Recent Advances in Remote Sensing for Early Detection, Risk Prediction, and Post-disturbance Assessment of Bark Beetle Attacks in Temperate and Boreal Forests

Purpose of Review The occurrence of biotic forest disturbances caused by pests such as bark beetles has increased significantly in recent decades. The severity of the disturbances is exacerbated by climate change-driven environmental conditions that favour pests, leading to widespread tree mortality worldwide. Existing remote sensing approaches have provided valuable insights into understanding the spatial and temporal patterns of bark beetle-induced tree mortality. We review and discuss current challenges and research gaps in the field to provide pathways for future research on bark beetle infestation detection, spatial prediction of infestation risk and future spread, and post-disturbance management. Recent Findings We identified several under-addressed topics, including (i) knowledge gaps in tree eco-physiological processes and lack of domain integration for remote sensing-based early stress detection; (ii) lack of remote sensing-assisted large-scale assessments of susceptibility to disturbance, and (iii) under-exploitation of remote sensing-based methods for post-disturbance assessment and for decision support for forest management of disturbed areas. Summary Aside from direct detection of signs of beetle attacks, earth observation has been used for mapping forests’ susceptibility to bark beetle disturbance and for the assessment of post-disturbance impacts. However, studies focusing on the latter two topics are still comparably rare and these topics may hold further potential if sensor and scale synergies are better exploited and ecological process understanding is integrated. Near-real-time large-scale monitoring, infestation prediction scenarios, and pre-/post-disturbance risk assessments derived from remotely sensed observations have the potential to inform and optimise decision-making of current and future forest management.