California’s extraordinarily wet winter didn’t just end the drought. It’s likely to mean a turnaround for the state’s dying forests.

After five years of dry weather unleashed unparalleled havoc on trees from Yosemite to the Central Coast — leaving vast stands of pine too parched to fight pests and reducing entire mountainsides to browning wastelands — a forecast by the U.S. Forest Service suggests the die-off will slow this year.

The projection, made public earlier this year, is short on specifics. But it mirrors the opinion of many forestry experts who say fewer trees will perish as rainy weather helps California’s woodlands regain their natural defenses against the ravenous bark beetle.

“When we’ve had huge precipitation years, the mortality declines in the same or next year,” said Sheri Smith, a regional entomologist for the Forest Service. “It’s not like there isn’t going to be any new mortality, but we’re going to see a tremendous drop.”

With improvement imminent, the question scientists are asking now is what will happen to the lifeless swaths of forest that span some 7.7 million acres — an area twice the size of Connecticut.

An estimated 102 million trees have died over the past six years, mostly in the southern and central Sierra but to a degree in every part of the state. It’s a level of carnage many say is unprecedented and will forever change the California landscape.

The die-off, which prompted Gov. Jerry Brown to declare a state of emergency two years ago, began when trees, mainly pine but also oak, cedar and fir, became weakened by drought and easy prey for the beetle. The decline was hastened by already-crowded forests — a product of antiwildfire policies — which increased competition among trees for soil, sunlight and water.

Smith said most trees will fare better now. Not only are there fewer trees to slug it out because of the die-off, but they have the moisture they need to create pitch, or resin, which is their primary weapon against infestation.

“The beetle gets caught in the pitch before it gets into the tree,” she explained. “It’s the same as if you or I were trying to get into our house door. The lock on the door is the pitch on the tree.”

Back to Gallery California’s huge tree die-off expected to slow after... 3 1 of 3 Photo: Michael Macor / Michael Macor / The Chronicle 2 of 3 Photo: Michael Macor / Michael Macor / The Chronicle 3 of 3 Photo: Michael Macor / Michael Macor / The Chronicle





Before this year, many trees stood eerily void of pitch, or so-called pitch tubes, which represent the discharge of resin. Instead, they offered only boring dust, a sign of a battle lost to the native insects.

This winter’s rain and snow won’t so much affect the beetle population, Smith said, as it will affect their success entering the tree. The insect and its larvae seek to feed on the inner tissue, and while attacks under way before the wet weather are likely to continue, new assaults are apt to be repelled.

Michelle Miller, part owner of Miller’s Landing Resort in Bass Lake (Madera County), has been at ground zero of the tree epidemic, and she’s hopeful the worst is over.

“We anticipate that it’s going to be a great year,” she said, while working on the family property, which contains cabins for rent, a general store and an ice cream fountain.

Many of the towering ponderosa pines on her parcel are alive because her family kept them watered — only about 30 dead trees had to be felled, she said. But nearby, as many as 80 percent of the trees have died, an ordeal that Miller and many locals are trying to put behind them.

“The lake is full now, and with all the pine needles dead and fallen, you can see green trees again,” she said.

The dead trees continue to pose a hazard, however, both for fire danger and for people on the ground.

The governor’s emergency declaration for the forests has ushered in tens of millions of dollars to address safety issues. So far, roughly 500,000 trees have been removed and miles of fuel breaks have been cut in a joint effort by the Forest Service, the California Department of Forestry and Fire Protection, the California Department of Transportation and private utilities. Pacific Gas and Electric Co. alone removed 236,000 dead or dying trees last year.

“Knock on wood, we haven’t had any accidents,” Miller said.

The Forest Service forecast, which was done before the big rains in January and February, predicts that fewer trees will die this year than last — when an estimated 62 million trees withered. The projection is based on historic conditions in California forests.

Looking at mortality and beetle infestations of the past, including a huge tree die-off in Southern California early last decade, officials have noted quick rebounds when dry periods end.

“We have seen similar stuff before, at different places,” said lead author Haiganoush Preisler, a statistical scientist for the Forest Service.

For some parts of the state, the drought wrapped up with a wet winter last year, while this year’s weather brought an end just about everywhere else. With some parts of California on the verge of record rainfall, Brown declared an official end to the drought Friday.

Although tree mortality is likely to decline in coming months, Preisler cautioned that some spots might see more, but just briefly. The northern coast, where casualties have been light, is one such place. Widespread problems are not anticipated.

Scientists are already beginning to speculate how California’s forests will emerge from the ruin.

“In some of those hard-hit areas in the southern Sierra, they’ve lost nearly all the trees,” said Tom Smith, forest pest management specialist for Cal Fire. “The question is not so much when is the pine going to return, but what is going to return.”

Lower-elevation forests dominated by ponderosa pine may see brush and grassland take hold where tree canopy no longer blocks sunlight. Such prairie-type habitats are apt to thrive in the future, when warmer, drier periods are more likely, climate models show.

Shifts in vegetation would reverberate through the ecosystem, resetting the range of many plants and animals.

Some researchers say the wholesale change is not necessarily a bad thing.

Chad Hanson, research ecologist with the nonprofit John Muir Project, said tree die-off is part of the natural progression of the forest, often absent under current fire-suppression policies, and benefits a whole host of life.

“You get this great rejuvenation of flowering plants, and bees, wasps, dragonflies and insects, which brings birds,” he said. “And the shrubs provide food for small mammals. ... then mule deer come in to eat, and bears get berries.”

While many fear that the largely dead forests present increased risk of fire, Hanson is among many who say the standing timber is no more dangerous than living trees. In fact, they say, it can be less threatening because there are fewer needles and less foliage to burn.

“From my perspective, you want a lot of live trees and you want a lot of dead trees in the forest,” Hanson said. “It’s just good for biodiversity.”

Kurtis Alexander is a San Francisco Chronicle staff writer. Email: kalexander@sfchronicle.com Twitter: @kurtisalexander