【摘要】 采用4块100m×100m的天然林样地材料,根据不同样地大小对应林木的株数和断面积来估算其每公顷株数和断面积,计算估计值与实际值的差异;并分别利用角尺度和双相关函数分析不同大小的样地对应林木个体的空间分布格局。结果表明,无论非空间结构指标还是空间结构指标都与样地大小有关。随着样地面积逐渐变大,所估计的每公顷密度和分析的林木空间分布格局均趋于稳定,这意味着林分的密度估计和结构分析必须在足够大的样地上进行。根据本研究资料,当样地面积为2500m2时,无论是对密度估计还是结构分析都是合适的。更多还原

【Abstract】 Data from 4 100 m×100 m natural forest plots were used to estimate tree number per hectare and basal area based on plot sizes, the difference between estimated and actual values was calculated. Then a uniform angle index and a pair-correlation function were used to analyze the spatial patterns of trees in forest plots with varying sizes. It is shown that both the spatial and non-spatial structure indices of forest are related to plot sizes. Both densities and patterns become stabilized with increasing plot sizes, indicating that stand densities and forest patterns should be estimated or analyzed with data from big enough plots. According to our study, 2500 m2 is appropriate for either the estimation of stand densities or analysis of forest patterns.更多还原