Tree

A tree is a tall plant with a single woody stem called a trunk. Trees grow taller than most other plants and can live for a very long time. They are found on every continent except Antarctica. Scientists think there are about 3 trillion trees on Earth, which works out to nearly 400 trees for every person.

Every tree has the same basic parts. The roots reach down into the soil to soak up water and minerals. The trunk holds the tree up and carries water and food between the roots and the leaves. Branches spread out from the trunk and hold up the leaves. The leaves use sunlight to make food through a process called photosynthesis. A layer of bark wraps around the trunk like skin, protecting the soft wood inside.

Trees come in two main groups. Deciduous trees, like oaks and maples, drop their leaves every fall and grow new ones in spring. Evergreen trees, like pines and firs, keep their needle-shaped leaves all year. The needles fall off too, but only a few at a time, so the tree always looks green.

Trees grow taller at their tips, but their trunks grow wider in rings. Each year, a tree adds one new ring of wood under its bark. By counting the rings on a cut stump, scientists can tell exactly how old the tree was. Wide rings mean a good year with plenty of rain. Thin rings mean a hard year, maybe a drought or a cold summer.

Some trees reach amazing sizes. The tallest tree alive today is a coast redwood in California named Hyperion. It stands about 380 feet tall, taller than the Statue of Liberty. The widest known tree, a giant sequoia called General Sherman, weighs more than 1,200 tons. That is heavier than 200 elephants stacked together.

Trees do enormous work for the planet. They pull carbon dioxide out of the air and release oxygen, which animals and people need to breathe. Their roots hold soil in place and keep it from washing away in the rain. Their shade cools cities. Their fruits, nuts, and seeds feed countless animals, including humans. Forests are home to more than half of all the land animals and plants on Earth.

Trees also live in human stories. Apple trees, olive trees, and cherry blossoms appear in legends, religions, and national symbols around the world. The tree is one of the oldest signs of life, growth, and connection in human imagination.