Abstract:

An investigation was conducted in plots of the Quercus wutaishanica forests in the Huanglong Mountain of China. The forests were undertaken the close-to-nature management thinning of 13.4% (light thinning) and 30.0% (heavy thinning). An unthinned forest served as the control. The life table, age structure, survivorship curve and spatial distribution were studied in 6 years after the thinning. The results were as follows. 1) The age structure of the population exhibited that seedlings and saplings were predominated, while the young trees were the scarcest. 2) Population mortality rate was the highest inⅠ~Ⅲ age class. With age increasing, the mortality displayed a "high-low-high" mode, while the expectancy life of populations displayed a "low-high-low" mode. 3) The survivorship curve of populations generally matched the Deevey Type Ⅲ. 4) With sampling dimension increasing, the spatial distribution transformed from clumped or random to clump distribution. 5) As the population grew older, their distribution transformed from the clumped into a random distribution while their clumped intensities reduced. 6) Compared with the control, the light and heavy thinning promoted the number of the juveniles and young trees, and population structure was optimized. Therefore, the secondary Q. wutaishanica forest reaches thinning period. Under natural circumstances, the highest clumped intensity at the 25~50 m² was the optimal area for the population regeneration. The close-to-nature management thinning 30.0% was more suitable to the management.

Key words: Quercus wutaishanica, close-to-nature forest management, age structure, life table, survivorship curve, spatial distribution, thinning intensity