At Sacramento City College, a downed cedar, huge and fragrant, blocked the entrance to campus. In a manicured neighborhood near the American River, Marco Leyva, a local landscaper, scrambled to retrieve fallen tree limbs, his truck piled high with redwood, oak and liquid amber. Some, he said, appeared to have fallen partway in the New Year’s Eve storm, “and then the wind this time just knocked them down.”
The toll on trees is more than ornamental and nostalgic. At critical juncture in adapting to climate change, scientists say that trees are a physical barometer and manifestation of failure and success.
In California cities, the urban canopy is a critical piece of environmental infrastructure, cooling sidewalks, cleansing air, creating wildlife habitat and giving people of all socioeconomic backgrounds respite from intensifying heat waves. In more remote places, where disease and drought have already turned vast tracts of wilderness into kindling, the fallen trees, unless they are quickly cleared, invite wildfire and pests.
In a news conference, Ms. Nemeth, the state water resources director, blamed the horticultural devastation on the drought as well as the violent weather. “We’re moving from extreme drought to extreme flood,” she said. “What that means is, a lot of our trees are stressed.”
At the same time, weather systems shifted by climate change have amplified wind and precipitation, said Jeffrey Mount, a senior fellow at the Public Policy Institute of California’s Water Policy Center. Last weekend’s storm was very wet — essentially, an atmospheric fire hose hanging over California — but this week’s “bomb cyclone” storm brought much more wind, Dr. Mount said.