小兴安岭天然针阔混交林主要树种空间格局及其关联性

在小兴安岭天然针阔混交林1.1 hm~2的固定样地内,本文调查和统计了其物种组成和林分径级结构。运用空间点格局分析方法中的O-ring函数,对种群的空间分布格局及其关联性进行分析。结果表明:样地内共有乔木树种15种,重要值排在前四位的依次为红皮云杉(Picea koraiensis)、枫桦(Betula costata)、春榆(Ulmus davidiana)和色木槭(Acer mono),红皮云杉和枫桦属于样地内的优势种,重要值分别为15.81%和11.10%。林下更新状态良好,枫桦的径级结构有呈正态分布的趋势,其余三种均呈现倒"J"形。O-ring函数结果证实,四个主要树种的种群空间分布格局相似,均在0—5 m小尺度上呈聚集分布,随着尺度的增大,逐渐变为随机分布;红皮云杉与其他三个主要种群之间在较大尺度上均呈现显著正相关或无相关,在小尺度上仅与枫桦呈极显著正相关;色木槭在较小尺度上与其他三个种群呈弱负相关性,随着尺度的增大,逐渐变为无相关性。

Spatial point patterns and associations of populations in the coniferous and deciduous broadleaved mixed forest in Xiaoxing'an Mountain

Species composition and populations'' diameter class structure were investigated in a 1.1 hm² permanent plot in the coniferous and deciduous broadleaved mixed forest in Xiaoxing''an Mountain. Using O-ring functions in the spatial point pattern analysis. the populations'' spatial distribution patterns and spatial association are analyzed. The results showed that there were 15 arbor species in the plot. Picea koraiensis, Betula costata, Ulmus davidiana, and Acer mono ranked as the top 4 important species in our plot. Picea koraiensis and B. costata were the major dominant species with importance values of 15.81% and 11.10%, respectively. This forest was also founf to be in good regeneration condition. The size class structure of B. costata tended to be normally distributed, while that of the other three populations showed an inverted "J" shape. The results from the O-ring function showed that the spatial distribution pattern of the four main populations was similar, with distributions was aggregated at the 0-5 m scale. At increasing scales, distributions shifted from aggregated to random. Picea koraiensis had a significant positive or no correlation with the other three main populations at coarse scales, but only had a significant positive correlation with B. costata at fine scales. Acer mono had a non-significant negative correlation with the other three populations at fine scales. As the scale increased, no correlation was found.