP）.N_mass and P_mass were negatively correlated with MAP,C/N and C/P were positively correlated with MAP,SLA was negatively correlated with mean annual temperature（MAT）.With the increase of leaf ages,C_mass significantly increased,N_mass first increased and then decreased,P_mass and SLA significantly decreased,C/N first decreased and then increased,and C/P and N/P first increased and then stabilized.（3）There were significant differences in stoichiometric characteristics of Larix gmelinii and Pinus koraiensis.C_mass and N_mass,C/P and N/P were significantly of Larix gmelinii higher than those of Pinus koraiensis,but P_mass and C/N were lower.There was a significant positive correlation between C_mass,N_mass,P_mass and C/N,C/P,and N/P in Larix gmelinii.There was significant positive correlation between C_mass and N_mass,but negative correlation between P_mass,N_masswith P_mass had no correlation of Pinus koraiensis.C/P was positively correlated with C/N and N/P,C/N was negatively correlated with N/P.These results indicated that there were different response strategies were displayed between Larix gmelinii and Pinus koraiensis in different environmental levels.The relationships between leaf functional traits were a little affected by the environment of seed-source sites,while leaf functional traits were dominantly affected by the environment of seed-source sites,which was the result of long-term adaptation to the environment of seed-source sites and acclimation of the environment of common garden.In addition,the relationships between leaf functional traits had differences in different species,which was conducive to the survival and reproduction of trees in diverse environments.