关键词: 黄曲条跳甲, 印楝素, 生态控制, 忌避作用, 害虫累积为害量

Abstract: Ground surface dead fuel moisture content in forests is closely related to forest fires. To understand this moisture content and its relationship with environmental factors is of great significance in wildfire management. In this paper, the ground surface dead fuel moisture content in different forest types in Huzhong area of Great Xing’an Mountains was investigated, according to the classification standard of 1, 10, and 100 h. The results showed that Betala platyphlla-Populus davidiana forest and Chosenia arbutifolia forest had higher dead fuel moisture contents than the other forest types, but no distinct difference was observed in the other forest types. Among different Larix gmelinii forest types, Vaccinium vitis-idaea-Larix gmelinii forest had a higher dead fuel moisture content than the rest Larix gmelinii forest types, but there was no obvious difference as well. The detrended canonical correspondence analysis (DCCA) on the environmental gradient of ground surface dead fuel moisture content indicated that the first axis reflected the spatial gradients of altitude and topographic position, i.e., temperature condition, while the second axis reflected the gradients of aspect and stand density, i.e., humidity condition. Generally, the main factors affecting the spatial pattern of ground surface dead fuel moisture content in forests were altitude and topographic position. The two-dimensional plots of axis 1 and axis 2 could clearly express the spatial gradient of ground surface dead fuel moisture content in Huzhong forest area of Great Xing’an Mountains.

Key words: Striped flea beetle, Phyllotreta striolata(F), Azadirachtin, Ecological control, Deterrent effect, Insect pests accumulated damage amount