Department of Biological Sciences, University of Alberta, CW 405 Biological Sciences Bldg, Edmonton, AB, T6G 2E9, Canada.
Department of Mathematical and Statistical Sciences, University of Alberta, 632 CAB, Edmonton, AB, T6G 2G1, Canada.
Sci Rep. 2020 May 5;10(1):7601. doi: 10.1038/s41598-020-63388-8.
Mountain pine beetle (MPB) outbreaks have caused major economic losses and ecological consequences in North American pine forests. Ecological and environmental factors impacting MPB life-history and stands susceptibility can help with the detection of MPB infested trees and thereby, improve control. Temperatures, water stress, host characteristics, and beetle pressure are among those ecological and environmental factors. They play different roles on MPB population dynamics at the various stages of an outbreak and these roles can be affected by intensive management. However, to make detailed connections between ecological and environmental variables and MPB outbreak phases, a deeper quantitative analysis on local scales is needed. Here, we used logistic regressions on a highly-detailed and georeferenced data set to determine the factors driving MPB infestations for the different phases of the current isolated MPB outbreak in Cypress Hills. While we showed that the roles of ecological and environmental factors in a forest intensively controlled for MPB are consistent with the literature for uncontrolled forests, we determined how these factors shifted through onset, peak, and collapse phases of the intensively controlled forest. MPB presence mostly depends on nearby beetle pressure, notably for the outbreak peak. However additional weather and host variables are necessary to achieve high predictive ability for MPB outbreak locations. Our results can help managers make appropriate decisions on where and how to focus their effort, depending on which phase the outbreak is in.
山松甲虫（MPB）的爆发给北美的松林造成了重大的经济损失和生态后果。影响山松甲虫生活史和林分易感性的生态和环境因素有助于探测受山松甲虫侵害的树木，从而改善防治效果。温度、水分胁迫、宿主特征和甲虫压力是这些生态和环境因素中的一部分。它们在虫灾的不同阶段对山松甲虫种群动态起着不同的作用，这些作用可能会受到密集管理的影响。然而，要在当地尺度上详细地将生态和环境变量与山松甲虫爆发阶段联系起来，需要进行更深入的定量分析。在这里，我们使用逻辑回归对一个高度详细和地理参考的数据进行了分析，以确定导致柏树丘陵当前孤立的山松甲虫爆发不同阶段甲虫侵害的因素。虽然我们表明，在密集控制山松甲虫的森林中，生态和环境因素的作用与不受控制的森林的文献一致，但我们确定了这些因素如何在密集控制森林的爆发开始、高峰期和衰退期发生变化。山松甲虫的存在主要取决于附近的甲虫压力，特别是在爆发高峰期。然而，要实现对山松甲虫爆发地点的高预测能力，还需要额外的天气和宿主变量。我们的研究结果可以帮助管理者根据爆发阶段做出适当的决策，确定在哪里以及如何集中精力。
