Effects of Western Balsam Bark Beetle on Spruce-Fir Forests of North-Central Wyoming
Effects of Western Balsam Bark Beetle on Spruce-Fir Forests of North-Central Wyoming
复制标题
西部香脂树皮甲虫对怀俄明州中北部云杉-冷杉林的影响
DOI：
10.1093/wjaf/18.4.259
复制
发表时间：
2003
影响因子：
--
通讯作者：
J. Negrón
中科院分区：
文献类型：
--
作者：
J. Mcmillin;K. Allen;Daniel F. Long;Jeri Lyn Harris;J. Negrón
在过去的十年中，西部香脂树皮甲虫，Dryocoalphanconfusus（鞘翅目：小蠹科），已造成广泛的死亡率亚高山冷杉（冷杉毛果冷杉）在北美西部。本研究的目的是记录这种死亡率的影响，死亡率与预先存在的林分条件，并调查风暴破坏的冷杉甲虫种群动态中北部的怀俄明州的作用。样带巡航线和对虫害和未虫害的地块安装，以检测森林上层和下层的变化，并确定林分条件和甲虫引起的冷杉死亡率之间的关联。在过去的几年里，甲虫平均杀死了70多棵树。这种死亡率导致显着下降：亚高山冷杉断面积，每英亩的树木，林分密度指数，亚高山冷杉茎在上层的百分比。小，但显着的增加被检测到林下植物，草本植物的丰度增加，在出没的地块相比，noninfested地块。此外，冷杉死亡量与林分中亚高山冷杉树的百分比、亚高山冷杉断面积和亚高山冷杉林分密度指数之间存在显着的正线性关系。此外，一个显着的正线性关系之间的百分比被发现的风造成的倒下的杉木原木在一个地区和木材的百分比利用西方香脂树皮甲虫。20世纪90年代中期发生的排污事件，加上高比例的冷杉成分，为甲虫的持续扩张提供了理想的条件。西方J.应用程序。18（4）：259-266。
Western balsam bark beetle,Dryocoetes confusus (Coleoptera: Scolytidae), has caused widespread mortality of subalpine fir (Abies lasiocarpa) in western North America throughout the past decade. The objectives of this study were to document the effects of this mortality, relate mortality to pre-existing stand conditions, and investigate the role of storm-damaged fir in beetle population dynamics in north-central Wyoming. Transect cruise lines and pairs of infested and uninfested plots were installed to detect changes in the forest overstory and understory and to determine associations between stand conditions and beetle-caused fir mortality. On average, beetles killed more than 70 trees/ac over the last several years. This mortality resulted in significant decreases in: subalpine fir basal area, trees per acre, stand density index, and the percentage of subalpine fir stems in the overstory. Small, but significant increases were detected in the understory; herbaceous plant abundance increased in the infested plots compared with the noninfested plots. Moreover, significant positive linear relationships were found between the amount of fir mortality and the percentage of subalpine fir trees in a stand, subalpine fir basal area, and subalpine fir stand density index. In addition, a significant positive linear relationship was found between the percentage of wind-caused downed fir logs in an area and the percentage of logs utilized by western balsam bark beetle. The blowdown events that occurred in the mid-1990s in combination with a high percentage of fir component has provided ideal conditions for continued beetle expansion. West. J. Appl. For. 18(4):259–266.