The Threat on Millions of American Trees from Bugs in California

California has 102 million dead trees — and no easy answers for what to do with them
Based on aerial surveys, the U.S. Forest Service concluded that more than 102 million trees have died across the state’s forests since 2010. More than half — 62 million — died this year alone. There are 4.1 billion live trees in California forests, according to U.S. Forest Service data. So the dead trees represent about 2.5% of that population.

What caused the die-off?

Scientists say five years of drought are to blame for much of the destruction. The lack of rain has put California’s trees under considerable stress, making them more susceptible to the organisms, such as beetles, that can kill them.  Unusually high temperatures have added to the trees’ demand for water, exacerbating an already grim situation.

http://www.latimes.com/local/lanow/la-me-ln-dead-trees-explained-20161128-story.html

27 million Southern California trees at risk of dying

Tree-killing bug invades Southern California, with no answer in sight