More than 3 trillion trees now grow on Earth, seven times more than scientists previously thought. But it's also trillions fewer than there used to be, a new study concludes. A United ...

Look up at the night sky and you might feel dwarfed by the glimmer of countless stars. Now shift that view downward, press your mind to the ground and the green world under your feet—and you’ll find ...

A year after a wildfire, the U.S. Forest Service assesses the damage to figure out how many trees need to be planted to restore the forest. But research shows that much more time is needed to ...