The Xylem Hydraulic Architecture Characteristics Of Key Phenology For The Major Tree Species Of Northeast China

Under the background of global climate change,the increase of temperature,the change of rainfall pattern and the length of sunshine,etc,lead to the change of plant phenology and water use.Therefore,it is of great significance to understand the water transport strategies of different tree species and different phenological stages in order to predict the adaptation of plants to climate change and to provide reference for ecological construction.In this study,nine main tree species {Ulmus japonica,Quercus mongolica,Betula platyphylla,Acer mono,Tilia amurensis,Larix gmelinil,Pinus koraiensis,Picea koraiensis)with different wood properties(diffuse-porous,ring-porous and non-porous)were selected.The hydraulic conductivity,stem specific conductivity,leaf specific conductivity,Huber value,sapwood area of branch segment,total leaf area at the end of branches,and specific leaf mass of 9 species in phenological stages(Sprouting,Bud swelling,beginning of leaf expansion,peaking of leaf expansion,leaf discoloration,leaf falling,dormancy)were measured.The variation and difference of hydraulic structure parameters of plants in different phenological stages and the relationship between hydraulic structural parameters and leaf characters and environmental temperature were analyzed.The main findings are as follows:(1)The hydraulic architecture parameters of different tree species have obvious phenological variation.The maximum water conductivity of diffuse-porous,ring-porous and non-porous tree species is 4-8,3-6 and 2-4 times of the minimum value,and the maximum specific conductivity of stem is 4-5,5-7 and 2-4 times of the minimum value.The maximum value of leaf specific conductivity is about 1-2 times the minimum value.The maximum value of the Huber value is about 1-3 times the minimum value.(2)During the same phenological period,there were significant differences in hydraulic structural parameters among different tree species.In addition to the sprouting stage,the water conductivity of the ring-porous tree species is the largest.In addition to the bud swelling,the stem specific conductivity of diffuse-porous tree species is the largest.The leaf specific conductivity of diffuse-porous tree species was the largest,and the Huber value of the non-porous tree species was the largest.(3)The sapwood area of branch segment was positively correlated with conductivity and Huber's value(P<0.01),negatively correlated with stem specific conductivity(P<0.01),and significantly correlated with leaf specific conductivity(P=0.03).There was a significant positive correlation between the total leaf area at the end of branches and conductivity(P<0.01),but not with stem specific conductivity,leaf specific conductivity and Huber value.The ratio of specific leaf mass was negatively correlated with conductivity,stem specific conductivity and leaf specific conductivity(P<0.05),and positively correlated with Huber value(P<0.01).The soil temperature was very significant positively correlated with the stem specific conductivity of diffuse-porous tree species and ring-porous tree species(P<0.01).There was a significant positive correlation between soil temperature and leaf specific conductivity(P<0.05).There was a significant positive correlation between air temperature and stem specific conductivity of diffuse-porous tree species(P<0.05).