检索规则说明:AND代表“并且”;OR代表“或者”;NOT代表“不包含”;(注意必须大写,运算符两边需空一格)
检 索 范 例 :范例一: (K=图书馆学 OR K=情报学) AND A=范并思 范例二:J=计算机应用与软件 AND (U=C++ OR U=Basic) NOT M=Visual
作 者:杨桦[1,2] 杨茂发[1] 杨伟[2] 杨春平[2] 董杰超[2] 沈远华
机构地区:[1]贵州大学贵州山地农业病虫害重点实验室,贵阳550025 [2]四川农业大学森林保护重点实验室,四川雅安625014 [3]名山县林业局,四川名山625100
出 处:《四川农业大学学报》2010年第2期148-152,共5页Journal of Sichuan Agricultural University
摘 要:应用聚集度指标法、回归分析法对危害南抗杨的云斑天牛幼虫种群空间分布格局进行研究。结果表明,云斑天牛幼虫在桦树林内呈聚集型分布状态,分布的基本成分为个体群,个体之间相互吸引又保持一定的排斥距离;根据距离干基部的不同位置划分为3个高度,得出不同高度的虫口数量在5%水平达显著差异,且1 m以下的虫口数量最大;云斑天牛刻槽数量与胸径大小和树高的关系中,胸径大小对刻槽数量作用率高;从树皮厚度与刻槽数量关系中可以看出3.6~4.0 mm范围内刻槽数量最多,而在单位体积的树干内,虫口密度越小其生息坑道的面积和长度越大。The aggregation index method and regressive model analysis method were used to make a study on the spatial distribution pattern of the larvae of Batocera horsfieldi which do harm to Populus delteides.cv.nankang.The results showed that the spatial distribution pattern of the larvae of Batocera horsfieldi(Hope) accorded with assemble distribution type in the Populus forest,and the basic distribution component was individual colony.Within each colony,the individuals attracted each other and kept maintaining certain repel distance.Significant difference existed at the level of 5% in the quantity of the pests at different positions if three different positions away from the base of trunk were divided.What's more,the number of the pests would be a maximum from 1 m down to zero.In the relationship between the number of gnawing nidus and DBH size and height,the DBH size greatly affected the number of gnawing nidus of Batocera horsfieldi(Hope).In the light of the relationships between the thickness of the bark and the number of gnawing nidus,it was found that the number of gnawing nidus reached the maximum when the thickness of the bark was from 3.6 mm to 4 mm.In the trunk per unit volume,the smaller the population-density of the pests was,the larger and the longer the area and the length of their living-inhabiting tunnels are.
分 类 号:S763.38[农业科学—森林保护学]
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在链接到云南高校图书馆文献保障联盟下载...
云南高校图书馆联盟文献共享服务平台 版权所有©
您的IP:216.73.216.7