Performance efficiency comparison and analysis of spatial point patterns with different shapes of quadrats: A case study of the evergreen broad-leaved forest in Tianmu Mountain
样方形状对空间点格局的性能影响分析——以天目山阔叶林为例

Based on spatial point pattern and survey data of the evergreen broad-leaved forest in Tianmu Mountain,West Zhejiang Province,we come up with a question about how quadrat shape affects performance efficiency of spatial point pattern.The research results are shown as follows.(1) In the same area of optimal quadrat,the probabilities are 0.249,0.043,and 0.023 between round quadrat and square quadrat,between round quadrat and hexagon quadrat,and between square quadrat and hexagon quadrat with paired-T test.It is indicated that quadrat shape significantly affects performance efficiency of spatial point pattern,and there is no significant difference between round quadrat and square quadrat,and there is significant difference between hexagon quadrat and round quadrat or square quadrat.(2) The 95% confidence intervals of the VMR difference between round quadrat and hexagon quadrat,square quadrat and hexagon are-0.429,-0.010] and-0.196,-0.021],the ceiling of the intervals is less than 0,indicating that hexagon quadrat is the best performance quadrat,and that its performance is much higher compared with round quadrat and square quadrat.(3) When the sample size is small in random quadrat analysis methods,random quadrat analysis results are unstable,but with the sampling number exceeding 90,the VMR(Variance-Mean Ratio) and P value remain stable.