Beavers are really important.

After the huge wildfires in Oregon in 2022, a biologist went out to survey the damage. Not only were the forests blackened, thriving trout populations in the streams were gone, choked to death by ash. “I was in total shock. It just looked like devastation.”

Then he stumbled upon something even more surprising: roughly five acres of pristine greenery in an otherwise burned-out area! At the center were eight active beaver dams.

But this was more than a refuge from the fire. While fish had disappeared upstream of these dams, the downstream water was crystal clear — and trout were thriving as though the fire had never happened! The beaver dams were acting as a water treatment plant.

[Paraphrased from this article: https://www.scientificamerican.com/article/beaver-dams-help-wildfire-ravaged-ecosystems-recover-long-after-flames-subside/]