不同年龄白桦比叶面积的生长阶段变异及冠层差异 / Variations of Specific Leaf Area in Different Growth Periods and Canopy Positions of Betula platyphylla at Different Ages
In this study, we investigatedvariations of specific leaf area (SLA) indifferent growth periods and canopy positions of Betula platyphylla at different ages, and analyzed the effects of different resources and environment conditions on SLA and its relationship with other leaf traits,which wouldhelp us to learn more about SLA variations and its influencing factors and provides the basis for better understanding of the impact of resources and environment on the traits.[Methods] B. platyphylla, an early successional tree species of broadleaved-Korean pine (Pinus koraiensis) forest, was selected as the study object. During the growth periods of leaf growth (June), leaf stabilization (July) and leaf senescence (September), the SLA, leaf thickness (LT) and leaf dry matter content (LDMC) of adult trees and saplings were measured, and the SLA, LT and LDMC in different canopy positions of adult treeswere also measured. The variation of the three leaf traits and their relationships in different plant ages, growth periods, and canopy positions were analyzed.Further, we tested whether plant age, growth period and canopy position significantly affected these relationships by using Standardized Major Axis (SMA) method.[Result] There were significant variations in SLA, LT and LDMC of adult trees and saplings in different growth periods and canopy positions. The influence degree of LT, LDMC and LT×LDMC on SLA significantly varied with plant ages. There were significant negative correlations between SLA and LT, LDMC in different plant age, growth stage and canopy height and the slopes between SLA-LT and SLA-LDMC differed significantly with plant ages,growth periods and canopy positions.[Conclusion] SLA of B.platyphylla at different plant ages decreased significantly with growth periods, and increased significantly with the decrease of canopy positions,and the relationship between SLA and LT, LDMC wassignificantly influenced by plant age, growthperiod and canopy position.
Abstract in Chinese and English, paper in Chinese only.