Interaction between forest tent caterpillar and forest composition: Role of predation in outbreak dynamics and effects on litter, soils and tree regeneration

森林帐篷毛毛虫与森林组成之间的相互作用：捕食在爆发动态中的作用以及对凋落物、土壤和树木再生的影响

• 批准号: 522722-2017
• 负责人: Lafleur, Benoit
• 金额: $ 0.95万
• 依托单位: Université du Québec en Abitibi-Témiscamingue
• 依托单位国家: 加拿大
• 项目类别: Collaborative Research and Development Grants
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=697680
• 关键词: Interaction; between; forest; tent; caterpillar

The forest tent caterpillar (FTC) is a significant defoliator of hardwood stands throughout Canada. Currently, in Quebec there are two foci in which outbreaks appear to cycle independently: one in the south on sugar maple and one in the north on trembling aspen. In these forest types, severe outbreaks occur at approximately 10-year intervals and are responsible for decreases in forest productivity. Historically, outbreaking populations collapsed after one or two years of defoliation, but longer and more severe outbreaks have been observed in the recent years. For this reason, in the context of the projected climate change it is thought that FTC outbreaks may become more severe and result in more significant losses of forest productivity. FTC outbreaks are characterized by extreme population fluctuations and highly variable mortality rates. Recent studies suggest that predation plays an important role in population control. However, our understanding of predation rates and the relative importance of different predators on FTC remain highly hypothetical. Furthermore, during outbreaks FTC could increase the amount of organic matter to the soil and increase resources available to detritivores. These modification could have important effects on the structure of soil invertebrate communities and influence decomposition of organic matter, nutrient availability, and tree seedlings survival and growth. On the long term, these effects could exert important controls on forest stand composition. The objectives of this project are to better understand 1) the role of predators in keeping down and ending FTC outbreaks and 2) the effects of FTC outbreaks on soil arthropod communities, soil processes, and tree regeneration. This project will provide a better understanding of forest ecosystem functioning and contribute to the development of innovative silvicultural approaches. For instance, our project will allow for the identification of stand types most likely to be affected by future FTC outbreaks. This study will also contribute to better anticipate future FTC outbreaks and conduct pre-emptive harvesting of vulnerable tree species and stand types. These interventions will help maintain the timber supply for the Canadian forest industry.

森林帐篷毛毛虫（FTC）是整个加拿大硬木摊位的重要截肢者。目前，在魁北克，有两个焦点，其中爆发似乎是独立循环的：一个在南方的糖枫树，一个在北部的颤抖的阿斯彭。在这些森林类型中，严重的暴发大约在10年的间隔内发生，并导致森林生产力降低。从历史上看，一两年的脱叶后，爆发的人群崩溃了，但近年来已经观察到了更长和更严重的爆发。因此，在预计气候变化的背景下，人们认为FTC暴发可能会变得更加严重，并导致森林生产力造成更大的损失。 FTC暴发的特征是人口极端波动和高度可变的死亡率。最近的研究表明，捕食在人群控制中起重要作用。但是，我们对捕食率和不同捕食者对FTC的相对重要性的理解仍然是高度假设的。此外，在暴发期间，FTC可能会增加土壤的有机物数量，并增加可用于衰落的资源。这些修饰可能对土壤无脊椎动物群落的结构产生重要影响，并影响有机物，养分可用性以及树幼苗的生存和生长的分解。从长远来看，这些影响可能会对森林支架组成产生重要的控制。该项目的目标是更好地理解1）捕食者在减少FTC暴发和结束FTC暴发中的作用，以及2）FTC暴发对土壤节肢动物群落，土壤过程和树木再生的影响。该项目将更好地了解森林生态系统的功能，并为创新的造林方法的发展做出贡献。例如，我们的项目将允许识别最有可能受到FTC爆发的影响。这项研究还将有助于更好地预期未来的FTC暴发，并对脆弱的树种和立场类型进行先发制人的收获。这些干预措施将有助于维持加拿大森林行业的木材供应。