To deforest means to clear away trees from a large area of land, usually permanently. When a forest is deforested, the trees are cut down or burned to make room for farms, cities, roads, or other human uses.

Throughout history, humans have deforested enormous areas. Ancient civilizations deforested lands around the Mediterranean Sea for agriculture and shipbuilding. European settlers deforested much of the eastern United States to create farmland. Today, tropical rainforests in places like Brazil and Indonesia are being rapidly deforested, often to grow crops or raise cattle.

Deforestation isn't the same as selective logging, where some trees are carefully harvested while the forest remains. When an area is deforested, the entire forest ecosystem disappears.

Scientists worry about deforestation because forests play crucial roles: they produce oxygen, provide homes for countless species, prevent soil erosion, and help regulate Earth's climate. Once a forest is gone, it can take centuries to grow back, if it grows back at all.

The related word reforestation means planting trees to restore a deforested area. Some countries now work to reforest lands that were cleared decades or centuries ago, though creating a new forest takes patience and careful planning.