抚育间伐对落桦混交林生长过程的影响

Effect of Thinning on Growth Process of Mixed Forest of Larix principis-rupprechtii and Betula platyphylla

为探究抚育间伐对落桦混交林生长过程的影响,选择塞罕坝机械林场的落桦混交林作为研究对象,对其林木的生长变化进行研究,结果表明:落桦混交林经过3次抚育间伐后一定时间内林分的生长率都是增加的,白桦的生长率最高的为第1次抚育间伐后,为20.7%,而华北落叶松生长率最高的为第2次抚育间伐后,为13.5%;林分的3次抚育间伐后生长率都是先增加后减小,并且呈正态曲线变化。抚育间伐后生长空间增大,林分生长速度增加;经过一段时间后生长空间增幅变小,生长速度也随之减小。

In order to explore the effects of thinning on process of mixed forest of Larix principis-rupprechtii and Betula platyphylla,the mixed forest of Larix principis-rupprechtii and Betula platyphylla in Saihanba Mechanical Forest Farm was selected as the research object,and the growth and change of forest trees were recorded by field measurement and analysis of wood.Result shows that:The growth rate of forest stands increased after three times of thinning in the mixed forest.The highest growth rate of Betula platyphylla is 20.7%after the first thinning;the growth rate of Larix principis-rupprechtii after the second thinning is the highest,being 13.5%.After three times of thinning,the growth rate of the stand increase first and then decrease,and it shows a positive curve,indicating that the growth space increased after the thinning,the growth rate of the stand increased,and increase after a period of time.The spatially reduced growth rate also decreases.