A rainforest is an area of tall, mostly evergreen trees and a high amount of rainfall.
Rainforests are Earth’s oldest living ecosystems, with some surviving in their present form for at least 70 million years. They are incredibly diverse and complex, home to more than half of the world’s plant and animal species—even though they cover just 6% of Earth’s surface. This makes rainforests astoundingly dense with flora and fauna; a 10-square-kilometer (4-square-mile) patch can contain as many as 1,500 flowering plants, 750 species of trees, 400 species of birds and 150 species of butterflies.
Rainforests thrive on every continent except Antarctica. The largest rainforests on Earth surround the Amazon River in South America and the Congo River in Africa. The tropical islands of Southeast Asia and parts of Australia support dense rainforest habitats. Even the cool evergreen forests of North America’s Pacific Northwest and Northern Europe are a type of rainforest.
Rainforests’ rich biodiversity is incredibly important to our well-being and the well-being of our planet. Rainforests help regulate our climate and provide us with everyday products.
Unsustainable industrial and agricultural development, however, has severely degraded the health of the world’s rainforests. Citizens, governments, intergovernmental organizations, and conservation groups are working together to protect these invaluable but fragile ecosystems.
Most rainforests are structured in four layers: emergent, canopy, understory, and forest floor. Each layer has unique characteristics based on differing levels of water, sunlight, and air circulation. While each layer is distinct, they exist in an interdependent system: processes and species in one layer influence those in another.