2个杉木优良品种不同造林密度效果初探

Preliminary Study on 2 Superior Varieties of Cunninghamia lanceolata(Lamb.)Hook and Their Different Planting Density Effects

以江西红心杉木和福建沙县第2代杉木良种为试验材料,开展不同造林密度(2 500、3 086、3 472株.hm-2)试验。结果表明,在幼龄期2个杉木优良品种生长迅速,树高、胸径、单株材积年均生长分别达到0.98 m、1.4 cm、0.004584 m3以上,且2个良种的生长量和蓄积量没有差异,均可在生产中作为速生良种应用。3种造林密度对2个良种的蓄积量均没有影响,但生长量与造林密度成负相关,在2 500株.hm-2的造林密度下平均生长最优,3 086株.hm-2次之;但从提高单位面积产出及木材形质角度出发,选择3 086株.hm-2的造林密度(株行距1.8 m×1.8 m),可缩短林分郁闭周期,提早进行间伐,节约生产成本,实现杉木商品林小、中、大径材持续利用。

With the materials of Jiangxi red-heart variety and 2nd generation improved variety of Cunninghamia Lanceolata,planting density test which contained the levels of 2500 plants·hm-2,3086 plants·hm-2,3472 plants·hm-2 was carried out.The result showed that these 2 varieties grew fast in the young age stage.The average annual growth of tree height,DHB and volume was at least 0.98m,1.4cm and 0.004584m3,separately.And,there were no differences in growth and volume between the 2 varieties.So,they could be used for plantation as fast-growing varieties.Planting density had no effects on stocking of 2 varieties,but had negative correlation with growth.Under 25 strains hm2 planting density,the average growth was optimal,3086 strains hm-2 was second.But from the aspects of raising output per unit area and wood form quality,the density of 3086 plants·hm2 could be used when the two varieties were used for plantation.It could shorten the canopy cycle and the production costs.So that,the sustainable use of different diameter timber was achievable.