Kunik et al. (2026) Characterizing effects of tree mortality from wildfire and bark beetles using satellite observations of solar-induced chlorophyll fluorescence

Identification

• Journal: Remote Sensing of Environment
• Year: 2026
• Date: 2026-06-26
• Authors: Lewis Kunik, D. R. Bowling, Brett Raczka, Jeffrey A. Hicke, Christian Frankenberg, Rui Cheng, Michèle R. Slaton, John C. Lin
• DOI: 10.1016/j.rse.2026.115550

Research Groups

• Department of Atmospheric Sciences, University of Utah
• School of Biological Sciences, University of Utah
• Computational and Information Systems Laboratory, National Center for Atmospheric Research
• Department of Earth and Spatial Sciences, University of Idaho
• Division of Geological and Planetary Sciences, California Institute of Technology
• Jet Propulsion Laboratory, California Institute of Technology
• Kravis Department of Integrated Sciences, Claremont McKenna College
• Inyo National Forest, U.S.D.A. Forest Service

Short Summary

This study investigates the sensitivity of satellite solar-induced chlorophyll fluorescence (SIF) to tree mortality from wildfires and bark beetle outbreaks in western US forests using TROPOMI SIF observations and gridded datasets of tree mortality.

Objective

• Investigate the relationship between SIF and tree mortality from wildfires and bark beetles.
• Determine if SIF can be used as a tool for early warning of drought and mortality.

Study Configuration

• Spatial Scale: 0.05° (~5 km) spatial resolution over the western US.
• Temporal Scale: Daily-integrated mean SIF (SIFdc) aggregated to 16-day resolution from 2018 through 2023.

Methodology and Data

• Models used: TROPOMI L2B far-red SIF observations at 740 nm.
• Data sources: MODIS satellite instruments for vegetation products, climate reanalysis products, and USDA Forest Service Aerial Detection Surveys (ADS) for tree mortality data.

Main Results

• SIF declined sharply in response to wildfire, with differences from control increasing with burn severity, and SIF declining to as low as 20% of pre-fire levels.
• Moderate-to-severe bark beetle-induced mortality showed declines in growing season SIF to 60-70% of pre-drought levels over multiple years.
• Bark beetle-related declines in SIF were 10-20% greater in magnitude than those of control areas, exhibiting statistical significance from the control two to three years prior to visible detection from aircraft surveys.

Contributions

• This study provides new insights into the relationship between SIF and tree mortality from wildfires and bark beetles.
• The results suggest that SIF can be used as a tool for early warning of drought and mortality in western US forests.

Funding

• National Science Foundation (NSF)
• NASA's Terrestrial Hydrology Program
• USDA Forest Service

Citation

@article{Kunik2026Characterizing,
  author = {Kunik, Lewis and Bowling, D. R. and Raczka, Brett and Hicke, Jeffrey A. and Frankenberg, Christian and Cheng, Rui and Slaton, Michèle R. and Lin, John C.},
  title = {Characterizing effects of tree mortality from wildfire and bark beetles using satellite observations of solar-induced chlorophyll fluorescence},
  journal = {Remote Sensing of Environment},
  year = {2026},
  doi = {10.1016/j.rse.2026.115550},
  url = {https://doi.org/10.1016/j.rse.2026.115550}
}