原条内部腐朽,多因立木受真菌的侵蚀而形成,也叫先天性腐朽。真菌是一种单细胞植物的有机体。真菌之所以能侵入活立木或伐倒木,是借助于孢子。孢子是很小的细胞,本身很轻,很容易被风送到远处,着落在立术的伤口上而进入立木的内部。当温度、湿度以及空气等条件适宜时,便在那里繁殖,使木材发生腐朽。 Original internal decay, mostly due to the erection of wood by the fungus erosion formed, also known as congenital decay. Fungus is a single-celled plant organism. The reason fungi can invade live or cut down wood is through spores. Spores are tiny cells that are themselves light and easily transported by the wind to the ground, landing on the surgical wound and into the interior of the standing tree. When the conditions of temperature, humidity and air suitable, where they multiply, so that wood decay.