不同疏伐方法对杉木人工林结构、生长和竞争的影响

Influences of Thinning Methods on structure,Growth and Competition of Chinese Fir Plantations.

本文旨在探讨疏伐方法对杉木人工林林分生长和产量的影响机理。按相对直径将林分划分为３个生长阶层，分析林分的结构、生长速率及竞争状况。结果表明：不同疏伐方法改变了林分结构，影响林分的生长和竞争。机械疏伐林分结构最合理，断面积生长速率和生长量最高，竞争最小。

This paper deals with the principles of the influences of thinning methods on the growth and ylelds of thinned stands.The stands are divided into three growth layers by relative diameter.The structure,the growthrates of basal area and the competition of thinned and unthinned stand are analysed,based on growth layers,The results show that the changps of thestand structure caused by thinning methods lead to the differences of growthand competition among thinned and unthinned stands.The stand thinned inmechanical way has the best structure,the highest growth rate and incrementof basal area and the least competition.