• rainforests are characterized by high rainfall, and by definition have a normal annual rainfall between 68 inches to 78 inches, or more.(1750 mm and 2000 mm)

Rainforests are home to two-thirds of all the living flora and fauna species on the planet.

It has been estimated that many hundreds of millions of new species of plants, insects and microorganisms are still undiscovered.

A forest is an area with a high density of trees.

Typical Tropical Rainforest Climograph

• temperature• precipitation

Can you tell which

hemisphere this rainforest is

within?

Southern Hemisphere

Tropical Rainforests are forests that form near the equatorial regions on the Earth…and fit the general rainy nature of the definition.

Average Temperature:

22° C (72° F)

Annual precipitation:

50-260 in.

As you can see from the bar

graph, rainforests are the wettest

biomes on Earth.

Mt. Waialeale is thought to be the wettest spot on earth, receiving well over 400 inches of rain a year!

Temperate Rainforests can be found in North America including the northwestern coast of the United States and the Pacific coast of Canada.

The temperate rain forest has seasonal variation, with summer temperatures rising to about 80°F and winter temperatures dropping to near freezing. In the northernmost regions, winter may be cold enough for some ice and snow.

• The tropical rainforest is a region of year-round warmth. • Almost all rainforests lie near the equator.• Rainforests are now one of the most endangered biomes, and cover less than 6% of Earth's land surface. But they are home to over 50% of all known species of living organisms.

• Tropical rainforests produce much of the oxygen for Earth’s atmosphere.

• Tropical Rainforests have very nutrient-poor soil, and are second only to deserts for this.

• Curare, from a tropical vine, is used as an anesthetic, and to relax muscles during surgery.

• Quinine, from the cinchona tree, is used to treat malaria.

• More than 1,400 varieties of tropical plants are thought to be potential cures for cancer.

• A person with lymphocytic leukemia has a 99% chance that the disease will go into remission because of the rosy periwinkle.

Emergent trees:are widely spaced, and 100 to 120 feet tall with umbrella-shaped canopies that grow above the forest. Because emergents are exposed to drying winds, they tend to have very small leaves.

This is an adaptation similar to what you would find in the desert, and it is helpful in conserving water for the plant.

The upper canopyof 80-foot trees allows light to be easily available at the top of this layer, but greatly reduced below it.

The upper canopy is home to many arboreal animals

In the lower canopy:At the 60-foot level, there is little air movement. As a result the humidity is constantly high in this area.

As you move down through the canopy, life becomes even more abundant

Besides these three canopy layers, a shrub/sapling layer receives about 3 percent of the light that filters in through the canopies.

• The ground layer: Sparse plant growth. Less than one percent of the light that strikes the top of the forest penetrates to the forest floor. Most areas of the forest floor receive so little light that few bushes or herbs can grow there. As a result, a person can easily walk through most parts of a tropical rain forest.

These stunted trees are capable of a sudden growth surge when a gap in the canopy opens above them.

If the leaf canopy is destroyed or thinned for any reason, the ground beneath is soon colonized by a dense tangled growth of vines, shrubs and small trees called jungle.

The air beneath the lower canopy is always humid. The trees themselves give off water through the stomata of their leaves. This process, called transpiration, can account for as much as half of the rain in the Amazon rain forest!

El Yunque in Puerto Rico

Emergent Trees: tiny leaves that allow them to combat the drying effects of the sun and wind they are exposed to. With between 100-200 inches of rain per year, some plants have adaptations that help them shed water off their leaves. Many plants have drip tips and grooved leaves for this purpose. Trees from the lower canopy, and rainforest floor have enormous leaves.

Some plants grow in the upper canopy on larger trees to get sunlight. These are the epiphytes such as orchids and bromeliads. Many trees have buttress and stilt roots for extra support in the shallow, wet soil of the rainforests.

The adaptation of prehensile tails (tails that can grip an object, and as such be used as an appendage) is only seen in New World monkeys. Monkeys from the Old World do not have this adaptation.

Other characteristics are bright colors and sharp patterns, loud vocalizations, and diets heavy in fruits.

Old World: Africa and Asia

New World: South America

Insects make up the largest single group of animals that live in tropical forests. They include brightly colored butterflies, mosquitoes, frogs camouflaged stick insects, and huge colonies of ants.

As said earlier, scientists estimate that more than half of the entire world's plant and animal species may live in tropical rain forests!

How do you know?

Tropical Rainforests

Temperate Rainforests