Bark beetle outbreaks in coniferous forests : a review of climate change effects

Abstract

Extreme weather episodes related to anthropogenic climate change have enhanced the frequency and magnitude of bark beetle disturbance, causing worldwide mortality of forests in the last decades. Changes in temperature and precipitation regimes are altering the relationships between host tree populations and associated bark beetle species, as these insect-host systems are highly sensitive to climate extremes. However, it is not fully understood how climate interacts with the different components of bark beetle-host systems, and thus, the existing knowledge is still insufficient to face the challenges of understanding the system response to changing environmental conditions. Here, we review the most important findings of the influence of climatic factors on the dynamics of bark beetle and host tree populations at different spatiotemporal scales. Future research should integrate how the effects of climate on individual tree responses to beetle attack scale up to outbreak patterns at regional scale. Recent advances in plant physiology, disturbance ecology, ecological niche modelling, and remote sensing can further our understanding of the risks of bark beetle disturbance in forest ecosystems under changing climate.