Weakened by Drought, Trees are Falling in Drenched California

Drenching winter rains combined with the punishing effects of six years of drought are causing trees to topple across California, in some cases with deadly results. At least two people have been killed in the past month.

Seemingly sturdy oaks, palm trees in Southern California and giant sequoias farther north have been collapsing. Experts say that in some instances, the dry spell had weakened or killed the roots or trunks, and the soggy soil and wind caused the trees to tip over.

One woman who struck and killed by a tree while walking on a Northern California golf course Saturday. A woman posing for photographs as part of a wedding party was killed and five others were injured by a falling eucalyptus tree in Southern California last month.

A towering conifer in front of Joe Lauri’s home in Fresno came crashing down during the weekend storm, giving in to shallow roots and the weight of rain-soaked pine needles. Lauri said he was relieved the damage wasn’t worse.

“What can you do?” he said. “It could have landed on the house.”

Another wet, blustery storm headed for California on Tuesday night threatened to knock down many more trees in the Sierra Nevada and neighborhoods throughout the state.

“Pay attention to your surroundings and watch those trees,” said Battalion Chief Scott McLean of the California Department of Forestry and Fire Protection. “It is a hazard you need to be aware of.”

Days of back-to-back storms have brought the heaviest rain in a decade to parts of Northern California and Nevada, flooding homes, roads and vineyards. Some areas got more than a foot in the 72-hour period that ended early Monday, and then got rained on again on Tuesday.

In a state park near the town of Arnold, a beloved giant sequoia that became a drive-thru tourist attraction decades ago when a tunnel was cut through its trunk crashed to the ground during the weekend storm. The ancient tree was sickly and barely alive before the storm.

Authorities had no immediate estimate of how many trees have toppled.

The epic drought gripping California has killed more than 102 million trees in the Sierra Nevada, in many cases by weakening them so much that they became vulnerable to attack by bark beetles.

A huge effort is underway in the Sierra Nevada to cut down dead trees near roads and homes before they fall. There are also fears that the deadwood could fuel catastrophic wildfires.

William Libby, a retired professor of forestry and genetics at the University of California, Berkeley, said that after a heavy rain, trees weakened by drought have been known to die suddenly instead of rebounding. He likened it to giving a starving person too much food too fast.

“When you’re really weakened, trying to come back in a hurry, it is probably not a good idea,” he said.

Lisa Smith, an arborist and president of the Western Chapter of the International Society of Arboriculture, downplayed the role of drought in knocking over trees.

She said that even healthy trees can give way if the ground is soft and their leaves catch the wind, pushing over the tree and leaving their leafless neighbors standing.

“Many trees that are drought-stressed and have limited foliage, ironically, may be sparse in their canopy and thus less prone to wind sail,” she said.