Abstract:

This paper deals with the structure and dynamics of pubescent hornbeam population in karst mountain of Guiyang. The results are as follows:

1. The size structures are classified into seven types: initial growing, growing, stational, initial senescent, middle senescent, final senescent and disclimax types. Along with the population and the succession development, the size structure changes mainly from growing, senescent, extremely senescent to residual type.

2. The spatial patterns of the populations are contagious type and random type. Spatial pattern changes with size classes of the population. It was found that the seedling, sapling and small tree classes show contagious types, while the middle and large tree classes exhibit random types. The regularity reflects the dynamic change of spatial pattern with time in development of the population.

3. The population density tends to decrease with the population and the succession development.

4. Pubescent hornbeam population is a pioneer of the karst forest succession on Chinese subtropics, and occurs throughout the succession. But the population at rocky steep slopes or ridges may develope into stationary community.