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 ...

Add Yahoo as a preferred source to see more of our stories on Google. 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 ...

Here's a look at Christmas trees by the numbers: 3 Rank of Pennsylvania in the nation for the number of Christmas tree farms 4 Rank of Pennsylvania in the nation for acreage of Christmas trees in ...