秦岭山地云杉林结构特征与更新动态的研究

STUDY ON THE STRUCTURE CHARACTERIS TICS AND REGENERATION DYNAMICS OF CHINESE SPRUCE FORESTS IN QINLING MOUNTAINS

This paper discusses the mechanism of structure characteristics and dynamics for spruce forest in Qinling Mountains through the investigation and comparison of Chinese spruce( Picea asperata ) forests at different stages.The result shows that there is a large amount of seed sources and a little number of saplings at age below 20 years,but only this species is the dominant regeneration tree species in mature forest of Picea asperata. In the regeneration forest under selection cutting system,the height growth of poplar and birch is very fast during first 30 years,and dominates rapidly over the canopy. Picea asperata shows a lower growth rate and most tolerant tree species in first growth stage so that it will replace gradually all the other trees.After clear cutting,poplar and birch often occur dominant,only a small number of saplings are Picea asperata in the regeneration forest.In nature conditions,it will take a long time to recover the Chinese spruce forests.The amount of saplings and seedlings in the spruce forest is a key factor in the maintain of the steady state of the spruce forest.This dynamics process can be controlled and improved by human activity.