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在新疆乌鲁木齐市,对4块不同榆树林地榆跳象(Rnynchaenus dlni Linnaeus)发生程度进行了调查。分别用5种判断空间分布格局的聚集度指标和Talor等回归分析法对榆跳象幼虫的空间分布型进行了研究。结果表明,榆跳象的发生程度与榆树种类之间有明显的差异,在50cm长标准枝上的有虫率为金叶榆>白榆>倒榆>圆冠榆>大叶榆>春榆>裂叶榆,有虫率分别为77.64%、46.91%、24.21%、15.30%、1.41%、1.65%、0.69%。树冠不同层次和方向的受害程度差异显著(P<0.05),树冠中层受害较严重。榆跳象幼虫空间分布型为聚集分布型,并且分布的基本成分为个体群,个体间相互吸引。根据Taylor方法确定了榆跳象幼虫在不同密度下的最适抽样数公式为lgS~2=1.8070+1.7161lgm。
In Urumqi, Xinjiang, the degree of occurrence of four different species of Elm jumping (Rnynchaenus dlni Linnaeus) was investigated. Spatial distribution patterns of Ulva larvae larvae were studied using five kinds of clustering indexes which were used to judge the spatial distribution pattern and Talore regression analysis, respectively. The results showed that there was a significant difference between the occurrences of Ulmus pumila and the species of Ulmus pumila. The rates of the worm on the 50cm long standard branches were as follows: Ulmus pumila> Ulmus pumila> Ulmus pumila> Ulmus pumila> Ulmus pumila> Ulmus pumila Ye Yu, the worm rates were 77.64%, 46.91%, 24.21%, 15.30%, 1.41%, 1.65%, 0.69%. The damage degree of crown at different levels and directions was significantly different (P <0.05), and the middle canopy suffered more serious damage. Ulmus larvae spatial distribution of aggregation type distribution, and the distribution of the basic components of individual groups, individuals attract each other. According to the Taylor method, the optimal sampling number of larvae of Ulmus pumila at different densities is lgS ~ 2 = 1.8070 + 1.7161lgm.