中龄林修枝对杉木林生长和材种结构的影响研究

In order to cultivate the knot-free log of Chinese fir and explore the influence of pruning on the growth and timber structure of Chinese fir,a pruning and non-pruning experiment of Chinese fir plantation was designed in 2003 with 17-year-old Chinese fir middle-aged plantation as the research object.In 2023,the effects of pruning on the growth and timber structure of Chinese fir plantation were studied after 20 years of pruning in middle-aged plantation.The results showed that the annual growth of DBH of Chinese fir was significantly promoted within 2 years before pruning in middle-aged plantation,and there was no significant effect on the annual growth of tree height and volume.Then,the effect of pruning on the annual growth of DBH,tree height and volume of Chinese fir was gradually weakened.After 20 years of pruning,the effect of pruning on DBH,tree height and volume of Chinese fir plantation was not significant.After 20 years of pruning in the middle-aged plantation,there was no significant effect on the total biomass of the Chinese fir stand,but the proportion of stem biomass allocation was significantly increased.The proportion of stem biomass was 14.28%higher than that of non-pruning,and the proportion of leaf biomass allocation was significantly reduced.After 20 years of pruning in middle-aged plantation,the yield and volume of large-diameter timber of Chinese fir plantation were significantly improved,which was conducive to the cultivation of knot-free log of Chinese fir.