冀北山地落叶松人工林直径生长与空间结构的关系

The relationship between diameter growth and spatial structure of larch plantation in mountain area of northern Hebei Province

在河北省围场县桃山林场落叶松人工林中选取65组林木,进行大小比数与直径生长关系的分析。基于落叶松(Larix olgensis Henry)人工林固定标准地的每木检尺表数据,针对人工林普遍具有混交度低,分布均匀的特点,主要从林分竞争机制和树冠营养空间利用情况等方面提出了利用Hegyi竞争指数、生长空间指数、生长空间竞争指数分析优化林分空间结构,进一步比较不同择伐程度下林分空间结构变化的大小。结果表明:中心树生长出现两种情况,有明显被压过程和无明显被压过程。林分竞争主要集中在8~15a,是进行抚育间伐的最佳时期,可以为林木提供更大的营养空间,保证林木正常健康生长。

To analysis the relationship between neighborhood comparison and iameter growth,65 groups larch trees ere selected in Tao shan Forest Farm Weichang County,Hebei Province Forestry.The results show that,the center tree grows,two things occur,there had obviously been pressed and had not been obviously pressed.Spatial structure of Larix olgensis plantation was studied based on the pertree survey eata of sampling plot and the common characteristics of low mixture degree and uniform distribution in L.olgensis plantation.In consideration stand competition mechanism and the utilization of the nutrition space of the crown,this article proposed a new method using Hegyi competition index(C1),Growth space indes(GSI)and Growth space competition Indes(GSC)to analyze and optimize the sptial strure.Stand competition focused on 8-15 a,this is the best time for thinning,can provide greater nutritional space to ensure the healthy growth of trees.