疏伐促进杉木种子园开花结实的研究

Effects of Plant Thinning on Clone’s Flowering and Seeding in Chinese Fir Seed Orchard

据对３个１２年生的杉木种子园进行强度为２０％～３０％的疏伐，经连续３ａ的观测研究表明，与未疏伐的对照相比较，疏伐后无性系的雌花量平均增长到４．１７倍，雄花量平均增长到２．７１倍，疏伐小区球果平均每公顷产量是未疏伐（对照）小区的１．３９～１．６３倍，单株球果平均产量是未疏伐区单株产量的１．４１～２．２１倍。同时疏伐区接株的树高、胸径和侧枝当年生长量比对照也有明显的增长。

The plant thinning with the intensity at 20%～30%was conducted in three12-year-old Chinese fir seed orchards and the observations were made in the later threeyears. It showed that clones′ averaged amount of female cone flowers produced by the forestswhere it have been thinned is 4.17 times that of the check,and the male cone flowers is 2.71times of the check.The per hm2 yield of cone in thinned plot is 1.39～1.63 times that of theuntreated,and the single tree yield of cone in thinned plot is 1.41～2.21 times that of the un-treated. Meanwhile,the yearly growth of the plant height,DBH and lateral branch also in-creased obviously.