植物生态学报 ›› 2004, Vol. 28 ›› Issue (5): 609-615.DOI: 10.17521/cjpe.2004.0081

• 论文 • 上一篇    下一篇

东灵山辽东栎林主要树种种群11年动态变化

侯继华 黄建辉 马克平   

  1. (中国科学院植物研究所植被数量生态学重点实验室,北京100093)
  • 收稿日期:2003-11-26 出版日期:2004-11-26 发布日期:2015-11-03
  • 通讯作者: 侯继华

ELEVEN-YEAR POPULATION GROWTH DYNAMICS OF MAJOR SPECIES IN A QUERCUS LIAOTUNGENSIS FOREST IN THE DONGLING MOUNTAINS, NORTHERN CHINA

HOU Ji-Hua HUANG Jian-Hui and MA Ke-Ping   

  1. (Laboratory of Quantitative Vegetation Ecology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China)
  • Received:2003-11-26 Online:2004-11-26 Published:2015-11-03
  • Contact: HOU Ji-Hua

摘要: 该研究在北京东灵山区一个30 m×40 m的纯辽东栎(Quercus liaotungensis)林永久性样地内进行,林龄为80年左右。样地中高于2 m的成树密度在1991、1997和2002年3次调查中呈逐年递减趋势,这种降低主要是由辽东栎个体的死亡引起的;而树木总胸径面积呈逐年增加趋势,主要是存活个体生长的结果。从1991年到2002年,辽东栎种群的优势度变化不大,且种群径级结构为单峰曲线,差异不显著。为了探讨这种径级分布格局形成的机制,应用离散模型对辽东栎种群的胸径年平均生长率G(t, x)、年平均死亡率M(t, x)及年平均生长率方差D(t, x)进行了计算,发现辽东栎种群的死亡率曲线呈倒J-型,个体的年平均生长率与胸径呈显著的线性正相关(p<0.01)。离散模型的系数分析和G(t, x)-D(t, x)的关系曲线分析均表明辽东栎种群内存在非对称种内竞争,即大胸径个体对小胸径个体的生长有抑制作用,这种作用主要是由相对较高的种群密度引起的对光资源的竞争。非对称种内竞争有利于维持辽东栎种群和整个群落的稳定状态。

Abstract: The population dynamics of major species in a Quercus liaotungensis forest in the Dongling Mountain region, northern China was described based on data from a permanent plot (30 m×40 m) collected over an 11-year period. The age of this forest is about 80 years. The total density of all trees >2 m in height decreased from 1 658 trees•hm-2 (1991), to 1 442 trees•hm-2 (1997) and to 1 400 trees•hm-2 (2002). This decrease in density was mainly due to the death of Q. liaotungensis individuals, which accounted for ca. 75.88%, 72.82% and 67.86% of total density in 1991, 1997 and 2002, respectively. The total basal area increased from 23.48 m2•hm-2 to 27.38 m2•hm-2 over the 11 years, reflecting the growth of surviving individuals. Despite a lack of saplings and new recruits, the Q. liaotungensis had an abundant population of adult trees and exhibited a unimodal size distribution in all three investigations (1991, 1997 and 2002) with no significant differences between them. The patterns of growth, mortality and competition in the Q. liaotungensis population were investigated for individuals>2 m in height, based on the diffusion model. The mortality rate curve, M(t,x), was inverse J-shaped and decreased significantly with DBH up to 10 cm, indicating size-dependent mortality. The mean value of absolute growth rates, G(t,x), was linearly correlated with DBH. The analysis of coefficients in the model and concave relationship of G(t,x) - D(t, x) in Q. liaotungensis population suggested asymmetric intraspecific competition, mainly for the limited light resource due to the relatively high density of the forest. Asymmetric competition might act as a structuring force to maintain the stability of Q. liaotungensis populations and community dynamics.