“正态分布标准差分类法”对杉木养分供求响应的研究

通过对杉木树高生长呈“正态分布”的林分，应用“正态分布”标准差作为不同个体生长类型划分临界值，对林分不同生长个体进行分类，探讨不同个体生长类型的年生长量对养分供应的影响。结果表明，杉木树高生长表现类型好的个体，表现更强耐瘠薄能力，树高生长表现类型差的个体，在养分能满足高生长需求量时，同样也有良好的树高年生长量。不同生长表现类型的胸径年生长量对养分供求响应，表明胸径生长表现类型好的个体在养分供应不足时，个体胸径年生长量也不会高，养分充足时胸径年生长量大；生长表现类型差的个体在养分供应不足时，个体胸径年生长量低，而养分供应充足时，个体胸径年生长量接近生长遗传表型好的个体年生长量。该研究揭示杉木不同生长表现类型树高、胸径年生长适应性机理和对养分供应的响应，这对杉木低产林分改良和提高杉木经营水平及林分大径材培育中目标树的选择可提供理论参考。

Application of Standard Deviation Classification Method of Normal Distribution to the Response of Cunninghamia lanceolata for the Nutrient Supply

Taking the Cunninghamia lanceolata stands which presented normal distribution in height growth as research objects,the standard deviation of normal distribution was regarded as the critical index to classify the growth type of individual trees,and to examine the influence of annual growth of the different growth types on nutrient supply.The results indicated that the good height growth group presented stronger adaptability to barren soil,the poor height growth group also showed satisfactory annual height growth when the nutrients were sufficient enough to the height growth.The response of the annual breast-diameter (BD) growth of different growth types for the nutrient supply indicated that the BD annual growth of the good growth group was smaller under insufficient nutrient supply and was higher under the sufficient supply,and the BD annual growth of the inferior growth group was lower under insufficient supply.But the BD annual growth of the inferior growth-group was close to the annual growth of the good growth group under sufficient supply,indicating that the adaptability mechanism and response of the annual height growth and annual BD growth of different growth types.The results would provide theoretical references for improving the existing stands of low-yield C.lanceolata and management of the stands,as well as for cultivating big diameter trees.