二化螟种群空间格局的经典分析与地统计学比较研究

为揭示二化螟幼虫空间格局特征并阐明经典格局分析的局限性与地统计分析的优越性，从2个原始样本出发，另构建了一系列格栅样本、随机样本和顺序样本并进行了比较研究。结果表明，经典格局分析不能有效区分频次分布相同但分布型或聚集程度不同的样本，存在受样方大小、格栅初始点位置和样本容量大小影响等许多局限性，其中受格栅初始点位置影响是首次报道；而地统计学半变异函数能有效刻划二化螟种群空间分布格局，表征其聚集强度和空间异质性，且受样方大小、格栅初始点位置和样本容量大小的影响较小，二化螟种群在低密度下呈随机分布；在高密度下呈聚集分布，聚集强度为0．1056，空间依赖范围为193cm，在高密度下二化螟种群空间分布存在几何异向性，行方向上的聚集强度（0．2716)明显高于列方向(0．0867)，但行方向上的空间依赖范围(115cm)小于列方向(264cm)。

Spatial distribution pattern of Chilo suppressalis analyzed by classical method and geostatistics

Two original samples of Chilo suppressalis and their grid,random and sequence samples were analyzed by classical method and geostatistics to characterize the spatial distribution pattern of C.suppressalis.The limitations of spatial distribution analysis with classical method,especially influenced by the original position of grid,were summarized rather completely.On the contrary,geostatistics characterized well the spatial distribution pattern,congregation intensity and spatial heterogeneity of C.suppressalis.According to geostatistics,the population was up to Poisson distribution in low density.As for higher density population,its distribution was up to aggregative,and the aggregation intensity and dependence range were 0.1056 and 193 cm,respectively.Spatial heterogeneity was also found in the higher density population.Its spatial correlativity in line direction was more closely than that in row direction,and the dependence ranges in line and row direction were 115 and 264 cm,respectively.