森林天然更新调查的主要内容为单位面积幼树株数及更新频度。这两项调查通常是结合在一起进行的,即在林内系统设置许多方形、矩形、圆形小样方(圆),分别树种、树高级查数小样方(圆)中的幼树。由于幼林分布不均,在成长过程中还要不断自然稀疏,因而只有株数的概念还是不够的,这时频度可以作为反映幼树分布均匀强度的相对性指标。 The main content of the forest natural regeneration survey is the number of trees per unit area and the update frequency. The two surveys are usually carried out together, that is, the system of trees in the forest set up a number of square, rectangular, round sample square (round), respectively, tree species, tree senior check sample square (circle) young tree. Because of the uneven distribution of young forest, but also in the growing process of continuous natural sparse, so only the concept of number of plants is not enough, then the frequency can be used as a reflection of the distribution of young trees relative intensity index.