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本文探讨了5年生杉木树冠的结构特点及其与植株生物量的关系。不问冠型如何,同一林分幼杉各器官干重的比重都比较稳定;树冠针叶干得密度为0.18—0.44千克/米~3,针叶面积(仅计一面)密度为0.97—2.40米~2/米~3,比Kira等(1969)报道的阔叶树的叶面积密度大4—5倍;针叶主要着生在二级和一级侧枝上,集中分布在树冠中下部。闽北地区Ⅱ一Ⅲ地位级杉木造林后4年内干物质生产速率平均为345克/米~2/年,对辐射能的利用率为0.17％。浓密型杉木的生长要显著快于稀疏型杉木。 根据幼杉冠层结构的特点,提出:(1)应加强幼林抚育,改善中下部林冠的光照条件,以发挥比重最大的中下部冠层针叶的光合潜力;(2)为使幼杉树冠发育良好,闽北地区Ⅱ—Ⅲ地位级杉木的栽植密度应在2×2米至2×3米之间;(3)为提高杉木幼林期林地的光能利用率,可在幼林内间作农作物;(4)抚育采伐时应尽量保留浓密型杉木而去除稀疏型杉木;(5)可以考虑把浓密型杉木单独造林;(6)可以指望把浓密型杉木作为优良的育种原始材料。
This paper explores the structural characteristics of 5-year-old Chinese fir canopy and its relationship with plant biomass. Regardless of crown type, the proportion of dry weight of organs in the same stands was relatively stable; the density of needles in crown was 0.18-0.44 kg / m ~ 3, and the density of needles (only one side) was 0.97-2.40 M ~ 2 / m ~ 3, which is 4-5 times larger than the leaf area density of broad-leaved trees reported by Kira et al. (1969). Needles mainly live on the secondary and primary branches, which are concentrated in the middle and lower parts of the canopy. The average dry matter production rate of 345-gm-2 / yr after 4-year afforestation of Ⅱ-Ⅲ status-grade Chinese fir in northern Fujian was 0.17% for radiant energy. Thicker fir growth is significantly faster than the sparse fir. According to the characteristics of the canopy structure, the author proposed: (1) Young trees should be nurtured to improve the light conditions of the middle and lower canopy in order to exert the photosynthetic potential of middle and lower canopy needles with the largest specific gravity; (2) Well-developed, planting density of Ⅱ-Ⅲ status fir in northern Fujian should be between 2 × 2 and 2 × 3 m; (3) To improve the light energy utilization rate of forestland in young period, ; (4) When firing and cutting should be kept as dense as possible to remove sparse fir fir; (5) can be considered separately afforestation fir plantation; (6) can be expected to use dense fir as a good breeding material.