关帝山华北落叶松天然更新种群结构与空间格局研究

华北落叶松（Larix principis—rupprechtii）是分布于华北山地半湿润地区针叶林的主要建群种之一。从种群的大小级结构、空间分布格局及动态等方面，研究了关帝山采伐迹地上华北落叶松天然更新种群的数量特征与空间格局。结果表明：（1）华北落叶松幼苗幼树缺乏，2．5cm〈DBH≤17．5cm的个体数量丰富，DBH〉17．5cm个体数量稀少，种群表现为衰退型，但华北落叶松较长的生命周期、数量丰富的中小径级个体和客观存在的林冠干扰，使得其依然可发展成为稳定的种群；（2）采伐迹地上华北落叶松幼苗幼树多为集群分布；2．5cm〈DBH≤7．5cm的林木在2m×2m的尺度下呈显著的集群分布，而随取样尺度增大，聚集性减弱，趋于随机分布；7．5cm〈DBH≤17．5cm的林木在各个取样尺度基本上呈随机分布，这与其自身的生物学特性和环境光照条件密切相关。

Population Structure and Spatial Distribution Pattern of Natural Regeneration Larix principis-rupprechtii in Guandi Mountain

Larix principis-rupprechtii is one of main constructive tree species of conifer forest which is distributed in semi-humid region, north China. The population structure and spatial pattern of different size classes were studied in a natural regeneration stand which lies in a clear-cut strip. The results revealed that Larix principis-rupprechtii population trends decline for the shortage of seedling and sapling. But the population has the potential to be stable in respect that long life span, abundant trees of middle size class and disturbance. The seedlings and saplings were clumped. Trees of 2.5 cm 〈 DBH ≤ 7.5 cm were clumped under the scale of 2 m × 2 m, whereas which trended to distribute randomly with the scale increasing. The others were randomly distributed. We concluded that the current distribution pattern of Larix principis-rupprechtii was related to itself biological characteristics and light.