【摘要】 [目的 ]阐明立地、初植密度、林龄、林分密度、竞争指标等因子与大径材成材的关系，解析杉木大径材形成机理，为杉木大径材定向培育提供理论和技术支撑。[方法 ]利用福建省邵武市卫闽国有林场40余年杉木长期定位观测试验林数据材料，解析立地、初植密度、林龄、林分密度、竞争指标等因子对杉木大径材形成的影响。[结果 ]大径材出材量和出材率随立地指数级增大而增大，且增幅效应随林龄而增强。立地对大径材成材的影响程度明显受到初植密度的作用，低密度更有利于立地作用的发挥。12～16指数级立地，初植密度对大径材出材量和出材率影响较小，且大径材出现林龄较晚；20～22指数级立地，初植密度作用明显加强，大径材出材量和出材率随初植密度减小而增大，初植密度越小，大径材形成时间及大径材快速增长启动林龄愈早，且主伐林龄越小。林龄、立地、初植密度两两之间存在显著的交互作用。在相对低立地指数级范围（12～16指数级）或高立地指数级范围（20～22指数级）内，大径材出材量或出材率不受立地指数级的显著影响，而当立地指数级达到或超过20指数级后，其与相对低的指数级（12～16指数级）立地相比，则会显著提高大径材出材量。在中、高初植密度范围(3 333～6 667株·hm^-2或5 000～10 000株·hm^-2)内，杉木林分大径材出材量或出材率不受初植密度的显著影响，但其与低初植密度(1 667株·hm^-2)林分相比，大径材出材量或出材率则会受到初植密度的显著制约。林龄、林分保留密度、林分密度指数、立地指数为大径材成材的关键因子，其对大径材形成的加成贡献率达92%。[结论 ]14指数级的现实林分中，有部分林分可形成相当数量的大径材。16指数及以上立地是培育杉木大径材的理想立地条件，且造林密度宜控制在1 667株·hm^-2内，16指数在40年生左右，20和22指数在28年生左右，可形成大径材林分，出材率达50%以上，出材量至少达400 m3·hm^-2左右。更多还原

【Abstract】 [Objective] This study clarify the relationships between factors including site, initial planting density, stand age, stand density, competition index and large-diameter timber and analyze the formation mechanism of large-diameter timber of Chinese fir in order to provide a theoretical and technical support for the oriented cultivation of large-diameter timber in Chinese fir. [Method] Using the data from the longterm experiment of Weimin state-owned forest farm in Shaowu, Fujian province over 40 years, the effects of site, initial planting density, stand age, stand density, and competition index on the formation of largediameter timber of Chinese fir were examined. [Result] The outturn and outturn rate of large-diameter timber increased with the increase in the site class. The initial planting density clearly affected the effects of the site on the outturn of large-diameter timber, and low planting density were more favorable to the site effect. The initial planting density had a minimal impact on the outturn and outturn rate of large-diameter timber at site classes of 12 to 16, and the formation age of large-diameter timber was late. The large-diameter timber in the stands of 20～22 site classes was much more affected by initial planting density, and the outturn and outturn rate of large-diameter timber increased with the decrease in initial planting density. Low planting densities led to earlier time of producing large-diameter timber. There was a significant interaction among the stand age, site index and initial planting density. The outturn and outturn rate of large-diameter timber was not significantly affected by site class in the relatively low site index（12～16） or high site index（20～22）, but when site index reached or exceeded the 20 site class, the large-diameter timber outturn would be significantly increased compared with low site classes（12～16）. Large-diameter timber was not significantly affected by initial planting density in the ranges(3 333～6 667 trees·hm^-2 or 5 000～10000 trees·hm^-2). However, initial planting density significantly reduced the outturn and outturn rate of largediameter timber when compared with the low initial planting density(1 667 trees·hm^-2). The key factors affecting large-diameter timber were stand age, stand density, stand density index, and site index, and their combined addition contribution rate was 92%. [Conclusion] Some stands in the site class of 14 maybe produce large-diameter timber. The ideal site condition for producing large-diameter timber was more than the site index 16. Planting density should be smaller than 1 667 trees·hm^-2, and the large-diameter timber stand can be formed in about 40 years for site class of 16 and 28 years for site classes of 20～22, with an outturn rate of more than 50% and timber outturn of at least 400 m3·hm^-2.更多还原