论文部分内容阅读
本文以宁夏银川二代林网中林分和害虫调查资料为基础 ,研究了二代林网主要蛀干害虫——光肩星天牛 (Anoplophora glabripennis Mostch)和木蠹蛾 [Cossus cossus ori-entalis Gaede &H olcocerus vicarius(Walker) ]分别在新疆杨林和刺槐林中因不同的树龄、径粗、林向、郁闭度、林地类型 (林缘和林内 )而呈现出的相应发生特点和为害特性。结果显示 ,新疆杨大于 6年生、胸径超过 1 2 cm径阶受光肩星天牛危害频率高 ;实验用片林林缘到林内 2 m范围内新疆杨受光肩星天牛危害显著高于林内 ,而东、西、南、北 4个方向 ,以东边受害最轻 ;与其它树种组成的混交林林缘同样重于林内。刺槐易受木蠹蛾危害的树龄和径节分别是 6 a～ 1 2 a和 1 2 cm～ 2 0 cm;刺槐片林无论是纯林还是混交林均为林缘重于林内。以上蛀干害虫对树龄和径粗均有较强的一致性选择
Based on the surveys of forest stand and insect pests in the second generation forest of Yinchuan in Ningxia, this paper studied the effects of Anoplophora glabripennis Mostch and Cossus cossus ori-entalis Gaede & H olcocerus vicarius (Walker)] showed the corresponding occurrence characteristics and pest damage characteristics in different forest ages, diameter and diameter, forest orientation, canopy density and woodland types (forest margin and forest) in Xinjiang and Lingeria forests respectively. The results showed that in Xinjiang, the young was more than 6 years old, and the DBH more than 1 2 cm diameter was higher than that of 12 days. , 4 directions to the north, the lightest victims to the east; mixed forest composed of other species and the same edge in the forest. The age and diameter of R. pseudoacacia susceptible to P. xylostella were 6 a ~ 1 2 a and 1 2 cm ~ 2 0 cm, respectively. Both the pure and mixed forests of R. pseudoacacia were more important than those in the forest. The above stem borers on the tree age and diameter have a strong consistency of choice