突破现行森林抚育技术规程,通过不同强度的抚育采伐+补植经营措施试验,探究抚育经营措施对杉木近熟林生长影响的规律,为优化杉木人工林林分结构、促进杉木人工林全周期经营和大径材培育提供科学依据。以21 a生杉木人工纯林为研究对象,按不同抚育采伐强度设置0%(CK)、20%(T1)、30%(T2)、40%(T3)4个处理,同时补植阔叶树种,各处理3次重复,观察不同处理下杉木和补植树种的生长情况。结果表明,实施抚育经营措施5年间,杉木胸径、树高年均生长量和单木材积、单位面积蓄积年均增长量均表现为T3>T2>T1>CK,各处理差异显著(P<0.05),且随抚育采伐强度增大,杉木林分径阶株数分布曲线峰值向大径阶方向偏移。补植树种花榈木、闽楠、青冈的平均地径、平均树高及地径和树高年均生长量均为T3>T2>T1>CK,各处理差异显著(P<0.05)。高强度抚育采伐(采伐强度40%、保留密度720株/hm²、保留郁闭度0.5)的杉木近熟林生长最佳,3个补植树种中花榈木的生长表现最好。

Through tending management measures test with different thinning intensities and replanting in near-mature forest stands of Chinese fir,breaking through the requirements of the current technical regulations for forest tending,we studied the growth effect rule of different tending measures in near-mature Chinese fir forests,so as to optimize the stand structure transformation and promote full-cycle forest management and large diameter class timber cultivation of Chinese fir plantation forest.With a 21-year-old pure Chinese fir plantation as the research object,four treatments of 0%(CK),20%(T1),30%(T2)and 40%(T3)were set according to the thinning intensity on the basis of the number of trees combined with the replanting of broad-leaved tree species.Each treatment was repeated by three times to observe the growth of Chinese fir and replanted tree species under different treatments.The results indicate that,during five years after tending management measures,all of the average annual growth amounts of the DBH and tree height of Chinese fir,as well as the average annual growth amounts of individual tree volume and growing stock volume per unit area,show the order of T3>T2>T1>CK and the differences among the treatments are significant(P<0.05).Meanwhile,with the increase of the thinning intensity,the distribution curve of the number of trees in each diameter class of the Chinese fir forest stand shifted towards the larger diameter classes.For the replanted tree species including Ormosia henryi,Phoebe bournei,and Cyclobalanopsis glauca,the average ground diameter,average tree height,and the average annual growth amounts of ground diameter and tree height all show the order of T3>T2>T1>CK,and the differences among the treatments are significant(P<0.05).The growth of the nearly mature Chinese fir forest with high-intensity tending felling(felling intensity of 40%,retained density of 720 ind.hm²,and retained canopy density of 0.5)is the best.Among the three supplementary planted tree species,Ormosia henryi shows the best growth performance.