排序方式： 共有1条查询结果，搜索用时 0 毫秒
1
1.
The change of pine scale (Hemiberlesia pitysophila Takagi) population density on pine forest in urban park between treatment (tending operations) and CK (no tending operations) was researched in this paper. The results were shown as follows: population density declined to 0.63 head per bundle from 2.61 heads per bundle when crown density of pine in urban park had become 0.5 or so by means of cultivation activities such as felling, pruning and thinning and so on, and drop got to 75.86 percent. The pinewoods would soon get revived once using these cultivation activities, so tending operations was main measures controlling over harm of pine scale in urban park; At the same time, population density of pine scale on pinewoods in the sunny slope was more than that in the somber slope and it had become less and less from sunny slope to somber slope. Therefore, tree species must be chosen in the planning and design of urban park for preventing harm and happening of pine scale. 相似文献
1