A rainforest is a type of forest characterized by high rainfall and year round growth. Trees are a major component of the rainforest habitat and can reach an astounding height of over 200 feet. Most of the world’s rainforests are tropical, but some are temperate. Temperate rainforests exist in mild climates, and most are located in coastal areas where fog can deliver lots of moisture. In these rainforests, rainfall can reach up to 13.9 feet (4.2 meters) per year. The largest temperate rainforest in the world occurs along the Pacific coast of North America.

The world’s tropical rainforests are found near the equator between the Tropic of Cancer and the Tropic of Capricorn. Tropical rainforests exist in Central and South America, West and Central Africa, Southeast Asia, Pacific Islands, and northern Australia. The Amazon of Brazil, which lies in the Amazon River basin, is the world’s largest rainforest. Tropical rainforests can be dense, where rainfall is abundant year round; seasonally moist, where rainfall is abundant but seasonal; or drier and more sparse like the rainforests of northern Australia. Precipitation varies from 50 to 260 inches (125 to 660cm) a year and averages about 80 inches per year. Temperatures in tropical rainforests usually stay between 68 and 93 degrees Fahrenheit (20-34 degrees Celsius) and humidity is between 77 and 88 percent.

Tropical rainforests once covered 14% of the world’s land surface, but today only about 7% of the earth’s land surface (about the size of the United States) is covered with these forests. Tropical rainforests are unique because they contain a high level of biodiversity and release 20% of the worlds fresh oxygen to the atmosphere. This vital ecosystem is being destroyed at an astonishing rate. Every second, the equivalent of one football field of rainforest is destroyed.

Tropical rainforests are home to half of the world’s estimated 10 million plant and animal species. However, scientists can estimate the number of stars in the sky with more accuracy than they can estimate the number of species living in the tropical rainforest. To date, only 6% of the species living in the rainforest have been discovered. Of that 6% only a tiny proportion (about one sixth) has been intensively studied.

Each of the world’s rainforests maintains different levels and types of biodiversity. More than 250 different species of trees exist in 2.5 acres (or 1 hectare) of tropical rainforest. Each tree provides a habitat for hundreds of species. For example, up to 40-50 species of ants can live in one tree in Brazil.

There are more species of birds in the Peruvian rainforests than in the entire United States. Whereas, one small pond in Brazil can contain a larger variety of fish than all of the rivers in Europe combined. In fact, one bush or shrub in the Amazon rainforest can hold more species of ants than the entire British Isles. Tropical rainforests also contain over 95% of primates found nowhere else in the world. Many species found in rainforests are unique to a specific rainforest, or are uniquely indigenous to a specific area of one rainforest.

The biodiversity found in the world’s rainforests is invaluable. Currently, rainforest plants are the basis for many modern day medicines. The National Cancer Institute has performed research on rainforest plants in order to find plant-based cures for cancer. Of the 3,000 plants identified as having elements that could potentially cure cancer, 70% are found only in tropical rainforests. The rainforest is a resource with boundless possibilities but it must be protected in order for us to reap its benefits.

Tropical rainforests can typically be divided into four main layers, called strata. The four strata are: the Emergent Layer, the Canopy, the Understory, and the Floor. Each strata has its own community of plants and animals.

The emergent layer contains the tallest trees in the rainforest, like the Cuipo tree, which grow above the canopy, reaching heights of 55 meters or more. The trees in this layer produce thick waxy leaves in order to retain moisture and withstand heat. Eagles, monkeys, butterflies, bats, snakes and other rare animals inhabit this layer of the rainforest.

The canopy is the most well known level in the rainforest structure. This dense layer forms almost a complete cover over the lower layers. Even though the trees and leaves in the canopy barely touch and rarely interlock, the trees and leaves block out nearly all sunlight. The canopy is home to hundreds of animals that seek protection from predators on the forest floor. These animals swing and jump from tree to tree in search of food and shelter.

The understory lies between the canopy and the forest floor. This layer retains the most moisture and contains much larger leaves than the Canopy. As a result, the understory flourishes and thrives with life. It is home to a number of species including birds, snakes, lizards, and insects. Large predators such as jaguars, boa constrictors and leopards are found in this layer as well. Only about 5% of the sunlight shining on the rainforest reaches the understory.

The rainforest floor only receives about 2% of the sunlight that falls on the canopy. Due to the lack of light, there is little vegetation on the rainforest floor. Only a few plants have adapted to living in such conditions. The floor is littered with fallen branches, leaves and animal matter, all of which disappears quickly due to the warm and humid conditions. Fungi, insects and bacteria species living in this layer promote the decomposition process.

Just a few thousand years ago, tropical rainforests covered as much as 14 percent of the Earth's land surface, or about 6 million square miles (15.5 million square km). Today, less than 7 percent of Earth's land is covered with these forests (about 2.41 million square miles or 625 million hectares).

In recent history, much of the world’s tropical rainforest has been decimated by deforestation. The Amazon Rainforest has been specifically targeted, and is currently being deforested at an astonishing rate of 1.5 acres per second. Given that 80% of the earth's biodiversity comes from tropical rainforests, deforestation has devastating affects on the earth's insect and animal life.

Nearly 20 years ago, Harvard’s Pulitzer Prize-winning biologist Edward O. Wilson described deforestation and its impact on the planet: “The one process ongoing in the 1980’s that will take millions of years to correct is the loss of genetic and species diversity by the destruction of natural habitats. This is the folly that our descendants are least likely to forgive us for.”

Scientists estimate that we lose over 137 species of animals and plants every day due to deforestation. Commercial logging is the greatest cause of rainforest deforestation. Commercial logging companies buy plots of land in the rainforest to cut down the trees and sell the timber. The wood that is not sold to commercial companies is used for fuel. Once the trees are removed, much of the rainforest property is converted into grazing land for animals like cattle, goats and pigs. As a result there is no re-growth of the deforested areas.

Climate change has adversely affected the temperature and amount of rainfall in many of the tropical and temperate rainforests. Should sea levels continue to rise, due to the result of changing climates, the coastal areas of the rainforest will be severely affected. Historically, rainforests have been able to recover from climate changes, as they have for millions of years; however, deforestation and fragmentation of rainforests in recent years has made rainforests significantly less resilient.

Want to be a part of the solution? Act now to save the rainforest.

Cuipo puts on educational assemblies about the rainforest and the affects of deforestation for students of all ages. Want Cuipo to come to your school? Contact gogreen@cuipo.org for more information!