不同杉木无性系材种结构的差异分析

Comparison of wood assortment structures among different clone Chinese fir plantations

为筛选出适用于定向培育大、中径材的优良无性系,为杉木人工林高效培育精准提供造林材料,选择漳平五一国有林场17年生杉木测定林的39个无性系为研究对象,研究其出材量及材种结构的差异性规律。在野外测定不同杉木无性系胸径与树高的基础上,对树高生长进行拟合,采用最优拟合模型统计各无性系单位面积蓄积量,对实测树高、胸径与单位面积出材量、材种结构材积进行了比较分析。结果表明,不同杉木无性系材种结构差异明显,蓄积量与出材量的差异极显著(P<0.01),出材率受出材量影响显著;选育时可通过对出材量进行聚类及生长量多重对比筛选出符合大、中径材经营的无性系。不同杉木无性系树高拟合模型为H_(i)=2.1979 D_(i)0.6485,在该试验立地条件下,适合大径材培育的7个无性系为M5、M8、M17、M34、M35、M43、M50,其生长量差异不明显,大径材出材量平均值为153.83 m^(3)·hm^(-2),大径材出材率平均值为40.52%;适合中径材培育的无性系为M1、M11、M13、M16、M23、M33、M37,中径材出材量平均值为168.45 m^(3)·hm^(-2),其出材率平均值为55.08%。

The yield and growth of a 17-year-old Chinese fir plantation of 39 clones from Zhangping Wuyi State-owned forest farm was studied to cultivate fast-growing,large diameter Chinese fir.The diameter at breast height(DBH)and tree height(H)of the different Chinese fir clones were measured,and the growth of H was fitted to a model.The optimal fitting model was used to calculate the volume per unit area of each clone.The measured H and DBH were used to determine the timber yield and the timber yield of four kinds of timber structures to analyze the differences reasonably.Results showed that there was a significant difference between the stock volume and timber output of the clones(P<0.01).The timber yield was dominated by the wood output.For breeding,clones suitable for managing large and medium diameter timber were selected by clustering and multiple timber output comparisons.The formula H_(i)=2.1979 D_(i)0.6485 was selected as the H-fitting model for the Chinese fir clones.Under the site conditions,clones M5,M8,M17,M34,M35,M43,and M50 were suitable for large diameter timber management,as their growth differences were imperceptible.The average large diameter timber output was 153.83 m^(3)·hm^(-2),and the average yield of large diameter timber was 40.52%.The clones suitable for medium diameter timber management were M1,M11,M13,M16,M23,M33,and M37,with an average timber output of medium diameter timber of 168.45 m^(3)·hm^(-2),and the average yield of medium diameter timber was 55.08%.