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利用浙西天目山常绿阔叶林样地调查数据,在随机样方点格局分析基础上,提出样方形状对点格局分析性能影响差异性问题。结果表明:(1)在最优样方面积相同条件下,通过配对t检验得出圆形与正方形、圆形与正六边形和正方形与正六边形样方性能对比的配对t检验概率P分别为0.249、0.043和0.023,表明样方形状对点格局分析性能影响具有差异性,圆形样方和正方形样方之间没有显著差异,正六边形样方与圆形样方、正方形样方之间差异显著;(2)圆形～正六边形和正方形～正六边形样方间VMR差值的95%置信区间分别为[-0.429,-0.010]和[-0.196,-0.021],其区间值上界均小于0,表明正六边形样方分析性能为最优,其性能高于圆形样方和正方形样方;(3)随机样方法在样本量较小时,点格局分析结果不稳定,但随着采样数目逐步增大到90以上时,其VMR值和P值趋于稳定。
Based on the survey data of the evergreen broad - leaved forest in Tianmu Mountain, western Zhejiang Province, on the basis of stochastic plot pattern analysis, this paper presents the difference of the influence of quadrat shape to the point pattern analysis. The results show that: (1) Paired t-test results show that the paired t-test results of paired t-square test are the same for round and square, round and regular hexagon, square and regular hexagon Which is 0.249, 0.043 and 0.023, respectively, indicating that the square shape has a different effect on the performance of the point pattern analysis. There is no significant difference between the square sample and the square sample. The regular hexagon sample, the square sample, the square sample sample, (2) The 95% confidence intervals of the VMR difference between the circular-hexagonal and square-hexagonal quadrats are [-0.429, -0.010] and [-0.196, -0.021], respectively. The interval The upper bounds of the values are all less than 0, which indicates that the performance of regular hexagonal quadrats is the best, and its performance is higher than those of round and square quadrats. (3) When the sample size is small, the result of point pattern analysis is unstable , But as the number of samples gradually increases above 90, the VMR and P values tend to be stable.