OK, so what exactly is a forest? According to Britannica, "a forest is a complex ecological system in which trees are the dominant life-form." There's more to forests than trees, though! Forests can be home to everything from small worms in the soil to lumbering bears who feast on wild berries to birds that fill the air with their bright songs. The more animals the better: it is a good sign when a forest has healthy biodiversity (the variety of all living things and their interactions).

While all forests are dominated by trees, the Amazon Rainforest and the Russian Taiga look very different. As a rule of thumb, there are three general types of forests in the world: tropical forests, temperate forests and boreal forests. Temperate rainforests grow across eastern North America and the continent of Eurasia. Tropical forests occur near the equator, in places like Southeast Asia, sub-Saharan Africa, and Central America. Boreal forests form a massive "belt" around the world's northern hemisphere, covering much of Siberia, Scandinavia, and northern North America.

Everything that lives in a forest is part of its ecosystem, and the amount of biodiversity found in these ecosystems is truly astounding. In fact, more than 80% of the plants, animals and insects living on land can be found in the world's forests! This includes approximately 60,000 tree species, 80% of amphibian species, 75% of bird species, and 68% of mammal species. The world's biodiversity needs our help protecting its home.

10,000 years ago, long before human civilizations began cutting down forests to build cities and create farmland, forests covered about 57% of the habitable land on Earth. Despite how important they are, trees continue to be chopped down at an alarming rate, causing many to worry about the state of the world's forests now and in the future. 

Forests get cleared for many reasons, but some of the biggest ones relate to feeding and housing the world's growing population. Trees are cut so farmers can grow more food and raise livestock like cows, pigs, and sheep. They're also logged to provide lumber for building houses, and for making familiar items like the table you eat your dinner at and the paper and pencil you use to take notes. The good news is that there are ways to meet our needs and tread more lightly on the Earth.

What do paper, cinnamon, lumber, maple syrup, rubber and medicine have in common? They all come from trees! That's because trees come in all shapes and sizes and many tree species provide important resources for humans. Even if you don't live near a forest, trees still touch your life. As put by the United Nations Department of Economic and Social Affairs, "Over 1.6 billion people depend on forests for timber, food, fuel, jobs, and shelter, but all of us depend on forests in one way or the other."

But that's just a fraction of the natural medicine that grows in the forest. From roots pushing deep underground to wood mushrooms growing out of tree trunks high up above, forests are filled with medicine that can help with many of the things that ail humankind. Trained herbalists, indigenous healers, and others who live in close connection to the forest know what plants can stop bleeding, ease a headache, draw out a bee sting, disinfect wounds and more!

From clean water to clean air and proven health benefits, forests are crucial for the planet and for our well-being. That's because trees use their leaves to filter tiny particulate air pollutants, absorb and then gradually release rainwater, produce powerful chemicals and positive ions that help us release stress and anxiety, and so much more.

Deforestation, or the act of cutting down a forest to make room for other land uses, is a big challenge. So many forests are being cut down that it's making the planet sick and posing a danger to life on Earth. Fewer trees also means less rainfall and more drought — and many animals and plants face extinction as their forest homes are destroyed.