北京松山自然保护区油松种群生活史及其空间分布格局

Life history characteristics and spatial distribution of Pinus tabulaeformis population in Songshan Nature Reserve of Beijing

该文从生命表特征、年龄结构、存活曲线以及种群不同龄期个体空间分布格局4个方面,研究了松山自然保护区油松种群的生活史动态特征与空间分布规律。结果表明:①油松种群在其生长过程中,当胸径达到22.5cm左右时,由于种内不同个体间为争夺空间与阳光,将遭遇一次死亡高峰;随后将进入一个平稳的生长期,随着龄级的增长,死亡率逐渐升高,直至其衰老死亡。②油松种群的存活曲线基本接近DeeveyⅢ型(曲线凹型)。③油松种群不同龄期个体的分布格局、龄期间的空间关联与尺度有密切的关系,在小尺度上油松各龄期趋于聚集分布,龄期间有较强的关联性;当空间尺度大于临界值时,油松各龄期趋于随机分布,龄期间的空间关联性减弱。

This paper analyzes the life history characteristics and spatial distribution of Pinus tabulaeformis population in Songshan Nature Reserve through four aspects(life table characteristics,age stucture,survival curve,and spatial pattern of individuals in different ageclasses).Results showed that,1)there is a peak of mortality at the DBH of about 22.5 cm,which was caused by intraspecific competition for space and light resource.Then the population will enter a stable growth period,after which mortality increases gradually with ages until they die.2)The survival curve of P.tabulaeformis population generally matches the Deevey TypeⅢ,and the seedlings have a low survival rate due to high crown density.3)The spatial pattern of different ageclasses P.tabulaeformis and the spatial association among individuals depend on spatial scales.In small scales,individuals of all ageclasses P.tabulaeformis tend to clumping distribution,and the spatial association among individuals in different ageclasses P.tabulaeformis is considerably strong.By contrast,if the scales enlarge beyond these points,individuals of all ageclasses P.tabulaeformis disperse randomly,and their spatial association weakens.