Climate-Change-Driven Droughts and Tree Mortality: Assessing the Potential of UAV-Derived Early Warning Metrics.

Ewane, Ewane Basil; Mohan, Midhun; Bajaj, Shaurya; Galgamuwa, G. A. Pabodha; Watt, Michael S.; Arachchige, Pavithra Pitumpe; Hudak, Andrew T.; Richardson, Gabriella; Ajithkumar, Nivedhitha; Srinivasan, Shruthi; Corte, Ana Paula Dalla; Johnson, Daniel J.; Broadbent, Eben North; de-Miguel, Sergio; Bruscolini, Margherita; Young, Derek J. N.; Shafai, Shahid; Abdullah, Meshal M.; Jaafar, Wan Shafrina Wan Mohd; Doaemo, Willie

Protecting and enhancing forest carbon sinks is considered a natural solution for mitigating climate change. However, the increasing frequency, intensity, and duration of droughts due to climate change can threaten the stability and growth of existing forest carbon sinks. Extreme droughts weaken plant hydraulic systems, can lead to tree mortality events, and may reduce forest diversity, making forests more vulnerable to subsequent forest disturbances, such as forest fires or pest infestations. Although early warning metrics (EWMs) derived using satellite remote sensing data are now being tested for predicting post-drought plant physiological stress and mortality, applications of unmanned aerial vehicles (UAVs) are yet to be explored extensively. Herein, we provide twenty-four prospective approaches classified into five categories: (i) physiological complexities, (ii) site-specific and confounding (abiotic) factors, (iii) interactions with biotic agents, (iv) forest carbon monitoring and optimization, and (v) technological and infrastructural developments, for adoption, future operationalization, and upscaling of UAV-based frameworks for EWM applications. These UAV considerations are paramount as they hold the potential to bridge the gap between field inventory and satellite remote sensing for assessing forest characteristics and their responses to drought conditions, identifying and prioritizing conservation needs of vulnerable and/or high-carbon-efficient tree species for efficient allocation of resources, and optimizing forest carbon management with climate change adaptation and mitigation practices in a timely and cost-effective manner.

DROUGHT management; DROUGHTS; TREE mortality; CLIMATE change mitigation; CARBON cycle; CLIMATE change; FOREST monitoring

Remote Sensing, 2023, Vol 15, Issue 10, p2627

2072-4292

Academic Journal

10.3390/rs15102627