关键词: 植物功能型, 叶经济谱, 功能性状

Abstract: In order to explore the effects of shrubs on the growth of 9-year-old saplings of Pinus tabuliformis on the Loess Plateau, the saplings were planted in 3 types of habitats: the edge of shrubs, the central of shrubs and shrubcutting release area. The characteristics of crown shapes and the growth conditions of currentyear trunk, branch and leaf of samplings were compared. The results showed that the tree height was not significantly different among the 3 habitats. The crown width, living crown ratio, the duration years of green leaves in the branch, basal diameter of the saplings all changed with the same pattern across the three habitats, being ranked as the edge of shrubs>shrubcutting release area>the central of shrubs; however, the height under branch showed an opposite pattern among habitats. The crown shapes did not differ between the central of shrubs and shrubcutting release area. The growth of the currentyear trunk, branch and leaf of P. tabuliformis was affected by shrubs only when the saplings were lower than the shrubs. The negative effects of shrubs on the growth of such saplings were alleviated by forest tending measures in the shrubcutting release area. The saplings changed their crown shape by selfpruning. They would take some bionomic strategies to adapt to the environment when they were shaded by the shrubs, such as allocating more biomass to the growth of length than to the growth of diameter in currentyear trunk and branch, increasing leaf biomass proportion at the branch level, and increasing specific leaf area.

Key words: leaf economics spectrum, functional trait., plant functional type