抚育间伐对小陇山林区华山松林下植物多样性的影响

Effects of Thinning on the Diversity of Undergrowth of Pinus armandii Plantation in Xiaolong Mountainous Region

为探索不同间伐强度对华山松人工林下植物多样性的影响,在甘肃小陇山林区设置典型样地,以29年生华山松人工林为研究对象,分析弱度间伐(20%)、中度间伐(30%)和强度间伐(40%)林下的灌草丰富度指数、植物多样性指数以及均匀度指数的变化规律,并以未间伐样地作为对照,比较不同样地间的共有种和相似性系数。结果表明:1)随着间伐强度的增大,华山松林下灌草植物种类明显增加,强度间伐林下植物多样性指数和均匀度指数最高;2)阴坡样地的物种丰富度大于阳坡样地,但坡向对林下植物多样性指数和均匀度指数没有显著影响;3)不同强度间伐样地之间有较多的共有种,但与未间伐样地间的相似性系数较低。研究表明,强度间伐能够维持小陇山林区华山松人工林下较高的植物多样性,且以阴坡林下的物种丰富度最大。

In order to explore the effect of thinning intensity on plant diversity of undergrowth of Pinus ar- mandii plantation,the species richness index,diversity index and evenness index of shrub and herbage un- der light thinning （20%） ,medium thinning（30%） and heavy thinning （40%） were investigated taking the un-thinned forest as the control. The typical plots were set in a 29 year-old P. armandii plantation in Gansu Xiaolong Mountainous region, and the common species and similarity coefficient were compared between different areas. The results showed that 1） with the increase of thinning intensity, species of undergrowth increased,and the plant diversity and evenness indices were the highest under heavy thinning intensity. 2） The species richness in shady slope was much greater than sunny slope,but there was no significant influ- ence of slope aspect on the diversity and evenness indices. 3） There were more common species in sample areas after thinning. However,the similarity coefficient in thinned forest was lower than un-thinned forest. As a result, heavy thinning could sustain higher level of plant diversity under P. armandii plantation in Xi-aolongshan forest area,and the species richness in shady slope was the largest.