兴安落叶松的结实及其与短枝年龄结构的关系

Fruitage of Larix gmelini and its relation to age structure of short branches.

继1989年以后,1991年大兴安岭林区兴安落叶松又出现一次结实,结实率平均为63.8％,且结实的林木多出现在过火的林地上。胸径28cm以上的林木结实率可达到80％以上,而且结实量多的林木绝大部分(85％以上)是树冠稀疏的。球果多集中于树冠的中部。短枝年龄结构格局对结实具有重要影响。短枝的数量以1、2年生最多,但结实的短枝主要属于3—7年生的短枝,一次种子丰收年,需要消耗大量的短枝数量,花芽中大部分为雄花,直接用于形成球果的雌花,一般尚不足20％。开花结实成熟年龄短枝的存蓄率愈高,其结实的潜力也愈大,出现种子年的可能性也愈大。

Larix gmelini forest at Daxingan Mountains fruited again in 1991 after 1989's fruitage. The average fruiting rate is 63.8％, and most fruited trees are found on burned stands. The fruiting rate of larch trees with a DBH over 28cm is more than 80％, and most of these trees(more than 85％) have a sparse crown. Many fruited cones are mainly located in the middle part of crown. Most short branches are 1-2 years old, but the fruited short branches are 3-7 years old. Every seed year needs to consume many short branches. Most flower buds are male ones, but female flower used for forming cones is only 20％. Therefore, the higher the existing rate of ripe short branch is, the greater the fruiting potential and the possibility of occurred seed year are.