Correlations between Needle Length and Leaf Hydraulics,Structure in Five Pinus Species
[Objective]The purpose of this study was to explore the relationship between pine needle length and leaf hydraulic function,structure in Pinus species.[Method]In this study,the hydraulic con-ductance,resistance distribution and anatomical structure of needles in five Pinus species(Pinus echinata Mill.,P.elliottii Engelm.,P.palustris Mill.,P.taeda L.,P.virginiana Mill.)were meas-ured,and the interspecific variation of these indexes and their relationship with needle length were ana-lyzed.[Result]The needle length have a range of 7.5～34.6 cm in five Pinus species,with the increase of needle length,the leaf hydraulic conductance(Kleaf),xylem conductance(Kxylem),outside-xylem conductance(Koutside-xylem)and pit conductance(Kpits)increased,but the tracheid lumen conductance(Klumen)decreased.The increase in Kleaf was associated with the co-increase in Kxylem and Koutside-xylem,and the increase in Kxylem was mainly caused by the increase in Kpits.In terms of hydraulic resistance,the dis-tribution proportion of hydraulic resistance in the needle xylem was significantly higher than that outside the xylem,and it was not related to the change of pine needle length.The distribution proportion of hy-draulic resistance in the tracheid lumen increased significantly with the increase of needle length,which might be due to the increase of the axial water transport distance.[Conclusion]The needle length of Pinus species is closely related to the leaf hydraulic function and anatomical structure.The results of this study reveal the relationships between leaf size and leaf hydraulic function and structure,which is of great sig-nificance for understanding the relationships among leaf functional traits.
万方数据
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