摘要
1988年在大兴安岭火烧迹地上,调查了云杉小黑天牛(Monochamus sutor L)幼虫的空间分布。采用扩散系数(C),Iwao的m—m回归分析如Taylor幂的法则等7种方法,测定云杉小黑天牛幼虫的空间分布型呈聚集分布,分布的基本成分是个体群。扩散蔓延规律为聚集型扩散。其聚集程度随火烧程度、有虫株率及虫口密度大于5～7个侵入孔/1000 cm^2时种群趋于随机或均匀分布。聚集原因分析表明,平均1000 cm^2树干面积上2.13头幼虫是该虫种群聚集机制发生变化的临界值。
Monochanns sutor L. is one of the most dominant stem borers in burned area of Great Xing An Mountain. The spatial distribution pattern of its lavae belongs to aggregation distribution. The dispense rule of population is aggregated pattern,and the aggregated degree vary as intensity of fire,percentage of attacked trees with this pest and population density. When the attacked trees is near 100%,and the density is greater than 5～7 larvae/1000 cm^2,the distribution tend foward a random or uniform pattern. According to analysis for aggregation reasons,we know that the threshold hanging aggregating mechnism of the population is 2.13 larvae/1000 cm^2.
关键词
云杉
小黑天牛
火烧迹地
空间分布
Monochamus sutor L
Burned Area
Spatial Distribution
