World’s largest tree passes health check

SEQUOIA NATIONAL PARK, California — High in the evergreen canopy of General Sherman, the world's largest tree, researchers searched for evidence of an emerging threat to giant sequoias: bark beetles. The climbers descended the towering 2,200-year-old tree with good news on Tuesday. "The General Sherman tree is doing fine right now," said Anthony Ambrose, executive director of the Ancient Forest Society, who led the expedition. "It seems to be a very healthy tree that's able to fend off any beetle...