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本文采用聚集度指标、频次比较及回归分析方法对粗鞘双条杉天牛在杉木人工纯林的为害分布进行了研究.结果表明,粗鞘双条杉天牛在人工杉木林中为害分布属受密度制约的聚集型分布,其临界密度为m_0=2.5961株/样方;受害株的分布以植株群为基本单元,其形成是由于该天牛扩散活动能力弱,产卵范围比较集中所致.根据回归关系式m=0.6280+0.7905m,可确定随机抽样的理论抽样数θ,θ=t~2/D~2((a+1)/X+β+1),以5种不同的抽样调查方法进行比较,结果以棋盘式和平行线抽样调查的结果精确度最高.
In this paper, the degree of aggregation index, frequency comparison and regression analysis of the crude Cunninghamia lanceolata caterpillar adult Cunninghamia lanceolata damage distribution was studied.The results show that the crude Cunninghamia lanceolata cedar artificial distribution in the distribution of harmful species The density distribution was restricted by the density of m_0 = 2.5961 plants / quadrat. The distribution of the affected plants was based on the plant population. The formation was due to the weak dispersal ability and the concentrated spawning range . According to the regression equation m = 0.6280 + 0.7905m, we can determine the theoretical sampling number of random sampling θ, θ = t ~ 2 / D ~ 2 ((a + 1) / X + β + 1) Sampling survey method to compare the results of the checkerboard and parallel sampling survey results of the highest accuracy.