The spatial distribution and size class of Quercus liaotungensis, a deciduous canopy species, was studied in two warm temperate deciduous forests (ca. 50 and 30-year-old) in Northern China. Pattern of spatial dispersion varied with size class and the scale of observation. In the 50-year-old forest, the most clumped distribution appears in the tall saplings (1 to <2 m in height) and in the order of short saplings (0.4 to <1 m in height), seedlings (less than or equal to 0.4 m in height) and adults (greater than or equal to 2 m in height). The class distribution of Q. liaotungensis was nearly a reverse-J shape for the 50-year-old forest, suggesting that the population regenerates continuously. In the 30-year-old forest, as for the class from seedlings to saplings, the most clumped distribution appear in the seedlings, followed by the short saplings acid tall saplings. The class distribution indicates that the population does not regenerates continuously, probably due to the high tree density. These results suggest that managing forest with some disturbance (e.g. selective cutting) is more beneficial for forest regeneration than protecting without any human activities.
