由于林木生长过程中个体遗传性以及所处环境的不同,引起了林木的分化。林木分化的结果是一部分生长落后的林木衰亡,因此,对随着林龄的增长或森林的生长株数不断减少的现象,称之为林分自然稀疏。林分生长过程表中反映了林分密度株数随着时间的动态变化,亦反映了林龄间单位面积自然稀疏数量。但一树种林龄相同、立地条件(林型、地位级)不同的林分自然稀 Due to the individual geneticity in the process of tree growth and the difference in the environment, the differentiation of forest trees is caused. The result of tree differentiation is the decline of a part of the trees that have fallen behind. Therefore, it is naturally sparsely called for the growing number of trees or the decreasing number of growing forests. The stand growth process table reflects the dynamic change of stand density with time, but also reflects the natural sparse number of units per unit area. However, a species of the same age, site conditions (forest type, status level) different natural thinning stand