Rainforests and

Coral Reefs

RAINFORESTS

What is a rainforest?

• Low elevation evergreen forest• Temperature between 65-75 degrees every

day of the year• At least 5 feet of rain every year• Two major types of rainforest:– Temperate rainforests– Tropical rainforests

Where are the rainforests?

• Rainforests can be found all over the world– As far north as Alaska and Canada to Latin

America, Asia, and Africa• Found on every continent, except Antarctica• Cover about 2% of the total surface of the

Earth• The Amazon rainforest is located in South

America

Where are the rainforests?

Where are the tropical forests?

• 47% of the world’s forests are tropical• Approximate distribution of the world’s

tropical rainforests– South America 58%– Africa 24%– Asia 17%– Central America 1%

Biodiversity

• Biodiversity—the number and variety of organisms found within a specified geographic region

• Also called “species richness”

Biodiversity in rainforests • Rainforests are home to 50% of all of the

species of plants and animals on Earth • A typical 4 square mile patch of rainforest

contains as many as:– 1,500 flowering plants– 750 species of trees– 400 species of birds– 150 species of butterflies

• More than 2,000 different species of butterflies are found in the rainforests of South America

Interesting facts

• Trees in a tropical rainforest can be so close together that rain falling on the top canopy can take as long as 10 minutes to reach the ground

• In the rainforest, an area the size of a football field is being destroyed every second

• 80% of the flowers in the rainforests in Australia aren’t found anywhere else in the world

• Flying animals of Asian rainforests include frogs, squirrels and snakes

Why are rainforests important?

• Rainforests help to regulate temperatures and weather patterns

• 20% of the world’s fresh water is found in the Amazon Basin

Why are rainforests important?

• Rainforests provide many important products for people– Wood, coffee, cocoa, chewing gum

• Many medicines are made from things found in rainforests– 1 in 4 ingredients in our medicine come from

rainforest plants – More than 2,000 rainforest plants have anti-

cancer properties

Threats to rainforests• Rainforests are threatened by:– Unsustainable agricultural– Ranching– Mining– Logging

• More than 56,000 square miles of natural forest are lost each year

• Approximately 2,000 trees are cut down in the rainforest every minute

CORAL REEFS

What are coral?• Living organisms, called polyps• Two main types of coral– Hard corals– Soft corals

• Can live on their own, but are usually associated with the communities, called reefs, that they construct

• Invertebrates– Tiny, soft-bodied with a hard, protective skeleton at their

base– Related to sea anemones and jellyfish

• Get most nutrients from algae, but can also eat zooplankton and even small fish

What is a coral reef?

• Called the “rainforests of the sea”– Next to rainforests, coral reefs are among the

most diverse ecosystems in the world• The largest living structures on the planet• Among the oldest ecosystems in the world

Where are coral reefs?

• Coral reefs only occur in the tropics• Most are in the Pacific ocean region• The largest is the Great Barrier Reef in

Australia• Shallow waters– Require sunlight because the algae that live on the

reefs do photosynthesis• Occur only in clear waters with low nutrients– Are harmed by nutrient loading

Where are coral reefs?

Biodiversity in coral reefs

• Even though coral reefs cover less than 1% of the Earth’s surface, they are home to 25% of all of the fish species in the ocean

Interesting facts

• The Great Barrier Reef is the only natural structure that you can see from space

• There are more than 2,000 coral reefs in the world

• Full grown coral will eat little baby coral• Baby coral are smaller than a pinhead• No two reefs are exactly alike

Why are coral reefs important?

• 500 million people rely on coral reefs for food and their source of income

• Form natural barriers that protect nearby shorelines from the eroding force of the sea

• Without the existence of coral reefs, parts of Florida would be completely underwater

Why are coral reefs important?

• Provide $375 billion every year around the world in products and services

• Things from coral reefs have been used in medicine and the treatment of many diseases– Cancer– HIV/AIDS– Heart diseases– Ulcers– Human bone grafts

Threats to coral reefs

• Coral reefs are very sensitive• Coral reefs are threatened by– Pollution– Disease– Over-fishing– Dynamite and cyanide fishing– Sedimentation– Bleaching caused by rising ocean temperatures

Threats to coral reefs• Approximately 66% of all coral reefs are at risk

today– About 88% of the reefs in Southeast Asia (the most

species rich reefs in the world) are at risk• If the present rate of destruction continues,

70% of the coral reefs will be destroyed in the next 40 years

• Approximately 25% of coral reefs have already disappeared– Since 1975, more than 90% of the coral reefs in the

Florida Keys have lost their living coral cover