前言首先使赤松幼树高密度生长,是赤松天然更新获得成功的首要条件,至少每公顷必须有5万株以上的幼树。实际上每公顷生长10万株以上的幼树的更新地也不少,一开始就成了高密度状态。相反,如果这种高密度一直继续下去,随着生长进一步变得过密,对雪和风的抵抗力变弱,将会产生倒伏,林分终于受到破坏。因此,在赤松天然更新地,为了适应赤松的生长,使生长株数逐渐减少的密度管理作为初期的抚育作业是很重要的。 Foreword First of all, the growth of saplings of redwood trees at a high density is the prerequisite for the success of the natural regeneration of the redwoods. There must be at least 50,000 saplings per hectare. In fact, more than 100,000 trees per hectare of saplings are not less developed and have become densely populated at the outset. On the contrary, if this high density continues, the stand will eventually be destroyed as the growth further becomes overly dense and the resistance to snow and wind becomes weaker. Therefore, in the natural regeneration of Japanese red pine, in order to adapt to the growth of Japanese red pine, the number of growing plants is gradually reduced as the density management as an initial tending operation is very important.