Understanding Habitat and its changes


What are Habitats

Habitats are places where plants and animals live. They are natural environments where the species of the earth live, find food, shelter, protect themselves and reproduce. Habitats have physical and biological features.

Definition: A habitat is the natural environment of an organism, type of place in which it is natural for it to live and grow. A habitat offers an organism a home where the right conditions exists for it to survive, eat and reproduce. The plants get the right combination of light, air, water and soil.

A habitat could be a coral reef.
It is habitat for marine life.
A habitat could be a rotten log .
It is habitat for decomposers such as earthworms, fungi, and bacteria.

Learn more about how living organisms live on rotten logs. Click here.

A parasitic organism has as its habitat in the body of its host.
This heap of rocks or stones can also be the habitat for reptiles such as snakes, salamanders, and invertebrates such as spiders and crickets.These rock piles hold heat and cold longer than the air around it.

World Habitat Day

The United Nations designated the first Monday of October of every year as World Habitat Day to reflect on the state of our towns and cities, and on the basic right of all to adequate shelter.

Activity: Walk around your home and observe the wildlife around you in their habitat.

Colouring Sheets

Categories of Habitats

There are five major biomes, areas with similar characteristics, found in the world. These five types of habitats are aquatic, desert, forest, grassland, and tundra.

Terrestrial habitat types include forests, grasslands, wetlands and deserts. Each vary in climate, temperature, soil, and vegetation types. Each have its own typical communities of plants and animals.

Deserts areas like those in the Grand Canyon have scarce precipitation.
Deserts are the driest areas on earth.
Forest and woodlands are habitats with trees.
There are different types of forests, such as temperate and tropical.
The grassland habitat is dominated by grasses, few large trees or shrubs.
Tundra habitats has low temperatures, short vegetation, long winters, brief growing seasons, and limited drainage.

Aquatic biome includes the seas and oceans, lakes and rivers, wetlands and marshes, lagoons and swamps, mangroves, slat marshes, and mud flats.

Lakes such as this one is a freshwater habitat.
Marine habitat include brackish water, estuaries, bays, the open sea, the inter-tidal zone, sea bed, reefs, and deep or shallow water zones.

Learn more about habitats. Click on this link.

Picture source

Habitat changes

All parts of the ecosystem are connected. One part changes, and it affects the rest of the system. Each part of the habitats are generally not always the same.

In the spring and summer, plants emerge and grow; as it gets colder, many plants die off, lose their leaves, and many go dormant until the next seasonal growing period.
Extinct animals.
Some species disappear, and others take its place.

Here is a video about one of the above animals, the Tasmanian Tiger.

Placing a road through areas, or a building changes habitats and affect the biodiversity.

Note: Biodiversity – describes the many different species that share one habitat.

When biodiversity is threaten, there you will see the effects on the environment. Habitats change over time. Some main causes are:

  1. A violent event;
  2. Gradual changes that occur over millennia such as climate change;
  3. Weather pattern changes;
  4. Human activities cause changes; and
  5. The introduction of alien species can have devastating effect on native wildlife.
Violent events are volcano, earthquake, tsunami, wildfire, and change in oceanic currents
Human activities affect the environment.

Below is a video on factors that cause changes in a habitat. Take your notes.

The introduction of alien species can have devastating effects on native wildlife. The Lion fish was introduced into the sea waters of the Caribbean. This species is an addition predator for the local fish in that habitat.

Is it Worth Saving the Species?

Discussion question

Observe a habitat close to you. Review the essential components of the habitat: food, water, shelter, and space. How have human activity affect it?

Protecting Habitats

It is important to protect habitats. The lost of a habitat could be tragic. This threatens species diversity. Human activity, on the most part, can destroy, fragment or degrade a habitat. The main causes for habitat loss are:

  1. logging forests,
  2. oil and gas exploration and development,
  3. draining swamps and coastal habitats for development,
  4. road construction,
  5. cattle ranching,
  6. mining,
  7. pipelines,
  8. damming rivers and draining them for irrigation, and
  9. urban sprawl,

When a habitat is affected in such a way, it cannot provide the protection and needs that a species need to survive, live and raise their young. Affected habitats also threaten the future of humanity.

Urban sprawl refers to developments that spreads out over larges amounts of land. There is long distances between homes, stores, and work. Residential areas are separated from commercial areas. This type of development is burdensome on the ecosystem and encourages the displacement of much of wildlife.
Poaching is the illegal hunting, killing or capturing of any wildlife, in violation of local, state, federal or international conservation and wildlife management laws.
Bees are among the most important pollinators of wild plants and agricultural crops . However, they are in major decline largely due to the increased use of pesticides, changing and shrinking habitats and new diseases. Bee populations have been dropping 29%-36% every year since 2006. We depend on bees as they are vital to the agriculture.
Invasive alien species can be plants, animals, disease, fungi, parasites, insects, weeds, marine pests or other invertebrates and organisms. They threaten the biodiversity.

Humans threaten the ecosystem by being wasteful.

Wasteful, unsustainable, costly purchases put a strain on society. A throwaway society can be seen all around us: degraded lands, destroyed forest, filled landfills, and toxic dumps.

Protecting Habitats

One way of protecting habitats is by being frugal. We can hold on to somethings a little longer. To this, effort must be place on everyone being resourceful, producing and using products that last a lot longer.

Some more ways are:

Participate in a local trash clean-up to help protect the habitats of endangered species and wildlife.

Reduce, Reuse, and Recycle

Don’t throw it away if it still has a use! If you have unwanted books, toys, or clothes in good condition, consider giving them to charity instead of throwing them in the trash.
Find out what’s recyclable in your area. Recycle everyday items such as aluminum cans, glass and plastic containers, and cardboard and paper products. Dispose of electronics and other potentially hazardous materials at collection centers that will handle them properly.

Plant native flowers, trees and bushes in your backyard.

Avoid chemical pesticides and fertilizers.

Leave wildlife animals alone! Do not remove them from their environment. These animals survive best in their own habitat.

Be an educated Consumer

Don’t buy products that cause harm to animals and habitats. Use products made from recycle paper, products that contain plastic micro-beads.

Never buy exotic animals, especially caught in the wild.

Support genuine effort for ecotourism, photo safaris, or community-based humane education programs.

Picture source

Aquatic Habitats

An aquatic habitat is a habitat with water. It includes areas that are permanently covered by water and surrounding areas that are occasionally covered by water.

Estuaries, rivers, and marshes are examples of aquatic habitats.

The water in the estuary contains small pieces of plants, detritus (waste or debris of any kind), microscopic organisms, and algae in the water. Water is more salty closer to the sea, less salty as you move up the river. Salt in the water makes the water heavier than freshwater. This is why it is easier to float in ocean water than a lake. At the bottom of an estuary, the soil or mud is thick and deep. Small organisms live and breathe in the top layers of mud, which contains some oxygen. Many plants live in different parts of the estuary. Some plants grow in marshes, their roots grow in the mud, and the stem submerged when the tide comes in.

Some plants and animals live completely underwater, such as the sea lettuce. Then there are plants and animals that float and drift in the water, such as phytoplankton and zooplankton. There are animals that live underwater, in the top layer of mud, such a oysters. There are some free-swimming, such as the striped bass.

Notes on Surface and Ground Water

Notes – Water Source

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Natural events affect aquatic environments.

Climate, weather, temperature change, drought and flooding are natural factors that affect estuaries and rivers.

Tides affect salinity (amount of salt ). Rising levels of ocean water at the shore pushes more saltwater up into the estuary and river. During low tide, ocean water draws back from the estuary.

Flooding causes the estuary to get more freshwater from the river. When a river floods it deposits nutrient rich sediment on the banks, bits of vegetation washes into the water and become food for aquatic organisms. Floods replenish lakes and ponds, it raises the water table.

Flood through extreme events can be detrimental to aquatic system until balance is reached.

Human Activities affect aquatic environments.

Human activities affect aquatic environment in the most disruptive way.

Humans affect aquatic habitats in activities such as oil sands, aggregate mining, forestry, wildlife hunting and tourism.

These activities affect the water cycle, interferes with the level of streams and flow of water, drain wetlands, and eliminate aquatic organisms. Some of these activities uses a lot of our water resources such as oil sands and mining.

Picture 1: Water pouring from a drain pipe to the river, polluting the environment. 2: Fossil fuel is burned and sulfur dioxide and nitrous oxide gases are release into the air. 3. These gases dissolve in raindrops that fall to earth as acid rain. It destroys plant and 4. flows into streams and lakes. Many species are unable to survive in this type of aquatic habitat.

When people build dams, they change freshwater ecosystems from a flowing system into a still system.

Dams can disrupt the reproductive cycles of organism. It causes water temperatures to be warm or cold. This confuses organism whose growth and reproduction is triggered by temperature changes. Many fish leave large lakes and oceans and swim up stream to lay their egg. Dams can keep these fish from reaching their spawning grounds.

All life is made of water and needs water. Water is our most threaten resource. The decreasing amounts and polluted, unsafe water is leading to sickness and death. This is the most important reason we should protect our aquatic habitats and all habitats.

Learn more of this under the topic of ecosystems and cycles.


Make a list of things that live in estuaries and rivers. Discuss how a few of these things would fare if the water they live in was saltier, or if there was a flood. Go to the CHAT. Click on the link below.

Suggested Activity

Essay: Write a short paragraph explaining why you think it is important to save Earth’s Coral reefs.


Click on the links below to download the PDF worksheets.