There are three trillion trees in the world…but 15 billion trees are felled every year, and only five billion are planted.

Trees grow from the top, which is why nest boxes and tree-houses always remain the same height.

Counting the rings inside a tree to assess its age is a process known as dendrochronology.

The world’s oldest tree is a bristlecone pine in Nevada named Prometheus thought to be more than 4,900 years old.

Unlike mammals and other creatures, trees never die of old age and all trees are capable of growing forever so long as they remain supplied with light and water, free from disease, and not harmed by floods, fires, or pests.

The world’s tallest known living tree is a California coastal redwood named Hyperion. It stands just over 380 feet tall.

Because trees absorb carbon dioxide and produce oxygen, they can offset global carbon emissions. However, it would take a forest of 450 individual trees to offset the average carbon output of a single human being.

In 1971, NASA took some tree seeds to the Moon on Apollo 14 and returned them to Earth to see if germinating in space would affect their growth. The trees they planted are now the property of the US Forestry Service.