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| California's 2017 Thomas Fire (shown) was included in a new analysis of more than 1,500 wildland fires teasing out how drought and fire combine to affect western U.S. lands. |
A recent NASA study, utilizing satellite data, delves into the impact of drought on the post-fire recovery of western ecosystems, offering insights vital for conservation efforts.
In the Western U.S., the escalation in the frequency and severity of wildfires, exacerbated by climate change and past fire suppression efforts, has become a significant concern. However, quantifying the combined effects of fire and drought on ecosystems has presented challenges.
Researchers analyzed over 1,500 wildfires spanning from 2014 to 2020, along with drought data dating back to 1984. Their findings, published in the February 2024 issue of Nature Ecology & Environment, reveal that droughts hinder the recovery of grasslands and shrublands, such as those in Nevada and Utah, post-fire, even with less severe blazes. Conversely, forests, if not severely burned, exhibit better recovery due to some roots accessing deeper groundwater.
Shahryar Ahmed, the lead author and a researcher at NASA's Goddard Space Flight Center, emphasizes the prolonged recovery in grassland ecosystems following low-severity fires, particularly when preceded by drought.
The study underscores the potential consequences of insufficient recovery time, including permanent changes in plant composition, heightened risk of erosion and landslides, and altered water runoff patterns. Everett Hinkley from the U.S. Forest Service underscores the importance of post-fire remediation efforts tailored to specific ecosystems.
To monitor ecosystem recovery, researchers analyzed changes in evapotranspiration (ET) before and after fires. Leveraging OpenET, a tool utilizing Landsat satellite data, the team tracked ET changes across different ecosystems.
Erin Urquhart from NASA Headquarters stresses the necessity for collaborative efforts informed by such research to adapt to climate-induced changes and ensure sustainable resource management.
The study also highlights the enduring impact of high-severity fires occurring alongside droughts, with severe fires significantly reducing post-fire evapotranspiration and altering water dynamics.
In a subset of fires from 2016 to 2018, researchers calculated substantial water diversion as runoff or recharge, potentially impacting ecosystem recovery and water availability for agriculture.
Understanding these shifts is vital for effective water resource management in a warming climate, emphasizing the urgency of developing strategies for water security.