北京东灵山海拔梯度上辽东栎种群结构和空间分布

种群年龄结构和空间分布格局是种群生态学的核心研究内容.为了阐明辽东栎种群海拔梯度分布特点,在北京东灵山地区辽东栎海拔分布范围(1000～1800m)内调查10条样带,研究种群大小级结构和空间分布的变异.种群的平均胸径在海拔梯度上表现出两段式的分布特征,海拔1480m为两段分布的分界点,在每一段内随海拔增加平均胸径也增加, 这反映了海拔梯度上种群的不同发育历史.种群密度、种群的聚集程度、种群的结构在海拔梯度上的分布特征都与平均胸径分布相似,种群密度和聚集程度与平均胸径为负相关系,其分布趋势与平均胸径相反.总体上,东灵山海拔梯度上辽东栎种群还是比较稳定的.辽东栎种群结构和空间分布在海拔梯度上的分布特征是种群发育历史、物种特性、环境、干扰等因素在海拔梯度上综合作用的结果.

Size structure and spatial pattern of Quercus liaotungensis population along elevation gradient in Dongling Mountain, Beijing

Population age structure and spatial pattern are central issues in population ecology. In this study, 10 transects were investigated along altitudinal gradient (1000-1800m) within the distribution range of Quercus liaotungensis in Donglin Mountian to analyzing the altitudinal variation of the population size structure and spatial pattern of Quercus liaotungensis. The results showed that the mean diameter at breast height (DBH) of the population has two variation range along the altitudinal gradient, altitude 1480m is the border of these range. In each altitudinal range, mean DBH increase with altitudinal gradient. This is due to different developing history of each population along altitudinal gradient. Population density, population spatial cluster and population structure are similar with mean DBH along altitudinal gradient. Population density and population spatial cluster are negative related to mean DBH and has decrease trend along altitudinal gradient. The populations along the altitudinal gradient are in stable state in Dongling Mountain, Beijing, China. The paper argued that the altitudinal variation of the population size structure and spatial pattern of Quercus liaotungensis are the synthesis of population history, species traits, environmental, and disturbance along the altitudinal gradient.