Collaborative Research: Wildfire and Mountain Pine Beetle Outbreaks in Subalpine Forests: Cross-Scale Interactions Under Varying Climate

本土树皮甲虫（Dendroctonus spp.）的大规模爆发正在北美洲西部的针叶林中发生，从阿拉斯加西部到美国西南部，据信与气候变暖有关。在科罗拉多州，超过 270,000 公顷的黑松森林最近受到山松甲虫 (MPB) (D. ponderosae) 的侵扰，这引起了公众对甲虫杀死后火灾危险增加的广泛关注。这项研究解决了科罗拉多州北部亚高山森林中野火、爆发和气候相互作用及其潜在跨尺度反馈的四个关键问题。 1) 季节性、年度和数十年时间尺度的气候变化如何影响复杂景观中 MPB 爆发的引发和传播？ 2) 先前的火灾干扰造成的景观异质性如何影响复杂景观中 MPB 爆发的后续干扰的风险和/或蔓延？ 3) MPB 先前干扰造成的景观异质性如何影响复杂景观中的燃料危害和野火风险？ 4) 气候和景观之间特定的突发事件如何影响野火和 MPB 爆发的引发和蔓延？该项目将研究不同空间尺度和不同气候条件下野火和树皮甲虫爆发之间可能的反馈。这项研究和相关的推广活动将增进对甲虫死亡对未来火灾风险影响的了解，这引起了资源管理者、火灾缓解社区和树皮甲虫影响地区公众的广泛兴趣。

Large outbreaks of native bark beetles (Dendroctonus spp.) are occurring throughout coniferous forests of western North America, from western Alaska to the U.S. Southwest and are believed to be related to climatic warming. In Colorado more than 270,000 hectares of lodgepole pine forests have recently been infested by mountain pine beetle (MPB) (D. ponderosae), which has led to widespread public concern about increased fire hazard following beetle kill.This research addresses four key questions about interactions of wildfire, outbreaks and climate and their potential cross-scale feedbacks in subalpine forests in northern Colorado. 1) How does climatic variation at seasonal, annual, and multi-decadal time scales affect the initiation and spread of MPB outbreaks across complex landscapes? 2) How does the landscape heterogeneity created by prior disturbance by fire affect the risk and/or spread of subsequent disturbance by MPB outbreak across complex landscapes? 3) How does the landscape heterogeneity created by prior disturbance by MPB affect the fuel hazard and risk of wildfire across complex landscapes? 4) How do context-specific contingencies between climate and the landscape affect the initiation and spread of wildfire and MPB outbreaks?This project will examine possible feedbacks between wildfires and bark beetle outbreaks across different spatial scales and under varying climatic conditions. The research and associated outreach will improve understanding of the influence of beetle kill on future fire risk, which is of broad current interest to resource managers, the fire mitigation community and the public living in the bark-beetle affected areas.