Three years ago, forest scientists on the U.S. West Coast launched an effort to gather nearly 1 million seeds of the Oregon ash. The ecologically valuable tree, found from southern California to British Columbia in Canada, often grows along streams and in wetlands, anchoring rich ecosystems.In part, the collecting effort represented disaster insurance: The emerald ash borer, an invasive, iridescent green beetle that has wiped out ash trees throughout much of the eastern and midwestern United States, was spreading westward, and the saved seeds might one day help restore the species if the pest ever arrived.
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