Habitat

In ecology, a habitat is the place where a plant, animal, or other organism lives and finds everything it needs to survive. It includes the things around it, like the soil, water, temperature, and light, as well as other living things, such as its food and possible dangers. Every kind of organism needs a specific habitat to live well. Some can live in many different places, while others need just one special spot.

This coral reef in the Phoenix Islands Protected Area provides habitat for numerous marine species.

Habitats can be very different depending on where they are. For example, forests, grasslands, and deserts are all land habitats. Water habitats include places like lakes, rivers, and the ocean. Each habitat supports many kinds of plants and animals that have adapted to live there.

Habitats can change over time. Natural events like volcanoes, earthquakes, or big fires can change a habitat quickly. Slower changes happen because of shifts in climate or ice moving. Human actions, such as cutting down forests or changing water paths, can also change habitats. These changes can affect the animals and plants that live there, sometimes making it hard for them to survive.

Definition and etymology

The word "habitat" has been used since around 1755. It comes from a Latin word meaning "to inhabit," which means to live somewhere. A habitat is the natural home of a living thing, like a plant or animal, where it can live and grow. This is similar to a biotope, an area with the same conditions where certain plants and animals live together.

Environmental factors

The main things that affect where plants and animals live are temperature, humidity, climate, soil, and how much light there is, along with everything else an organism needs to survive. Animals usually live where certain plants grow.

Some plants and animals can live in many places. For example, the small white butterfly can be found everywhere in the world except Antarctica. Its babies eat many types of plants and can live in open areas with lots of plants. Other animals, like the large blue butterfly, need very special places to live. This butterfly only lives in chalk grassland areas where its babies can eat certain plants and where specific ants live.

Disturbances, like lightning strikes or storms, help create spaces where new plants and animals can grow. Without these disturbances, one type of plant might take over and stop others from growing. This is why areas like wildflower meadows, tropical forests, and coastal regions stay full of different kinds of life.

Types

Terrestrial

Terrestrial habitats include places like forests, grasslands, wetlands, and deserts. Each of these areas has its own special plants and animals. Some habitats blend into each other, and each one usually has its own group of living things that call it home.

Arid

Rich rainforest habitat in Dominica

Arid habitats have very little water. The most extreme example is the desert. Animals in deserts have special ways to survive with so little water. Some frogs live underground in deserts and come out only when it rains. They lay eggs in the temporary pools that form after a storm, and their baby frogs grow quickly and then hide away again.

List of arid habitat types

Wetland and riparian

Some animals and plants live in places that can dry out, like small ponds that appear after rain and disappear later. These places have special plants and animals that can survive the dry times. Some tiny shrimp can lay eggs that stay alive even when the water is gone, and these eggs can wait many years before they grow.

Examples of wetland and riparian habitat types

Desert scene in Egypt

Forest

Examples of forest habitat types

Freshwater

Wetland habitat types in Borneo

Freshwater habitats include rivers, streams, lakes, ponds, marshes, and bogs. These can be places where water moves, like rivers, or places where water stays still, like lakes. Different animals and plants live in these places depending on how fast the water moves, how warm it is, and how much oxygen it has.

Marine

Marine habitats include places like salty water areas, estuaries, bays, the open ocean, areas where land meets water, the sea floor, reefs, and shallow or deep water zones. These areas have many different plants and animals. Some live on the sea floor, some float near the surface, and others swim at different depths.

List of marine habitat types

Urban

Many animals and plants live in cities. They are usually very adaptable and use buildings and other city features for their homes. Rats, mice, pigeons, bats, foxes, squirrels, coyotes, raccoons, and skunks are some examples of animals that live in urban areas. Some even make nests in the roofs of houses.

Microhabitat types

"Microhabitat" redirects here. For the South Korean film, see Microhabitat (film).

The leaves of an Alnus nepalensis tree provide a microhabitat for species like the leaf beetle Aulacophora indica.

A microhabitat is the small area where a specific plant or animal lives. Every big habitat, like a forest, has many tiny microhabitats that are a little different from each other. These differences can be in light, moisture, temperature, or air movement.

For example, lichens growing on the north side of a rock are different from those on the south side, top, or ground nearby. Even small spots like grooves or raised parts of a rock can have different lichens. Tiny animals, called microfauna, also live in these microhabitats, each needing its own special spot. Forests have many types of microhabitats, from tree trunks to leaf litter, providing homes for many different plants and animals.

Extreme habitat types

Main article: Extremophile

An Antarctic rock split apart to show endolithic lifeforms showing as a green layer a few millimeters thick

Most life on Earth lives in places with moderate conditions, but some tiny organisms, called microbes, can survive in very harsh places. For example, there are bacteria living half a mile below the ice in Antarctica and in the deepest parts of the ocean, like the Mariana Trench. These bacteria don’t have sunlight, so they get food from decaying matter or minerals.

Dense mass of white crabs at a hydrothermal vent, with stalked barnacles on right

Some microbes live where there is no oxygen, using chemical reactions instead of sunlight to survive. They can be found deep in rocks or mines, where they use tiny amounts of hydrogen to live. These places were once thought to be too harsh for any life.

Hydrothermal vents, found deep in the ocean, were discovered in 1977. These hot springs heat seawater to very high temperatures and support unique life forms. Microbes there use chemicals like hydrogen sulfide to create food, supporting many animals like molluscs and worms.

The atmosphere also supports tiny microbes that live and reproduce in the air. There are many examples of extreme habitats where specially adapted life exists, such as tar pits, hot springs, and salt pans, each hosting unique microorganisms.

Habitat change

Twenty-five years after the devastating eruption at Mount St. Helens, United States, pioneer species have moved in.

Habitats can change over time due to both natural events and human activities. Natural changes include slow shifts in land shape and faster events like earthquakes, storms, and wildfires. Human actions such as farming, building, and pollution also change habitats.

When habitats are lost or divided, it can threaten the animals and plants that live there. For example, cutting down forests into smaller pieces can make it hard for animals to move between areas, putting them at risk. Connecting these pieces with paths or strips of natural land can help protect wildlife. Changes in habitats can also affect the balance of plants and animals, sometimes leading to unwanted plants taking over or animals changing how they live.

Habitat protection

Protecting habitats is very important for keeping many kinds of animals and plants alive. If their homes are destroyed, these creatures can suffer. Many countries have laws to help protect wildlife. These laws can create special areas like national parks or wildlife reserves. They can also stop people from doing things that harm animals and plants, like hunting or taking away eggs.

Sometimes, laws focus on protecting special animals that are in danger. Other times, they protect whole areas where many different animals and plants live. International agreements can help protect animals that travel between countries. However, even with laws, protection isn't always easy. Local people may need to use the land for food or other needs, which can sometimes hurt wildlife habitats. Teaching local communities about the value of their natural surroundings can help protect both people and nature.

Monotypic habitat

A monotypic habitat is a special kind of place where only one type of plant or animal lives, making it different from other areas with many types of species. Even though it may seem like such a place doesn’t have much variety, it can still support many tiny creatures. For example, a single type of plant called Hydrilla can host lots of small animals, just like more mixed areas do. Sometimes, plants or animals that are not native to an area can take over and create their own monotypic habitat, stopping other species from growing there. One example is the yellow starthistle, Centaurea solstitialis, which now covers huge areas in California. Another example is the zebra mussel, Dreissena polymorpha, which has taken over parts of the Great Lakes and the Mississippi River watershed.