湿地松人工林间伐效应的研究

Research of Thinning Effect on Slash Pine Plantation

在 8年、 1 2年、 1 6年生湿地松人工林中布设不同间伐强度试验林 ,对不同间伐处理的林分测树因子和间伐作业经济效益进行了分析 ,结果表明 ,间伐对林木生长具有一定的促进作用 ,对幼龄林的促进作用明显大于中大龄林分 ,随着间伐强度增大 ,较大径阶立木株数比例随之增加 ,但期末总收获量减少 ;湿地松人工林首次间伐宜在 1 2年生之前进行 ,保留 90 0～ 1 1 0 0株 / hm2 ,在造纸材销路较好的地区 ,且初植密度较高的林分 ,可在 8年生时进行首次间伐 ,保留 1 4 0 0株 / hm2 ;第二次间伐的间隔期为 6年 ;以培育大中径材为目标的大龄林分应以弱度调整为主 ,保留 60 0株 / hm2 ;另外 。

Some experimental plots with different thinning intensities have been set in 8 year old,12 year old,16 year old slash pine (Pinus elliottii) plantations,and factors of stand with different treatments and thinning effects are analyzed.It is shown that thinning has some promoting effects on tree growth,and the effect on young stand is more significant than on middle aged and elder stands.The proportion of the trees with larger diameter increases and the total harvest of the whole rotation decreases along with thinning intensity.It is suitable to thin slash pine plantation for the first time in the first 12 years,leaving 900～1 100 trees/hm 2,If pulp wood sells well and the orininal density is high,8 year plantation can be thinned when it is 8 years old for the first time,leaving 1 400 trees/hm 2,and the second thinning is carried out 6 years later.If an elder stand is cultivated to yield middle sized and large sized timber,it's density should be adjusted slightly,leaving 600 trees/hm 2.Furthermore,thinning can also improve wood homogeneity of the left trees.