OAKLAND (KPIX 5) — There’s new color in the East Bay Hills but they are not fall colors. The changing leaves may be the result of a mysterious and deadly tree fungus attacking acacia trees all across the Bay Area.

Tens of thousands of acacia trees are dead and dying across this ridge above Oakland. Scientists are collecting samples of wood to study in labs, trying to determine what exactly is killing the trees. They may have a clue.

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“It’s a fairly new fungal pathogen called the pistachio canker, originated in Italy,” said Natalie Vandoorn, an urban ecologist researcher for the U.S. Forest Service.

Scientists caution they’ve also identified several other fungi, so the preliminary data is just that, preliminary.

People in the neighborhood started noticing it last summer. Marilyn Rhodes is 93. She has lived here a long time and has specific concerns.

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“I noticed because I am very fire conscious because these hills burned just a year after I moved here in 1960,” said Rhodes. “The whole hill burned and fortunately not one of our houses burned but it very frightening to think it could happen again.”

Cutting down and chipping the trees could spread the fungus spores and make matters worse. There appears to be no easy or cheap solution says Mark Rauzon.

“We’re at just the tip of the iceberg on this problem, this ecological problem and it’s much bigger than Oakland,” said Rauzon.

Scientists agree that more study is needed to formulate a path to deal with this new fungus.

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“It’s widespread and we know a little bit but, really not a lot yet,” said Vandoorn.