不同林分杨树云斑天牛种群空间格局地统计学分析

Geostatistical Analysis on Spatial Distribution Pattern of Batocera horsfieldi ( Coleoptera: Cerambycidae) Populations in Different Poplar Forest Types

【目的】研究不同林分杨树林地云斑天牛种群不同虫态的地统计学空间格局,为不同林分杨树林地云斑天牛的防治提供理论指导。【方法】通过调查公路林、片林、渠道林和村庄林4种林分类型的杨树林地,以刻槽、排粪孔和羽化孔为调查指标,确定云斑天牛卵、幼虫、成虫(蛹)的种群数量,利用地统计学方法,研究不同林分不同虫态种群的空间格局。【结果】云斑天牛的刻槽、排粪孔和羽化孔在不同林分杨树林地的拟合模型分别为:公路林均为球形模型,片林均为指数模型,渠道林分别为指数模型、球形模型和高斯模型,村庄林分别为球形模型、指数模型和指数模型。不同林分类型云斑天牛各虫态的拟合半变异函数模型存在差异,但其指的定空间分布格局均为聚集分布。林分类型影响虫口的数量和分布,不同林分类型下各虫态的半变异函数模型和模型参数存在较大差异。云斑天牛危害片林时卵、幼虫和成虫(蛹)的变程a、块金值C_0、基台值C_0+C较其他3种林分类型的统计值明显偏小。【结论】危害杨树云斑天牛种群的卵、幼虫、成虫(蛹)在公路林、片林、渠道林和村庄林中均为聚集分布,即云斑天牛在不同林分杨树林地危害时各虫态的空间分布格局均表现为聚集分布。林分类型与云斑天牛聚集分布的习性关系不大,但影响相应虫态的半变异函数模型和模型参数。

【Objective】In order to provide valuable information and suggestion on controlling Batocera horsfield,an important wood-borer pest,geostatistical spatial distribution of its egg,larva,adult or pupa were studied,when it attacked and damaged severely different poplar forests.【Method】Population size of B.horsfieldi egg,larva,adult or pupa were determined,by the investigating of incisions,frass holes and emergence holes of sampling trees at four forest type plots,including highway forest,patch forest,ditch forest and village forest.Spatial distribution patterns of egg,larva,adult or pupa of B.horsfieldi in different poplar forest types,were analyzed with geostatistical method.【Result】The semivariogram curve models of egg,larva,adult(pupa)of B.horsfieldi in different poplar forest types were as follows.The highway forests were all spherical models.The patch forests were all exponential models.The ditch forests are exponential models,spherical model and gauss model.The village forests were spherical models,exponential model and exponential model.Therefore,it was found that the spatial distribution patterns of the all the models were aggregated,although their models were different in different poplar forest types.The semivariogram curve models and models parameters of B.horsfieldi population in different poplar forest types were obviously different,because poplar forest types effected their population size and distribution.The range(a),nugget(C 0),sill(C 0+C)of egg,larva and adult(pupa)in patch forest plots were less than those of other three type forest plots.【Conclusion】The spatial distribution patterns of B.horsfieldi egg,larva,adult or pupa were all aggregated,when it damaged poplar trees in highway forest,patch forest,ditch forest and village forest respectively.In short,the spatial patters of their different developmental stages in different poplar forest types were all aggregated distribution.There was little correlation between the aggregated behavior and forest types of B.horsfieldi attacking.But forest types effected semivariogram curve models and models parameters of B.horsfieldi population in different poplar forest types.