陕北与关中林区草兔危害及发生规律分析

采用野外调查和数学分析的方法,对陕北及关中林区的草兔危害进行了分析。结果表明,在陕北和关中林区遭受草兔危害的面积约为12.61万hm2,平均被害株率6.71%,危害的主要树种有山杏、沙棘、刺槐、侧柏、油松等;同一树种在不同地区的受害程度不同,同一地区不同树种的受害程度也不相同。应用聚类分析法可将调查地区的兔害分成4类,即麟游、耀县、富县为1类,旬邑和千阳为1类,吴旗、安塞和延安为1类,永寿、韩城和潼关为1类;在同一类内,草兔对林木的危害率近似;同时用聚类分析法将调查的9个树种分为3类,即苹果、油松和沙棘为1类,刺槐和仁用杏为1类,侧柏、豆科等为1类。在陕北和关中地区,草兔对林木的危害季节一般均以冬季和早春为主。同时,根据草兔对林木的危害特征,可将其分为剪株型、食苗型、食株型和啃皮型4种。

Analysis of the law and harm of hare to forest in the North of Shaanxi and Guanzhong

This paper analyzes the harm done by hare to forest in the north of Shaanxi and Guanzhong area with field research and statistics analysis.The result shows that the forest damaged by Lepus capensis is 126 100 hm²,and the average rate is 6.71%.The main kinds of trees are Prunus armeniaca,Robinia pseudoacacia,Platycladus orientalis and Pinus tabulaeformis.The harm to the same tree is different in different areas,and the harm in the same area is different with different trees.The season of harm is in winter and early springtime.There are 4 types of harm:snip plant,eat seedling,eat plant and gnaw rind.