The Swiss needle cast epidemic in Douglas-fir forests of the coastal Pacific Northwest is continuing to intensify, appears to be unprecedented over at least the past 100 years, and is probably linked to the extensive planting of Douglas-fir along the coast and a warmer climate, new research concludes.

Two U.S. researchers advise consumers to think twice about spending money on a commercial flame retardant for a Christmas tree. Drs.

This Christmas season, think twice about spending money on a commercial flame retardant for your Christmas tree.

Five tall trees in a Seattle park have been deliberately killed with an injection of an herbicide, and two more are turning brown, officials said.

By KATHIE DURBIN By kathie durbin Ian Sinks of the Columbia Land Trust surveys a fallen oak near a fir-thinning operation on the rim of the Columbia River Gorge. The Oregon white oak, a "priority species" in Washington, can live up to 500 years.