浙江省松阳县黄山松种群的密度与生物量动态

 本文研究了浙江省松阳县关山源地区黄山松种群的密度与生物量动态以及它们之间的相互关系。黄山松是该地区森林演替中的先锋种群之一。在演替过程中，黄山松种群的动态可分成三个阶段。大约在黄山松种群入侵次生裸地的最初10年期间，种群的密度和生物量迅速增长(阶段Ⅰ)。此后，种群密度达到饱和，由于自疏作用出现以及其他阔叶树种的入侵，种群密度开始急剧下降，个体平均重量和种群生物量迅速增长(阶段Ⅱ)，–3/2自疏定律适用于种群动态的此阶段。随着阔叶树种进入林冠层，虽然个体平均重量仍缓慢增长，黄山松种群的密度和种群生物量逐渐下降直至退出群落(阶段Ⅲ)。但在一些特殊生境中(如裸岩陡坡或山脊)，黄山松种群可形成稳定的地形顶极群落，其种群密度、个体平均重量和种群生物量可长期维持相对稳定的状态。

DENSITY AND BIOMASS DYNAMICS OF PINUS TAIWANENSIS AT SONGYANG COUNTY,ZHEIIANG PROVINCE

This study was carried out at Guanshanyuan, Songyang County,Zhejiang Province. Density and biomass dynamics as well as their interrelationship for Pinus taiwanensis populations are described. Pinus taiwanensis is one of the pioneer species in forest succession in this region. The analysis of the population dynamics of Pinus taiwanensis throughout the successional process revealed the following three phases.Until ca. 9–10 years after Pinus taiwanensis invades the stands, the density of population is increased by the recruitments along with increase of the mean tree weight and population biomass (phase Ⅰ).Thereafter, the population is in full density state, the biomass of population and the mean tree weight increases exponentially, while the density of population is decreased drastically by the self-thinning and the invasion of other broad-leaved trees (phase Ⅱ). The –3/2 power law of natural thinning is applicable to the population in this phase. When the broad-leaved trees reach the canopy of forest, although the mean tree weight increases slowly, the density and biomass of Pinus taiwanensis population decreases gradually (phase Ⅲ) until the population senesces and retreats from the successional series completely. At some special habitats such as rocky steep slopes and ridges, however, Pinus taiwanensis population can form such an edaphic climax community that the density and biomass of population and the mean tree weight can be in a stable state for quite long period(phase Ⅲ).