Nature · Earth Science
The green lungs of the Earth
A forest is a large area dominated by trees and the web of life they support. Covering about a third of the planet's land, forests store carbon, release oxygen, shelter most of the world's land species and regulate the water cycle — truly the lungs of the Earth.
Forests develop through succession: bare ground is first colonised by grasses and shrubs, which enrich the soil until trees can take hold and grow into a mature, layered canopy. The type of forest that results depends on climate — temperature, rainfall and latitude.
From the sunlit emergent trees and canopy down through the understorey to the shaded forest floor — each layer its own habitat.
Hot, wet and teeming with life
With constant warmth and heavy rain, tropical rainforests pack in more species than anywhere else on land, layering life from the forest floor to the towering canopy.
Forests of the four seasons
In mild mid-latitude climates, broadleaf trees like oak and maple leaf out in spring and blaze in autumn before dropping their leaves to survive the winter.
The vast northern conifer belt
Circling the globe below the Arctic, the taiga is a seemingly endless belt of hardy spruce, pine and fir that endures long, freezing winters — the largest forest on Earth.
Trees that root in the tide
Mangroves are salt-tolerant trees that thrive between land and sea, their arching roots trapping sediment, buffering coasts from storms and sheltering countless young fish.