张华香+汪洋+冷艳芝+杨旭+尹茜

摘要：对九宫山保护区惟一红椿（Toona ciliata Roem.）群落设立2个样地，研究了T1和T2样地种群空间分布格局。通过龄级划分研究种群年龄结构和动态量化分析，以探讨不同样地红椿种群空间结构与分布格局的成因。结果显示，2个样地的种群分布格局在16、25、50、100 m2时，均为泊松分布；取样面积越大，Lloyd平均拥挤度（m*）和丛生指数（I）越大；T2样地的Lloyd平均拥挤度（m*）和丛生指数（I）值均高于T1样地。T1和T2样地Ⅰ龄级数量分别占总量的41.86%和48.18%，Ⅳ、Ⅴ龄级环境筛与竞争作用加强。2个样地种群动态指数变化差异较大，T1样地为10个龄级，VⅣ、VⅤ、VⅥ为波动；T2样地12个龄级，VⅣ、VⅤ、 VⅨ、VⅩ为波动。2个样地种群Vpi1=40.83 %，V′pi1=2.041，Vpi2=49.72%，V′pi2=4.144，均属于增长性种群，天然更新较好，但种群老龄化趋势明显。因此，加强森林抚育，人为制造林窗，将更有利于红椿种群的更新和稳定发展。

关键词：红椿（Toona ciliata Roem.）；种群结构；空间分布格局；九宫山

中图分类号：S792.33+5（634TS） 文献标识码：A 文章编号：0439-8114（2017）14-2685-05

DOI：10.14088/j.cnki.issn0439-8114.2017.14.022

Abstract： 2 sampling plots were set up to research the spatial distribution pattern of Toona ciliata Roem. population. The structure of age class and quantitive dynamic indexes were analyzed to identify the causes of structure and distribution patterns of T. ciliata populations in the Jiugong Mountain Region. The result revealed that the distribution pattern in 16 m2， 25 m2， 50 m2 and 100 m2 grid were all Poisson distribution. Both the David & Moore's cluster index（I） and mean crowding index（m*） increased with the sampling size； and the 2 indexes of T2 sampling plot were higher than those of T1. The quantities of the Ⅰ age class accounted for 41.86% and 48.18% of the 2 plots， respectively； while environmental sieves and competitive effect intensified in Ⅳ to Ⅴ age classes. Population dynamics index of the 2 plots changed a lot. T1 plot has only 10 age classes， fluctuated negatively in VⅣ， VⅤ and VⅥ， with Vpi1=40.83% and V′pi1=2.041； T2 plot has 12 age classes， waved negatively in VⅣ， VⅤ， VⅨ， and VⅩ， with Vpi2=49.72% and V′pi2=4.144. Both the plots were growing populations with good natural population regeneration； but the aging tendency was evident. Therefore， the intensification of woods tending， and canopy gaps interfered by human management are conducive to the regeneration and balanced development of the population.

Key words： Toona ciliata Roem.； population structure； spatial distribution pattern； Jiugong Mountain

種群是构成群落的基本单位，种群分布格局能够反映种群空间变化规律，体现种群动态及其群落的演替趋势[1]，研究种群空间格局对于分析和发现濒危植物的致危因素具有重要价值。由于种群分布格局是种群生物学特性、种内种间关系及环境条件综合作用的结果，是种群的基本数量特征之一[2]，因此研究种群分布格局的目的不仅是对种群水平结构进行定量描述，更重要的是用以揭示格局的成因，阐述种群及群落的动态变化，为种群保护措施的制定提供一定的科学依据[3，4]。然而种群格局研究受取样面积的影响，在不同尺度上考察所得到的结论不同[5]。……