Size structure and spatial pattern of Quercus liaotungensis population along elevation gradient in Dongling Mountain, Beijing
北京东灵山海拔梯度上辽东栎种群结构和空间分布

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.