
We wanted rain, and we’ve got rain. Along with flooding in some parts of California, though, the rain has brought other unexpected consequences. Our trees are falling over.
As reported here, the drought has killed more than a hundred million trees throughout the state and has weakened many more; officials estimate that even once conditions return to normal the die-off will continue for a year or two. With the recent storms—rain, high winds, and soggy, softened ground—many of the dead and dying trees are falling. Two people have been killed and several others injured. A famous “tunnel tree”—a giant sequoia with a hole large enough for cars to drive through—fell in a state park.
Ironically, the abundant rain is causing the deaths of trees that might not otherwise have died, or at least not yet. Healthier trees that still have a relatively large leaf canopy can be more vulnerable once the ground softens, because the canopy acts as a sort of sail, catching the wind and making the trees more likely to topple. Those that have lost leaves because of the drought are actually less susceptible to the wind. And, as a forestry professor points out in this article, the return of the rain can actually cause weakened trees to die rather than rebound, as they try to absorb too much water too quickly—a situation he likens to a starving person suddenly gorging on too much food.
Officials are working to cut down trees that might pose a danger—those near roads, homes, and other public spaces. They’re also concerned, still, that the dead trees will provide fuel for wildfires. In the meantime, one forestry official warns, “Pay attention to your surroundings and watch those trees.”
Janice Kaspersen
Janice Kaspersen is the former editor of Erosion Control and Stormwater magazines.