天目山针阔混交林中枫香的结构特征

为全面掌握天目山国家级自然保护区针阔混交林中的枫香Liquidambarformosana结构特征，在全面清查基础上设置10个标准地进行林分调查。分析枫香胸径、树高、冠幅结构规律，并运用Weibull分布密度函数分别做拟合对比：利用单株生物量模型测算枫香各径阶、各部分生物量，分析生物量结构；同时研究枫香密度及空间分布格局等结构特征。结果表明：枫香的胸径、树高、冠幅结构符合森林经营的目标，Weibull分布密度函数拟合结果基本符合枫香胸径、树高、冠幅结构规律；树干、树根生物量占枫香总体生物量的91．4％，各径阶枫香生物量总体分布不均匀．树干和树根生物量分布曲线起伏较为接近，各径阶树冠生物量分布较为均匀；各标准地枫香株数密度变动系数为0．625，枫香分布地域差异性较大：各标准地角尺度均值大于0．517，种群内部呈聚集分布。图8表7参20

Structural characteristics of Liquidambar formosana for a mixed coniferous-broadleaf forest in Mount Tianmu

To provide a theoretical construction in a mixed coniferous, basis for Liquidambarformosana protection, broadleaf forest in National Nature Reserve management, and landscape of Mount Tianmu, ten sample plots were established for a stand survey. Diameter at breast height （DBH）, tree height, and crown breadth were studied and fit to a Weibull distribution function. All tree parts and diameter classes of L. formosana biomass were measured using a single tree biomass model, and then analyzed. Density and spatial distribution patterns were also determined. Results showed that DBH, tree height, and crown breadth structure were in accordance to the forest management objectives, and fit the Weibull distribution function well. Trunk and root biomass ac- counted for 91.4% of the total biomass with biomass for all diameter classes being uneven. Distribution curves for trunk and root biomass were similar, and all crown breadth biomass was symmetrical. In all sample plots, variation of the density coefficient for L. formosana was 0.625, and all sample plot means for neighborhood patterns were greater than 0.517. Thus, the density coefficient showed large regional differences in distribu- tion, and neighborhood patterns showed that tree distribution was clumped. Ch, 8 fig. 7 tab. 20 ref.]