杉木建材林初植密度幼龄期效应的研究

Study on the effects of primary planted density of young trees of the construction timber forest of China fir

在宁镇丘陵地区的句容市３个国营林场，选用广西融水优良种源，采用３３３０～１６６５０株／ｈｍ２的１１种初植密度营建杉木短轮伐建材林，探讨不同密度对椽材（小条木）和小径材生产的效应。结果表明，初植密度对树冠、胸径、树高、高径比、幼林蓄积、地上部份生物量及其分配均有显著的影响。但对幼林木材基本密度（６年）影响不明显。３３７０～５５５０株／ｈｍ２造林密度是该地区短轮伐期小径材作业适宜的初植密度，可望８年间伐椽材，１２～１４年生产出小径材。９９９０株／ｈｍ２以上密度不经间伐很难在８～９年生产出椽材，不宜作为椽材作业的初植密度。

he study selected the Rongshui provinance,Guangxi provinance as the elite China fir(Cunninghamia lanceolata Hook.) provinance and 11 kinds of prelimeary planted density is 3330￣16650 plants/hm 2 as the short period cutting for construction timber forest.And discussed the effects of young primary density of trees for culture rafter and small diameter lumber in the hill area of three state forest farm Jurong city.The research results showed there are significant effect of primary density of trees on the crown,breast diameter,tree height,the rate of height and diameter,volume of young tree,biomass above ground and its distribution.There isn't notable effect to the basic density of young forest (6years old).The most suitable primary density of young fir is 3370￣5550 plants/hm 2 in the hill area of short period cutting for small diameter timber.It is very hopeful of 8 years old thining for the use of rafter and 12￣14 years old cutting for the use of small diameter timber.Above 9990 plants/hm 2 it is very diffcult to produce rafter in 8￣9 years and its primary density of China fir cann't use in culture of rafter lumber.