Silvicultural control of spruce budworm

每年，森林昆虫和疾病的破坏导致加拿大森林纤维生产力下降30%（Alfrel和Volney 2002）。 云杉芽虫在最近一次爆发期间（1968-1987年），在魁北克省造成了5亿立方米的损失（死亡率+生长减少）（Coulombe等人，2004年）。部分采伐针叶林最近已在魁北克商业北方森林推广，以提高森林实践的社会可接受性，产生高质量的日志，随着时间的推移，在可持续产量的背景下修改树木采伐时间表，并管理野生动物栖息地。 我们假设，部分切割也可以用来增加宿主树云杉芽虫的抗性，因此可以减少对加拿大经济的主要森林害虫的经济影响，但立场部分切割的影响随着时间的推移而变化，并根据水平的收获密度，网站质量和宿主树种。 目前研究建议采用的科学方法涉及确定昆虫的反应（幼虫生长、发育、食物利用和行为、成虫行为）、寄主树反应（叶子化学、叶子产生、被昆虫去除的叶子、生长、活力）和非生物条件的改变（土壤和空气温度和湿度）根据测试的各种变量（部分切割密度、立地质量、宿主物种）。 我们的科学方法不仅允许记录部分切割对宿主树抗性的影响，而且还允许我们记录昆虫和宿主树水平上涉及的潜在生物和生理过程。这将有助于更好地了解如何针叶林可以通过造林的做法，以减少云杉芽虫对加拿大经济的经济影响进行操纵。此外，这项研究将提供一个更好的了解树木-昆虫系统的相互作用，因此可能会有重大影响的作用，植物的种群动态的云杉夜蛾。

Each year, forest insects and diseases damages cause 30% reduction in Canadian forest fiber productivity (Caroll and Volney 2002).  During its last outbreak (1968-1987), spruce budworm caused 500 million m3 losses (mortality + growth reduction) in the province of Quebec (Coulombe et al. 2004). Partial cutting in coniferous stands has been recently promoted in Quebec commercial boreal forest to increase the social acceptability of forest practices, to generate high quality logs, to modified schedules of tree harvesting over time in the context of sustainable yield, and to manage wildlife habitat.  We hypothesize that partial cutting could also be used to increase host tree resistance to spruce budworm and hence could reduce the economical impact of that major forest pest on the Canadian economy, but that the impact of stand partial cutting varies over time and according to the level of harvesting densities, site quality and host tree species.  The scientific approach adopted in the current research proposal involves the determination of insect responses (larval growth, development, food utilization and behavior, adult behavior), host tree responses (foliage chemistry, foliage production, foliage removed by the insect, growth, vigor) and abiotic conditions modifications (soil and air temperature and humidity) according to the various variables tested (partial cutting density, site quality, host species).  Our scientific approach will not only permit to document the impact of partial cutting on host tree resistance across a range of several important variables, but also will allow us to document the underlying biological and physiological processes involved at the insect and host tree level. This will contribute to a better understanding of how coniferous stand can be manipulated through silvicultural practices to reduce the economical impact of spruce budworm on the Canadian economy. Also, this study will provide a better understanding of the tree-insect system of interactions and consequently could have major impact on the role of the plant in the population dynamics of spruce budworm.