Forest facts for kids

This page is about a community of trees. For other uses, see Forest (disambiguation).

The Amazon rainforest alongside the Solimões River is a huge tropical rainforest. These forests have amazing biodiversity and are full of life.

A map showing where different types of forests grow around the world.

A forest is a large ecosystem packed with many growing trees. It is also an active ecological community where plants, animals, and tiny organisms live together. Forests cover about 31 percent of the land on Earth. The Food and Agriculture Organization (FAO) defines a forest as an area of land larger than half a hectare. The trees must stand taller than five meters, and their leafy tops must cover at least ten percent of the sky.

Forests are the largest land-based terrestrial ecosystems on our planet. They grow in many regions, from steamy tropical regions to freezing lands near the Arctic. In fact, nearly half of all forest land sits in the warm tropical latitudes. Forests make up about 75 percent of the gross primary production created by the world's living biosphere. They also store about 80 percent of all plant biomass found on land.

These amazing green spaces help our planet stay healthy. Forest trees take in carbon dioxide from the air and make oxygen for living creatures. They provide vital homes for millions of species. Forests also supply humans with useful resources like wood, food, and medicines. Caring for our forests helps protect Earth's climate and future.

How Do Scientists Define a Forest?
The Long History and Names of Forests
Forest Ecology and Earth's Climate
Inside the Layers of a Forest
Exploring Major Forest Types
Where Are the World's Forests?
Protecting Forests and Wildlife
See also
Images for kids
See also

How Do Scientists Define a Forest?

The Adirondack Mountains in Upstate New York are filled with trees that belong to the northern taiga biome.

People use more than 800 different definitions for a forest around the world. Most people think of a forest as a place full of living trees. However, some official rules define a forest by land use or legal boundaries. An area might still be labeled as a forest even if fires or storms recently cleared the trees away.

Experts usually group forest definitions into three main types. Administrative definitions are legal terms created by governments. Land-use definitions focus on what humans do with the land, such as harvesting timber. Land-cover definitions look at the actual trees on the ground. They measure tree density, height, and how much shadow the canopy casts over the earth below.

Different definitions also set boundaries between a forest, a woodland, and an open savanna. In some classification systems, a forest must have tightly packed tree branches that hide 60 to 100 percent of the sky. Other systems count areas as forest if just ten percent of the ground is shaded by tree branches. Some tree farms, like fields of Norway spruce grown as holiday trees, are legally treated as agricultural crops instead of wild forests.

The Long History and Names of Forests

The ancient Niepołomice Forest in Poland has been protected and used by people since the 13th century.

The modern English word forest comes from an Old French word that meant a vast open woodland. Long ago, the Normans introduced this term into England as a legal phrase. It described wild hunting grounds kept specifically for the king and feudal nobility. Latin documents like the famous Magna Carta referred to these royal reserves as a royal forest.

Interestingly, an ancient hunting forest did not always have dense trees covering every acre. Over many centuries, the word changed its meaning. People began using it to describe any large piece of land packed with wild trees. Older English words like weald, wold, and frith also described leafy woods and hunting lands. Many Romance languages took their words for woods from the Latin term silva, which is still linked to the science of silviculture.

The very first true forests on Earth appeared during the Middle Devonian period, roughly 390 million years ago. Early tree-like plants such as Calamophyton grew along ancient wetlands. Later in that period, a famous primitive tree named Archaeopteris developed wide green fronds. It reached heights of over 20 meters and quickly spread across prehistoric lands.

Archaeopteris behaved like a modern deciduous tree by dropping leafy branches onto the ground. This fallen material formed rich soil and leaf litter for the very first time. Decaying leaves also washed into ancient rivers, slowing currents and providing meals for early freshwater fish. These primitive plants created the world's very first woodland shelters.

Forest Ecology and Earth's Climate

A lush Temperate rainforest growing in Tasmania's scenic Hellyer Gorge.

Forests play a giant role in the field of forest ecology. They are responsible for huge amounts of plant biomass, which is the total weight of living plant matter. Much of this plant matter exists underground in deep root systems. Decaying roots and leaves produce organic debris known as detritus. Wood contains a tough natural material called lignin, which breaks down much slower than softer plant parts like cellulose.

Forests also protect the atmosphere by functioning as a massive carbon sink. A healthy forest absorbs carbon and stores it in living trunks, branches, roots, and soil. When trees stay healthy and keep growing, they lock away gases that would otherwise warm our climate. Scientists calculate that forest soils hold almost half of all woodland carbon.

Trees can also change local weather patterns. For example, huge trees in the Amazon rainforest pump water vapor from their leaves into the atmosphere. This moisture rises, cools, and triggers clouds to create early seasonal rainfall. Without these dense stands of trees, local areas could face severe drought. A drying forest can lose trees quickly, changing into open savanna.

Inside the Layers of a Forest

Tall beech trees create an old-growth stand in the scenic Sonian Forest near Brussels.

A forest is made up of living parts, like plants and animals, and non-living parts, like soil, rocks, and water. Fungi in the soil build underground threads called mycelium. These threads create a huge mycorrhizal network that connects tree roots together. This underground web lets plants share water and minerals across the forest.

Tall forests have several distinct horizontal layers. Each layer receives different amounts of sunlight and rain, creating unique homes for wildlife:

The forest floor is the ground level, covered in fallen leaves, twigs, and rotting logs. Hungry detritivores break down this waste to build rich dirt. Many small creatures, such as ants, spiders, millipedes, and amphibians, search for meals here.
The understory sits just above the ground and stays fairly dark. It includes shade-loving shrubs, ferns, and young saplings waiting for extra sunlight.
The canopy acts like a giant green roof made of leafy tree crowns. It catches most of the bright sunlight and makes food through photosynthesis. Many birds, insects, and climbing arboreal animals live high up in these branches.
The emergent layer contains giant trees that push far above the main canopy. These huge trees brave strong winds and bright sunshine in tropical rain forests.

Exploring Major Forest Types

A unique spiny forest growing at Ifaty in Madagascar, home to unusual baobab trees.

Scientists group forests into different categories based on their local climate, elevation, and tree varieties. Some trees are evergreen, keeping their needles or leaves all year. Other trees are deciduous, dropping their leaves when cold or dry seasons arrive.

Here are the main forest groups found around our globe:

Boreal forests: Also called taiga, these cold forests grow across northern regions like Canada and Russia. They are filled with hardy needle-leaved trees like spruce, firs, and pines.
Temperate broadleaf and mixed forests: These woodlands enjoy four distinct seasons with warm summers and cold winters. They feature trees like oak, maples, and beeches, and grow across parts of North America, Europe, and eastern Asia.
Temperate coniferous forests: These stands feature tall evergreen trees. They often thrive near coastal areas with plenty of rainfall, including famous temperate rainforests.
Tropical moist forests: Located near the warm equator, these lush wonderlands get rain throughout the year. They include the legendary Amazon Basin and the wild Congo Basin, which hold thousands of colorful animal species.
Tropical dry forests: These tropical woods face months of dry weather each year. Many trees shed their leaves to save precious water until heavy rains return.
Plantations: These are human-planted forests where workers plant trees in neat rows. People grow them like crops to harvest timber, building materials, and paper pulpwood.

Where Are the World's Forests?

A map showing what fraction of land is covered by forest in each country.

Forests cover about 4.14 billion hectares across the planet. However, these trees are not spread out evenly. More than half of the world's forests grow inside just five large nations: Russia, Brazil, Canada, the United States, and China. Some places, such as Monaco and Gibraltar, have almost no forest land at all.

Sadly, humans have cleared many forests over hundreds of years. Deforestation happens when people cut down or burn woods to clear land for farming, cattle, and cities. Many woodlands have also been split into smaller pieces, which hurts wildlife. Today, people are working hard to protect remaining trees and plant new woodlands through careful forest management.

Protecting Forests and Wildlife

Snowy peaks and evergreen trees at Garibaldi Provincial Park in British Columbia, Canada.

Forests provide helpful resources known as ecosystem services. They clean dirty air, keep drinking water pure, and prevent soil from washing away during a flood. Visiting a woodland also helps people feel calm, healthy, and happy. In many cities, community leaders look after trees through urban forestry programs in public parks.

Many Indigenous communities have looked after woodlands for hundreds of generations. Their traditional practices help maintain high biodiversity and protect old trees from harm. Today, countries are setting up more protected parks to safeguard wild areas. By using wood wisely, fighting wildfires, and planting new trees, people everywhere can help protect Earth's majestic forests.