平潭岛木麻黄木毒蛾卵和幼虫空间分布的地统计学分析

Geostatistical analysis on the spatial distribution of eggs and larvae of Lymantria xylina of Casuarina equisetifolia in Pingtan Island

利用地统计学方法分析平潭岛木麻黄基干林中木毒蛾卵和幼虫的空间分布特性,为有效防治其危害提供参考。结果表明:前沿迎风侧木毒蛾的幼虫虫口密度和卵块密度均小于后沿背风侧,木毒蛾幼虫及卵块变异函数在球状模型中均呈现较好的拟合效果。迎风侧和背风侧木毒蛾幼虫种群的空间依赖范围分别为8.6 m和8.7 m,卵块的空间依赖范围分别为8.2 m和6.9 m,空间连续性强度均达到0.92以上,木毒蛾幼虫及卵块均呈聚集性空间分布特征,其空间有显著自相关性,扩散距离范围为6~9 m,这对木毒蛾防治有重要的参考价值。而因受风因素影响,迎风侧距迎风面0~30 m范围内,木毒蛾幼虫及卵块没有明显的聚集性空间分布特征。

The spatial distribution of eggs and larvae of Lymantria xylina in the trunk forests of Casuarina equisetifolia in Pingtan Island was analyzed by using geostatistics method.The results showed:the density of Larva and egg mass of L.xylina on the windward side was lower than that on the leeward side,the variation function of Larva and egg mass of L.xylina presented good fitting effect in the spherical model.The spatial dependent range of the larvae of L.xylina on the windward and leeward sides was 8.6 m and 8.7 m respectively,the spatial dependence range of the egg mass was 8.2 m and 6.9 m,respectively,and the spatial continuity intensity was above 0.92,the spatial distribution of larvae and eggs of L.xylina was aggregative,and there was significant autocorrelation between them.The diffusion distance ranged from 6 m to 9 m,which had important reference value for controlling L.xylina.Because of the influence of wind factors,the larvae and egg masses of L.xylina have no obvious aggregation spatial distribution characteristics in the range of 0~30 m from the windward side.