Global Biodiversity

Global Biodiversity

Biodiversity refers to the variety of living organisms within a given area.


6 - 12+


Biology, Ecology, Geography, Earth Science

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The word "biodiversity" refers to the number of different kinds of living beings found in a specific place. If biodiversity is high, then there are many different kinds of animals and plants.

Kinds Of Biodiversity

Biodiversity includes plants, animals and all other living things. One way to measure it is to count the total number of species living in an area. A specific type of animal or plant is called a species. For example, each cat is different from every other cat, but all cats belong to the species Felis catus. Dogs belong to the species Canis lupus.

There are different levels of biodiversity in different parts of the world. Tropical regions have the most biodiversity. These areas are warm year-round and get a great deal of rain. Large amounts of water allow many plants to grow and many animals to survive.

Temperate regions have less biodiversity. They have warm summers, but cold winters. Regions with very cold mountains or very hot and dry deserts have the least biodiversity.

Some places in the world have a large number of endemic species. An endemic species is one that exists only in that one place. For example, the Cape Floristic Region in South Africa has a huge number of endemic species. It is home to about 6,200 plant species found nowhere else in the world. If this one area was destroyed, all those species would be gone forever.

Importance Of Biodiversity

All species are interconnected. They depend on each other. Forests are homes for many animals. Animals eat plants. Bees and other insects carry pollen from one plant to another, which allows the plants to reproduce, or create new plants.

With less biodiversity, these connections weaken and sometimes break. When that happens, all the species in an ecosystem are harmed. An ecosystem is a community of living things that interact with each other.

Ecosystems with high biodiversity are usually stronger against disasters. For example, in the early 1900s, most of the chestnut trees in the eastern forests of North America were killed by a plant disease. The disease only killed that one type of tree, though. The forest ecosystem survived because it had many other kinds of trees too. If the forests had been nothing but chestnut trees, today there would be no forests.

Biodiversity is also important for humans. Plants help us by making the oxygen we need to breathe. They also provide food, shade, construction material, medicines and fiber for clothing and paper. Plant roots help hold the ground together and prevent flooding. Plants, animals and fungi, such as mushrooms, keep soil fertile and water clean. As biodiversity decreases, all these systems break down.

Decreasing Biodiversity

In the past hundred years, biodiversity has decreased around the world. Many species have gone extinct, or died out forever.

A major reason is that natural habitats are being destroyed. A habitat is a place that has the best qualities for a species to survive. For example, frogs need to live in or near water. So, ponds make good frog habitats.

Today, the fields, forests and wetlands where wild plants and animals live are quickly disappearing. People are clearing the land to plant crops or build houses and factories. Forests are cut for lumber and firewood.

Pollution, overfishing and overhunting have also caused a drop in biodiversity. The overall temperature has also been increasing around the world. This global warming is caused by human activities, such as burning gas and coal.

Global warming is causing all sorts of problems. For example, warmer ocean temperatures are damaging coral reefs. Coral reefs are home to countless underwater species. A single coral reef can shelter 3,000 species of fish and other sea creatures such as clams.

Scientists and others are doing what they can to protect biodiversity. Around the world, thousands of parks have been set up to conserve, or save, plants and animals. Within the United States, our national parks are helping to protect biodiversity.

Fast Fact

Species by the Numbers
Scientists have identified about 1.75 million different species. That includes 950,000 species of insects, 270,000 species of plants, 19,000 species of fish, 9,000 species of birds, and 4,000 species of mammals. This is only a small portion of the total number of species on Earth. There are millions more species yet to be discovered and named.

Fast Fact

Medicine from Nature
About 25 percent of the medicines used today are taken from or modeled on chemicals found in plants, animals, or other living things.

Fast Fact

Powerful Pollinators
Bees, birds, and other creatures pollinate 75 percent of the world's major crops. In areas with lots of biodiversity, insects and other creatures pollinate plants naturally. But when biodiversity is reduced, this is impossible. There are not enough insects to pollinate large fields of single crops, so farmers must truck in honeybees to do the job.

California almond farmers need about 1.5 million hives of honeybees to pollinate their crops. That's more than half of all the commercial beehives in the country.

Media Credits

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Melissa McDaniel
Santani Teng
Erin Sprout
Hilary Costa
Hilary Hall
Jeff Hunt
Diane Boudreau
Tara Ramroop
Kim Rutledge
Mary Crooks, National Geographic Society
Tim Gunther
Jeannie Evers, Emdash Editing, Emdash Editing
Kara West
Educator Reviewer
Nancy Wynne
National Geographic Society
Last Updated

October 19, 2023

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