摘要
在 6～ 18年生湿地松、火炬松用材林中布置了 10片间伐强度试验林 ,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 ,最后确定了两个树种工业用材林密度调控方案。正常情况下 ,2 0 0 0株· hm-2以下密度林分 8年生后间伐即有收益 ,而首次间伐龄应在 12年生之前方能使保留木生长速率获得提高。通过间伐可使立木规格材出材率略有提高 ,但伐后 4～ 6 a间 ,立木蓄积量、规格材出材量、林分总收获量基本上随间伐强度加大而减少 ,两次间伐的间隔期至少应在6 a以上。综合考虑立地条件、生长效应和经营目的 ,认为两个树种工业用材林营建应选择立地指数14～ 18林地 ,培育纸浆材林分 ,初植密度 2 0 0 0～ 16 6 7株· hm-2 ,或 15年生主伐 ,或 8～ 10年生作中强度间伐至 12 0 0株· hm-2左右 ,18～ 2 0年生主伐 ;培育建筑材 ,初植密度 16 6 7～ 1111株·hm-2 ,10～ 12年生第 1次间伐至 110 0～ 80 0株· hm-2 ,16～ 18年生第 2次间伐至 80 0～ 50 0株·hm-2 ,2 0～ 2
Thinning density tests were established in 10 plantations of 6～18 years old slash pine ( Pinus elliottii ) and loblolly pine ( Pinus taeda ). Based on the response of stand growth factors to the treatments after 4～6 years and the economic analysis results, the stand density regulating schemes of the two species were determined. According to the the operating results, it is that under the normal conditions, thinning will have net profits in the stands over 8 years old with density below 2 000 trees·hm -2 ,and the time of first thinning must be before 12 years so the growth rate of reserved trees could be improved. By thinning, the outturn percent of merchantable timber of standing trees are slightly increased, bu the growing stock and total yield of stands are decreased along with the increase of thinning density, the interval of thinning should be at least 6 years or longer. With comprehensive consideration of the factors including site conditions, treatment effects and management targets, the cultivation schemes wrer put forward. The establishment of industrial timber plantation with the two species should be on the site with site index of 14～18. For the pulping timber cultivation, the stand should be planted with density of 2 000～1 667 trees·hm -2 , harvested at about 15 years old, or thinned to about 1 200 trees·hm -2 at 8～10 years old and final cut at 18～20 years old. For construction timber cultivation, the planting density should be 1 667～1 111 trees·hm -2 , the first thinning should be operated at 10～12 years old with the reserved trees of about 1 100～800 trees·hm -2 , the second thinning should be at 16～18 years with 800～500 trees·hm -2 reserved, the final cut be at 20～25 years old.
出处
《林业科学研究》
CSCD
北大核心
2000年第4期397-406,共10页
Forest Research
基金
国家造林项目及森林资源发展与保护项目科研推广计划!"国外松速生丰产林培育技术研究与推广"课题的内容
关键词
湿地松
火炬松
工业用材林
间伐
营林制度
slash pine
loblolly pine
industrial timber stand
thinning
cultivation scheme
