"Understanding the interactions between climate, forest management and the effects of insect outbreaks on the boreal forest"

气候变化和森林采伐造成的生态系统结构的大规模改变正在影响诸如虫害暴发等自然干扰。我的研究项目将评估气候和森林管理对过去和现在昆虫爆发的相互作用。云杉budworm （SBW）将受到特别关注，因为加拿大东部开始爆发新的疫情。在短期内，我将评估造林假设，即森林管理可以通过改变树种组成来减少（或相反地放大）SBW爆发的影响。这是树木多样性在减少昆虫食草性影响方面的作用的一般理论的一个具体案例。目前的研究还表明，昆虫爆发的影响不仅受到林分组成变化的影响，还受到开口、幼林和成熟林景观格局的变化以及气候变化影响的森林与爆发昆虫之间相互作用的影响。具体来说，(1)我将评估当它们由系统发育上相距较远的树木组成时，混合树种林分的保护作用，以及是否由于关联易感性或从更偏好的宿主到更不偏好的宿主（如黑云杉）的“溢出”而存在更大的脆弱性。作为第二个具体目标，(2)我将从寄主配置的角度评估森林管理遗产对当前和最近过去云杉budworm爆发发展的影响。在气候方面，目前的疫情主要发生在过去两个世纪观察到其主要影响的北部地区。因此，另一个短期目标(3)将是评估具有相似成分但位于不同地理位置（即纬度和气候梯度）的林分如何响应SBW。目前有证据表明，最近爆发的一些昆虫物种已经扩大了它们的活动范围，并对森林造成了严重的破坏，但这些可能会被其他害虫造成的破坏减少所补偿。因此，最后(4)，我问气候和林业是否扩大了北美主要森林害虫的爆发？

Climate change and large scale modifications to ecosystem structure due to forest harvesting are influencing natural disturbances such as insect outbreaks. My research program will evaluate the interaction between climate and forest management on past and current insect outbreaks. The spruce budworm (SBW) will receive a particular focus as a new outbreak is beginning in eastern Canada. In the short-term, I will evaluate the silvicultural hypothesis that forest management can reduce (or conversely amplify) the effects of SBW outbreaks by modifying tree species composition. This is a specific case of the general theory of the role of tree diversity in minimising the effects of insect herbivory. Current research also suggests that the effects of insect outbreaks are not only influenced by modifications of stand composition but also by modifications to landscape patterns of openings, young forest and mature forest and by the climate change influenced interactions between forests and outbreaking insects. Specifically, (1) I will evaluate the protective effects of mixed species stands when they are composed of phylogenetically distant trees versus whether there is greater vulnerability due to associational susceptibility or 'spill-over' from more preferred hosts to less preferred hosts such as black spruce. As a second specific objective, (2) I will evaluate the effect of forest management legacies in terms of host configuration on the development of the current and most recent past spruce budworm outbreak. Climatically, the current outbreak is mainly occurring north of where its major impacts have been observed over the last two centuries. Another short term objective (3) will thus be to evaluate how stands with similar compositions but at different geographic locations (i.e. a latitudinal and thus climatic gradient) respond to the SBW. Currently there is evidence that a number of outbreaking insect species have increased their ranges and the severity of forest damage that they've caused in recent times but these may be compensated by reductions in damage by other insect pests. Thus finally (4), I ask whether climate and forestry have amplified outbreaks of major forest insect pests across North America?