Can spruce forest stands be adapted to climate-driven natural disturbances? The consequential effects of two key disturbance agents and their management in spruce dominated stands under climate change – A review

Abstract

The purpose of the thesis is to support the initial stage of the Climate Smart Forestry Norway (CSFN) undertaken by a consortium between NMBU, NIBIO, LUKE (Finland), and Wageningen University & Research, which is a five-year project aimed to assess how Norway’s forests are best managed in order to adapt to climate change. As part of the CSFN project a framework for quantifying probability and effects of natural disturbance linked to forest structure and climate change will be developed. Before quantifying probabilities of the main natural disturbances, a literature review on these main disturbance agents is set to begin in 2020, which is going to be supported by this Master project. Extensive damages to Norwegian spruce in Europe after massive outbreaks preceded by windstorms have moved scientists and foresters from trying to control the Eurasian spruce bark beetle to attempt to decipher the reasons behind epidemic populations. Previous literature has uncovered the physiological thresholds behind massive spruce bark beetle outbreaks. But changes in temperature averages, precipitation and human land use throughout Europe have called for different management strategies in the light of the strong coupling of climatic factors and spruce monoculture implementation to spruce bark beetle propagation, by means of direct and indirect effects. The strong interaction of windthrow, acute drought and spruce bark beetle outbreaks resulting in epidemic populations has been synthesized in this review and some of the proposed beetle control tools and landscape-forest stand management strategies from recent frameworks and reviews, such as Climate Smart Forestry, are introduced as a potential management solution to dampen the adverse consequences of climate-driven insect disturbances in boreal forests.