Rain Forest

How Rain Forests Develop

Kinds of Rain Forests

Climate

Geography of Rain Forests

Plant Life

Animal Life

Human Life

The Food Web

Spotlight on the Rain Forests

For More Information

A tree is a woody plant with a single, strong trunk and many branches that lives year after year. A large group of trees covering at least 25 percent of the area where the tops of the trees, called crowns, interlock to form an enclosure, or canopy, at maturity make up what is called a forest. The term rain forest is used to refer to any forest in tropical or semitropical regions. (Tropical regions are those around the equator.) Rain forests occur in a few regions with temperate (moderate) climates.

Tropical rain forests, also called jungles, are located for the most part in the belt between the tropics of Cancer and Capricorn. The term jungle usually indicates a disturbed, tangled, tropical rain forest with vines and other distinct plant and animal life. Plenty of rain and warm temperatures year-round support constant plant growth and great diversity of species. It is estimated that there are up to 260 different kinds of trees per square mile of rain forest. Trees that would normally lose their leaves during the autumn season in cooler climates retain them for several years (some trees for up to sixteen years), becoming evergreens because there are no cold and warm seasons. Rain forests cover only about 7 percent of Earth’s surface, or 4.4 million square miles (11.5 million square kilometers) of land.

Tropical evergreen rain forests occur in four main regions:

• The Americas and the Caribbean
• Africa and Eastern Madagascar
• India and Malaysia
• Australia

How Rain Forests Develop

The first forests evolved during Earth’s prehistoric past. Since then, all forests have developed in essentially the same way, by means of a process called succession.

The first forests

The first forests were very different from those found today. They were mostly composed of huge ferns and clubmosses; there were no flowers to speak of. Flowering plants developed only 65 to 145 million years ago during the Cretaceous period. Among the first to evolve were the ancestors of modern water lilies. Present day rain forests began developing shortly after the flowering plants.

Succession

Trees compete with one another for sunlight, water, and nutrients, thus a forest is constantly changing. The process by which one type of plant or tree is gradually replaced by others is called succession. Succession can occur naturally when different species of trees become dominant as time progresses and the environment changes. It can also occur from natural disasters, such as forest fires.

Primary succession

Primary succession of some forests in North America usually begins on bare soil or sand where no plants grew before. When the right amount of sunlight, moisture, and air temperatures is present, seeds begin to germinate (grow). These first plants are usually made up of the grasses and forbs (a nonwoody broad-leaved plant) type. They continue to grow and eventually form meadows. Over time, and as conditions change,

other plants begin to grow such as shrubs and trees, which become dominant and replace or take over where the grasses and forbs originally grew.

As primary succession continues, “pioneer” trees that are tall and sun-loving quickly take over the meadow. They change the environment by making shade. Trees with broader leaves that prefer some protection from the sun can then take root. If conditions are right, a mixed forest of sun-loving and shade-loving trees may continue for many years. Eventually, more changes occur.

The climax forest

Seedlings from pioneer trees do not grow well in shade; therefore, new pioneer trees do not grow. As the mature trees begin to die from old age, disease, and other causes, the broad-leaved trees become dominant. The shade from these broad-leaved trees can be too dense even for their own seedlings. As a result, seedlings from trees

that prefer heavy shade begin to thrive and eventually dominate the forest. These trees produce such deep shade that only trees or plants that can survive in complete shade will succeed there. When this happens, the result is a climax forest.

Few true climax forests actually exist because other changes take place that interfere with a forest’s stability. Fires, floods, high winds, and people can all destroy a single tree to acres of trees. Glaciers can mow them down; volcanoes can smother them with ash or molten rock or knock them over with explosive force. Then the process of succession starts over.

Secondary succession

When the land has been stripped of trees, in some areas it will eventually be covered with them again if left alone. This is called secondary succession and can take place more quickly than primary succession. Seeds from other forests in neighboring regions are blown by the wind or carried by animals to the site. The seeds take root, seedlings sprout, and the process begins again.

Kinds of Rain Forests

Tropical evergreen rain forests can be classified into three main types: lowland, montane, and cloud.

Lowland wet forest

Lowland wet forests thrive close to the equator where rainfall is heavy, at elevations from sea level up to 4,000 feet (1,200 meters). They occur widely in the Asian tropics, in South America near the Amazon, and in Africa. Vegetation is wide and varied in these forests, having as many as 2,000 different species of trees. The largest lowland wet forest is currently located in Brazil (commonly known as Selva, the Spanish word for forest). Studies show that the Amazon forest may contain up to 120 different species in one acre of forest.

Montane rain forest

The true montane, or mountain, rain forests begin where lowland wet forests leave off; about 4,000 feet above sea level. There are lower and upper montane forests at lower and higher altitudes respectively. The average temperature is 66°F (19°C), and oak and laurel trees are predominant. At higher altitudes (upper montane) the cooler weather is favored by coniferous trees and myrtles. Montane forests can be found in Africa, Papau New Guinea, and South America.

Cloud forest

Cloud forests, such as those in Costa Rica, grow on mountains but usually at altitudes higher than 5,000 feet (1,500 meters). Their name comes from the fact that low-lying clouds form around them, shrouding them in mist. At about 10,000 feet (3,000 meters), the upper cloud forest is known as the elfin forest. The trees, including some species of pines, tend to be stunted and more twisted than those at lower elevations. Mosses, ferns, and lichens are abundant throughout this forest.

Climate

The climate of a tropical rain forest is warm and humid all year long. Average annual temperatures are between 68° and 84°F (20° and 29°C), and the temperature never drops below 64°F (18°C). There is almost no seasonal temperature change because the difference between the coldest and warmest months is only 3°F (1°C).

Rainfall varies throughout the tropics, with some areas receiving as little as 60 inches (1.5 meters) annually, and others twice that amount. Dry seasons occur, especially in monsoon climates. Some precipitation (rain) falls almost every day. It may come in a thunderous downpour or in a misty shower. In general, humidity is very high, and days are often cloudy.

Geography of Rain Forests

The geography of rain forests varies, depending upon location, and includes landforms, elevation, soil, and water resources.

Landforms

The terrain over which lowland forests grow features valleys, rolling hills, old river basins, and level areas. Montane forests develop in mountainous regions, as do cloud forests. Tropical mountains tend to be volcanic in origin, and their slopes are often gentle rather than steep and craggy (rugged and uneven).

Elevation

Rain forests grow at almost all elevations, from sea level to about 10,000 feet (3,000 meters). The greatest share of rain forested area exists at

elevations below 4,000 feet (1,200 meters), in what are known as lowland wet forests.

Soil

Rain forest soil tends to be red or yellow in color and low in nutrients because the vast number of plants quickly absorb its valuable minerals. Decaying vegetation continually enriches the topsoil, which is the most fertile soil near the surface. For this reason, tree roots are more likely to remain near the surface. In forests where the shade is dense, few smaller plants may grow and the topsoil layer is even richer. Where the ground is rocky and not much soil is present, trees may develop stiltlike projections from their trunks that help anchor them to the ground.

The presence of volcanoes increases the richness of soil in Indonesia and parts of Central and South America. Volcanic ash contains many minerals and adds nutrients to the soil.

Water resources

In tropical regions, rivers and streams are often the primary water resources. Daily rainfall not only helps maintain them, but can also cause them to flood.

Plant Life

Most forests contain a mixture of many different species of trees, and rain forests contain the most species. Both coniferous (cone-bearing) and nonconiferous evergreen trees exist within their boundaries. Exploration of most rain forests is challenging for humans so many of these species are yet to be named.

The trees and smaller plants in a rain forest grow to different heights, forming layers. The crowns of tall trees create a canopy, or roof, over the rest of the vegetation that averages 120 feet (37 meters) above the ground. The very tallest trees, called emergents, pop through the canopy like lonely towers, some as tall as 200 feet (61 meters). Trees help support one another because they grow so close together. Beneath the canopy grows at least one more layer of shorter, shade-tolerant trees, which cover heights of 30 to 65 feet (10 to 20 meters). This shorter layer is called the understory. The next layer, about 16 feet (3 meters) off the ground, is composed of tree seedlings, a few small shrubs, and a few flowering plants. The very lowest layer consists of small plants, like mosses, that live atop the soil.

Non-tree plants that grow in the rain forest are often either climbers, epiphytes (EPP-ih-fites), or parasites. Climbers have roots in the ground, but use hooklike tendrils to climb up the trunks and along the limbs of trees in order to reach the canopy where there is light. Epiphytes, or “air” plants, store water in their fleshy stems and leaves. They also grow on trees and other plants, especially in the canopy, but their roots are exposed to the air. These plants absorb the nutrients they need from rain and forest debris. Parasites attach themselves to other plants and trees, but they manage to do without light and take their nourishment from their host.

Rotten Flower

The Rafflesia (rah-FLEA-e-ah) plant of Malaysia is a parasite. Its seeds burrow beneath the bark of another plant and invade it with hairlike strands that absorb nutrients. Eventually a flower bud emerges, but the bud has no stem or leaves. About nine months later, this bud produces a spectacular bloom that measures as much as 3 feet (1 meter) in diameter and 37 pounds (81 kilograms). It is the largest known flower in the world. The Rafflesia is not content to be just a parasite with a big, unattractive flower. It also produces one of the worst fragrances imaginable, the smell of rotting meat. The Rafflesia’s goal is to attract flies with this fragrance in hopes that they will carry its pollen to a Rafflesia in the next forest.

Plant life within the rain forests includes not only trees but also algae (AL-jee), fungi (FUHN-ji), lichens (LY-kens) and green plants.

Algae, fungi, and lichens

Algae, fungi, and lichens do not fit neatly into either the plant or animal category.

Algae

Most algae are single-celled organisms, although quite a few are multicellular. Most algae have the ability to make their own food in a process called photosynthesis (foh-toh-SIHN-thuh-sis). During this process they use the energy from sunlight to change water and carbon dioxide into the sugars and starches they use for food. Other algae absorb nutrients from their surroundings.

Although most algae are water plants, green and blue-green algae do appear in the rain forest where they encrust the leaves of trees. This blocks the sunlight from the trees’ leaves, but the green-blue algae may aid the tree in obtaining nutrients, such as nitrogen, from the atmosphere.

Fungi

Unlike algae, fungi cannot make their own food by photosynthesis. Some fungi, like molds and mushrooms, obtain nutrients from dead or decaying organic matter (material derived from living organisms). They assist in the decomposition (breaking down) of this matter and in releasing the nutrients needed by plants back into the soil.

Other fungi are parasites. Fungi reproduce by means of spores, which are usually single cells that have the ability to grow into a new organism.

Fungi prefer moist, dim environments, and they thrive on the shadowy forest floor. Some, like the marasmius, grow directly on the litter of plant matter, while others protrude from the trunks of trees. Another type of fungi, the mycorrhizae, live in the soil and surround the roots of most rain forest trees. They absorb energy from the tree and help the tree’s roots absorb nutrients from the soil.

Lichens

Lichens are actually combinations of algae and fungi that live in cooperation. Fungi surround algae cells, and the algae obtain food for themselves and the fungi by means of photosynthesis. It is not known if fungi aid algal organisms, but it is believed that fungi may provide moisture for the algae.

Lichens often appear on rocks and other bare woodland surfaces. Some grow on the leaves of lowland trees, while others favor the cooler cloud forests and dangle from the limbs of trees. Lichens are common in all types of forests and seem able to survive most climatic conditions.

Green plants other than trees

Most green plants need several basic things to grow: sunlight, air, water, warmth, and nutrients. In the rain forest, water and warmth are abundant. However, nutrients such as nitrogen, phosphorus, and potassium, which are typically obtained from the soil, may not be in large supply. Light can be scarce because the thick forest canopy obscures the forest floor, and may block sunlight. The lack of seasons means that the canopy is in full leaf all year long. For this reason, most rain forest plants grow in the canopy of the forest. Those that do grow on the ground often have very large leaves that provide more surface area to be exposed to the scarce amount of light.

Common rain forest green plants

Common rain forest plants include rattans, pitcher plants, ferns, African violets, nasturtiums, Spanish mosses, orchids, lianas, urn plants, hibiscus shrubs, and bamboo.

Liana Lianas are climbers found in rain forests throughout the world. Their roots can be large and tough, but they do not develop a thick trunk. Instead, they depend entirely on trees for support. Once they reach the canopy, they drape themselves among the branches and develop leaves, branches, flowers, and fruits. Often they send out “feeding,” or aerial (AIR-ee-yuhl), roots that dangle in midair and absorb nutrients.

A common liana is the strangler fig, which begins as an epiphyte that sends long roots down to the ground. These roots grow branches that

Chocoholic Heaven

In the rain forests of Central and South America grows the cocoa, or cacao, tree. The seeds of this delightful tree produce chocolate. Initially, the roasted seeds were used by the Aztecs to make a hot drink flavored with vanilla and spices. In 1502, Italian explorer Christopher Columbus (1451–1506) brought the cocoa “beans” back to Spain, where the same drink was made but with sugar. Over the next 100 years, the use of cocoa spread to other parts of Europe and, by 1657, solid chocolate had been developed in France. Around 1700, the English improved hot chocolate by adding milk, and by 1850, manufacturing processes made sweet eating-chocolate possible. By 1876, its popularity had spread throughout the world.

Cocoa trees are raised on farms in Central and South America and portions of western Africa. In 1977, 1,653,000 tons (1,500,000 metric tons) of cocoa seeds were produced, and 20 percent of all the exports went to the United States. However, Americans consume only about 10 pounds (4.5 kilograms) of chocolate per person annually. The largest consumers are the Swiss, who eat 21 pounds (9.5 kilograms) per person each year.

Although the names are sometimes confused, the cocoa tree is not the source of the drug cocaine. Cocaine comes from the coca shrub, an unrelated plant.

surround the host tree, blocking the light. Eventually, the host dies and decays, leaving a hollow ring of stranglers.

Urn plant Urn plants are epiphytes found in Central and South America that belong to the pineapple family. The plant’s overlapping leaves form an urn, or cup, which collects rainwater and any dead plant matter that falls into it. Little hairs on the leaf surface absorb the water and dissolved minerals. Urn plants provide homes for many aquatic (water) insects and even frogs.

Hibiscus Hibiscus shrubs grow on the ground around the edges of the forest where they can obtain light. In Africa, they quickly attain heights of up to 7 feet (2 meters). Their large, colorful flowers are bell shaped and may be scarlet, pink, yellow, or white.

Bamboo Bamboo is a woody grass that can grow as tall as a tree. Dense forests of bamboo are found in Asia and Central Africa where plants may reach 130 feet (40 meters) in height. Bamboo tends to grow in thick, tightly packed clumps. Flowering occurs several years later, after which the plant dies. There are 480 species of bamboo. Its uses vary from food to instrument to paper.

Growing season

It is always growing season in the tropical rain forest. At any given time, at least one species will be flowering.

Reproduction

Most green plants are seed plants, and most seed plants are flowering plants that reproduce by means of pollination. Pollination involves the transport of pollen from the stamen, the male part of the flower, to the pistil, the female part of the flower where seeds develop, by visiting animals or the wind. The seed’s hard outer covering protects it while it waits for moisture and light to stimulate its growth.

Instead of pollination, some plants reproduce by means of rhizomes—long, rootlike stems that spread out below ground. These stems develop their own root systems and send up sprouts that develop into new plants.

Rain forest trees

Most trees have a single strong stem, or trunk. This single trunk gives them an advantage over smaller woody plants in that most of their growth is directed upward. Some large rain forest trees develop buttresses, winglike thickenings of the lower trunk that give tall trees extra support.

As a tree grows, its trunk is thickened with a new layer, or ring, of conducting tissues that carry water and nutrients from the roots to the branches. As the tree ages, the tissues from the center outward become hardened to produce a sturdy core. In cooler climates, the rings are formed seasonally and, when a tree is cut down, its age can be determined by how many rings are present. In the rain forest there are no seasons, so rings do not form regularly and cannot be used to accurately estimate a tree’s age. Other methods are used to determine the age of rain forest trees, such as measuring the increase in the tree’s circumference during a year and dividing that number into its total girth (size). Based on these calculations, one species in Malaysia may be 1,000 years old, a baby compared to the 4,900-year-old bristlecone pine of North America, but unusually old for the rain forest, where most trees only live 100 to 300 years.

Rain forest trees seldom exceed 200 feet (61 meters) in height, although the tualang of Malaysia has been recorded at 260 feet (80 meters). It is a common misconception that the world’s tallest trees grow in the rain forests. The tallest trees grow in drier, more temperate climates.

The leaves of rain forest trees are often waxy and develop a “drip tip;” a long, narrow point that allows rain to run off easily.

Common rain forest trees

Common rain forest trees include black ebony, cinchona, mahogany, and mango.

Black ebony Found in the rain forest of Africa, the black ebony tree is almost white in color, but its heartwood is black and extremely hard. Valued for its heaviness, color, and durability, ebony heartwood is considered a precious wood. It has been commonly used to make the black chord keys on a piano.

Cinchona The cinchona (sing-KOH-nah) is native to Central and South America where it is found in lower montane rain forests. Its flowers grow in white, pink, and yellow clusters and its bark is an important source of several medicines, including quinine (KWY-nine), a treatment for malaria. During the 1800s, cinchona seeds were brought to Java in Indonesia, where the trees are still raised commercially.

Mahogany The term mahogany is applied to almost 200 species of trees with reddish-brown wood, winged seeds, and small, greenish-yellow flowers. The first trees given the name are native to the West Indies, but the most commercially important mahoganies come from Central and South America. They are used in fine furniture and paneling. African and Philippine mahogany are also economically important.

Mango The mango tree was originally discovered in East India. In its wild state, it produces a fibrous fruit that tastes like turpentine. In some species, this fruit is poisonous. Cultivated trees produce a delicious fruit that is enjoyed throughout the world. In the fifth century BC the mango was brought to Malaysia and eastern Asia. In India, the mango tree is sacred, believed to be a symbol of love and having the potential to grant wishes. The tree can reach heights of about 90 feet (27 meters) and is popular for its dense shade.

Growing season

Trees are woody perennial plants, which means they live more than one year, or growing season. When temperatures are warm year-round and rainfall is constant, as they are in the rain forest, trees become evergreen and grow almost continuously. Some rain forest trees shed their leaves periodically for a short time; however, this shedding is not simultaneous, even among trees of the same species.

Many rain forest trees do not bear fruit every year and thus do not regenerate readily. Seeds that lie on the forest floor may remain dormant (inactive) for many years. Those that sprout grow very slowly after the nutrients stored in the seeds are used up. If a tree falls and creates a gap in the canopy allowing sunlight to enter, these seedlings make up for lost time. They grow quickly toward the light and soon the gap is closed again.

Reproduction

In general, trees are divided into two groups according to how they bear their seeds. Gymnosperms produce seeds inside cones. Most conifers, like the pine, are gymnosperms. Angiosperms have flowers and produce their seeds inside fruits. Broad-leaved trees, such as maples, are usually angiosperms. Some species of gymnosperms are found in rain forests, but most rain forest trees are angiosperms.

The seedlings of some rain forest trees do not develop large amounts of chlorophyll, the substance in leaves that gives them their green color, until they reach light in the canopy. The leaves of these young trees are often red, blue, purple, or white instead of green.

Endangered species

Vast areas of rain forest have been destroyed by uncontrolled logging and clearing of the land for farms. From 2000 to 2005, tens of thousands of miles of rain forest in Brazil were lost due to deforestation. In more mountainous regions, such as Papua New Guinea, the land is less useful for farming and huge tracts of rain forest still remain untouched.

Many individual plants are threatened as the forest is destroyed. The African violet, for example, which is commonly cultivated as a house plant, is found in only a few forests in Tanzania, where it is rapidly disappearing.

Animal Life

Animal life in the rain forest is as diverse as its plant life because the warm temperatures and plentiful moisture aid survival. Most animals live in the trees, especially high in the canopy.

Microorganisms

Microorganisms, like their name suggests, can not be seen without the aid of a microscope. Bacteria are microorganisms that are always present in forest soil. They help decompose dead plant and animal matter. They grow quickly in the warm, humid rain forest environment where they feed on the leaves, twigs, and other matter that falls from the canopy.

The Web of Life: Biotic Potential

The highest rate of reproduction under ideal conditions is a population’s biotic potential. For most creatures, this potential is enormous. A single bacterium, for example, could set off a chain reaction of births that would cover our planet within thirty-six days.

What keeps bacteria, as well as mosquitoes, frogs, and alligators reaching their full biotic potential? The answer is that, while creatures are determined to reproduce, life is not easy. Each life form is opposed by limiting factors that keep population growth in check. Cold temperatures, for example, kill mosquitoes. A shortage of mosquitoes starves frogs. A shortage of frogs keeps alligators hungry, preventing them from reproducing more quickly and taking over the world.

Invertebrates

Animals without backbones are called invertebrates. They include simple animals such as insects and worms, and more complex animals such as the click beetle or the trapdoor spider. Certain groups of invertebrates, like mosquitoes, must spend part of their lives in water. In general, these types are not found in the trees, but in streams or in pools of rainwater. The humid rain forest is an ideal environment for many soft-bodied invertebrates, such as leeches, because there is little danger of drying out.

Common rain forest invertebrates

In addition to bacteria, invertebrates remain the least known variety of life in the rain forest. Among those that have been identified are the Hercules beetle, the forest termite, the orchid bee, the Queen Alexandra’s birdwing butterfly, the postman butterfly, the blue hunting wasp and the army ant.

Postman butterfly The postman butterfly lives in jungles of Central America. In its larval state as a spiny caterpillar, it is a voracious eater with a preference for the passionflower vine. The adult butterfly feeds on this vine’s protein-rich pollen and nectar. The added protein gives it a longer lifespan than most butterflies, usually from six to nine months. The passionflower is a highly poisonous plant, so female butterflies lay their eggs on its youngest leaves, which contain less poison. As the larvae grow, they gradually absorb some of the poison and become immune to it.

The Web of Life: How Ants Help to Make Rain

Seventy-five percent of the rain that falls on the rain forests is recycled. It evaporates and creates clouds that protect the forest from too much sun. Many creatures help in this process. For example, the forests of the Amazon are home to vast armies of ants. Ants produce formic acid, which they use for defense and as a means of communication. They spray approximately 200,000 tons (181,400 metric tons) of formic acid into the air each year. This formic acid makes the rain that falls in the area slightly acidic and promotes the decay of dead wood. As the wood decays, bacteria are released into the atmosphere, where ice crystals tend to form around them. The ice crystals fall as rain, and the cycle continues.

Blue hunting wasp The blue hunting wasp prefers dining on crickets, which it hunts by flying low over the forest floor. It grips a victim in its powerful jaws and then paralyzes it with its stinger. Female wasps drag the paralyzed victim into a burrow and then lay their eggs on it so their larvae have food when they hatch.

Army ant Army ants are some of the most feared residents of the rain forest because they travel in huge colonies of up to 20 million individuals. The army’s number demands that food be plentiful. The army usually empties an area of insects, small lizards, and snakes, leaving them no choice but to continue moving. They take shelter at night by linking themselves together with their strong legs beneath the fallen leaves and trees. When they are on the march, worker ants carry any developing larvae with them.

Food

Many invertebrates eat plants or decaying animal matter. The larvae of insects, such as caterpillars, are the primary leaf eaters. Weevils drill holes and lay their eggs in nuts, which their larvae use for food. Bees gather pollen and

nectar from flowers, as do butterflies and moths. The arachnids (spiders), which are carnivores (meat eaters), prey on insects and sometimes, if the spiders are big enough, small lizards, mice, and birds.

Reproduction

Most invertebrates have a four-part life cycle. The first stage of this cycle is spent as an egg. The eggshell is usually tough and resistant to long dry spells in tropical climates. After a rain, and during a period of plant growth, the egg hatches. The second stage is the larva, which may be divided into several stages between which there is a shedding of the outer skin as the larva increases in size. Larvae often spend their stage below ground where it is cooler and moister than on the surface. The pupal, or third stage, is spent hibernating within a casing, like a cocoon. In the fourth and final stage, the animal emerges from this casing as an adult.

Amphibians

Amphibians are vertebrates (animals with a backbone) that usually spend part, if not most, of their lives in water. Frogs, toads, and salamanders are all amphibians. They live in significant numbers in rain forests where humid conditions are ideal. Amphibians are cold-blooded, which means their bodies are about the same temperature as their environment. In the rain forest they can be active year-round because the temperature is always warm.

Amphibians breathe through their skin, and only moist skin can absorb oxygen so they must usually remain close to a water source. Mating, egg-laying, and young-adulthood all take place in ponds, lakes, or pools of rainwater. When they mature, amphibians leave the pools for dry land where they feed on both plants and insects.

Common rain forest amphibians

Amphibians commonly found in rain forests include tree frogs and poison arrow frogs.

Tree frog Eighty percent of frogs and toads live in tropical forests. Some, such as the fringe limb tree frog, may leap out of a tree to escape a predator. Webs of skin between their limbs act like parachutes, enabling them to glide from one branch to another. Other species of tree frogs have suction pads on their toes that secrete a sticky mucus, enabling the frog to cling to tree trunks and branches.

Poison arrow frog Poison arrow frogs are usually brightly colored. This color warns potential predators that to bite the frog may mean death. One ounce of poison from the kokai frog can kill up to 100,000 average size humans. These frogs, abundant in South America, are used by the local people, who tip their arrows and darts in the poison (hence the frogs’ name).

Food

Most adult amphibians are carnivorous, feeding on insects, slugs, and worms. Salamanders that live in the water suck their prey into their mouths. Those that live on land have long, sticky tongues to capture food. Salamander larvae are mostly herbivorous, feeding on vegetation. Frogs and toads feed on algae, plants, and insects such as mosquitoes.

Reproduction

Mating and egg-laying for amphibians must take place in water because male sperm are deposited in the water and must be able to swim to the eggs in order to penetrate them. Some amphibians lay their eggs in the cups of plants where water has collected and where insect larvae may grow. As the young develop into larvae and young adults, they often have gills for breathing. They, too, require a watery habitat.

Reptiles

Reptiles that live in rain forests include snakes and lizards. Since a reptile’s body temperature changes with the temperature of the surrounding air, the warm, humid rain forest is a comfortable environment for them.

Many rain forest reptiles are capable of camouflage (KAH-mahflahj), or protective coloration. Their skins are often patterned or colored to resemble the forest background in which they live, and they may be able to alter their coloration to a darker or lighter shade. Many reptiles living in the forest canopy have a prehensile (grasping) tail to help them climb and may prevent falls. Rain forest reptiles may have grasping claws to ensure a firm, steady hold as they climb through the trees.

Common rain forest reptiles

Common rain forest snakes include the vine snake of West Africa, the bushmaster and fer-de-lance of Central and South America, the gaboon viper of Asia, and many tree snakes. Lizards include the Jesus Christ lizard of Central America, the crested water dragon of Asia, Parson’s chameleon of Africa, and the Komodo dragon of Indonesia.

Chameleon The chameleon (kuh-MEEL-yuhn) lizard is an expert at camouflage. A resident of the canopy, it can change its coloration to resemble that of the leaves, and it may even tremble slightly to mimic leaves swaying in a breeze. Its feet and tail are perfect for grabbing hold of tree limbs, and its long, sticky tongue flicks out with amazing speed to catch the insects that make up its diet.

Tree snake Many species of tree snakes are found in rain forests. The emerald tree boa of the Amazon is not poisonous, and kills its prey with by squeezing it. Pythons, anacondas, and cobras are found in the rain forest. Pythons can be found in Africa and Australia, cobras in Africa and Asia, and the anaconda in South America.

Komodo dragon The Komodo dragon, the world’s largest lizard, is found in Indonesia, especially on Komodo Island for which it is named. Komodo dragons can measure up to 10 feet (3 meters) in length and weigh up to 366 pounds (166 kilograms). Komodo dragons are carnivores and eat animals as large as buffalo or as small as geckos and other insects. They have long, sharp claws and jagged teeth that enable them to tear meat from their prey. In 1992, komodo dragons hatched at the Smithsonian Zoo, the first of their kind to ever have been bred outside of Indonesia.

Food

A lizard’s diet varies, depending upon the species. Some have long tongues with sticky tips for catching insects, while others eat small mammals and birds. The water they need is usually obtained from the food they eat.

All snakes are carnivores, and one good meal will last them for days or weeks. Some snakes kill their prey with venom (poison) injected through their fangs.

Reproduction

Most reptiles lay eggs. Some females remain with the eggs, others bury them in a hole and abandon them leaving the young to hatch by themselves. Snakes that live in the canopy often bear live young. They produce fewer babies, but the babies, being mobile, have a better chance of survival.

Green Mansions

The South American rain forest provided the setting for Green Mansions, a novel by British author W. H. Hudson (1841–1922) that was written in 1904. It is a fantasy love story about Rima, a strange half-bird, half-human character who lives in the forest and cannot leave it. A statue of Rima was erected in 1925 in the bird sanctuary at Hyde Park in London, England.

Birds

All rain forests have large bird populations. Most do not need the protection of camouflage, having only to compete with bats, and their feathers are usually brilliantly colored. Their songs vary from the scream of the eagle to the haunting warble of many smaller birds. Bower birds and pittas seem to be able to “throw” their voices like ventriloquists.

Rain forest birds have developed short, broad wings that do not require much room for flying because the vegetation is so dense. Some species, such as toucans and parrots, have feet adapted to climbing.

Common rain forest birds

Common birds of the rain forests include toucans, hummingbirds, birds of paradise, jacamars, eagles, parrots, and junglefowl.

Harpy eagle Harpy eagles live high in the forest canopies of Central and South America, often sitting in one of the emergent trees where their sharp eyes can spot prey. Harpies do not soar high above, but move from tree to tree in short flights. Their large nests are built of sticks, leaves, and fur about 165 feet (50 meters) above the ground. Females produce two eggs. Harpies like to catch monkeys or sloths in their huge talons, and, if their victim attempts to cling to a tree, they are strong enough to wrench the victim free.

Parrot Parrots are brightly colored birds with a loud, harsh call. There are 328 species of parrots, including the commonly known parakeets, macaws, and cockatoos. They tend to be social and roost in large groups. Their feet are strong enough to make it possible for them to hang upside down from a branch for long periods. Their nests are usually in holes in trees, where the female sits on the eggs, and the male brings her food. Preferring to eat seeds, parrots use their tongues to position a seed at the front of the strong, hooked beak and then crack the seed apart. Parrots, well know for their ability to mimic humans, are popular and desirable pets.

Junglefowl The junglefowl of Asia is the ancestor of the chicken and, as such, has affected human life more than any other bird. Male junglefowl crow like roosters and have a red comb. In the wild, they are very aggressive; much of this behavior has been bred out of the domesticated species over the years. They live primarily on the forest floor where they feed on seeds, fruits, berries, and insects. They are good runners, but their flight is weak.

Food

Rain forest birds may fly considerable distances in search of trees bearing fruit. Different birds seek food in different layers of the forest. Parrots, for example, hunt for seeds in the canopy and insects along the trunks of the trees, while pittas dig around on the ground for snails and ants.

Reproduction

Birds reproduce by laying eggs, for which many species build a nest. Some, such as the macaw, prefer to use a hole in a tree. Females usually sit on the eggs until the young birds hatch. The female hornbill of Southeast Asia walls herself into a hole with mud and other materials and the male feeds her until the young can leave the nest. Both parents of most species usually feed their young until they are able to fly. Some young birds, such as the hoatzin of the Amazon region, are uniquely adapted to life in the forest. The hoatzin chicks have two claws on each wing, enabling them to climb through the branches.

Mammals

Mammals of all kinds live in the rain forest, from the monkeys that swing from the tops of its trees to the shrews that scamper about the jungle floor.

Common rain forest mammals

Rain forest mammals include monkeys, antelopes, coatis, bats, sloths, okapis, gorillas, and jaguars.

Bat Bats are the only mammals truly capable of flight, which they do primarily at night. During the day, they sleep hanging upside-down from branches or holes in trees. Some species are very social and roost in groups of 100 or more. At night they leave their roosts to seek food. A rain forest bat’s diet is either insects or flower nectar and fruits. Many trees are dependent upon them as an aid in pollination.

The God of the Air

The quetzal, or resplendent trogon, of the mountain jungles of Central America has some of the most colorful plumage of any bird. To the Mayas and Aztecs, the quetzal’s emerald and crimson feathers symbolized spring vegetation. They used its tail feathers in religious ceremonies and worshiped the bird as a god of the air. The beautiful quetzal is the national emblem of Guatemala, and its name is given to a unit of Guatemalan currency.

Sloth Sloths are slow-moving creatures with large claws that spend their lives hanging upside-down from tree limbs in Central and South America. Adults are only about 2 feet (0.6 meters) long, and the claws by which they grip the trees measure about 3 inches (8 centimeters). Sloths are so well adapted to their life upside-down that even their hair grows that way, from stomach to spine. They are herbivores that almost never leave the trees because, on the ground, a sloth cannot stand or walk but rather drags itself around with its claws.

Okapi The okapi, a short-necked relative of the giraffe that lives in the rain forest of eastern Congo, was not discovered by European explorers until 1901. It feeds on understory vegetation, such as shrubs and leaves. The coat is purplish brown, with black and white stripes on the upper legs and buttocks. Okapis are unusual in that females are larger than males.

Gorilla Gorillas are found only in Africa, where there are three species: the western lowland gorilla, the mountain gorilla, and the eastern lowland gorilla. These types vary slightly in physical characteristics, such as color.

The gorilla is the world’s largest living primate (group of animals including apes, monkeys, and humans). Males may be as tall as 6 feet (1.8 meters) and weigh between 300 and 400 pounds (135 and 180 kilograms). Gorillas live in groups and rarely change locations if they can help it. They spend most of their day, apart from a midday rest period, foraging for food, primarily nuts, berries, fruits, and leaves.

World’s Smallest Mammal

The world’s smallest mammal is only 1 inch (2.5 centimeters) long, about the size of a bumblebee. It was first catalogued by researchers in 1974. It may have been overlooked until then because it only comes out at night and might have been mistaken for an extremely large mosquito. This little mammal is the Kitti’s hog-nosed bat, and it lives in the rain forests of Thailand.

Jaguar The largest cat in the western hemisphere, jaguars are found mostly in South America. A male jaguar may be 6 feet (1.8 meters) in length with a 2-foot (0.6-meter) -long tail, and may weigh more than 300 pounds (135 kilograms). It has a tan coat and is spotted like a leopard, though some are completely black or white. Jaguars feed on both small and large animals. They hunt mostly on the ground, but they are agile (skilled) climbers and swimmers.

Food

Small mammals, such as the fawn-footed melomys (a type of rodent), often eat plants and insects. Herbivores (plant-eaters), including the agouti, the paca, and the royal antelope, feed on leaf buds and fruit. Cats, such as the palm civet, the ocelot, and the servaline genet, are carnivores (meat-eaters). Many mammals, such as the orangutan, are omnivores, which means they eat both plant and animal foods.

Reproduction

The young of mammals develop inside the mother’s body, where they are protected from predators. Mammals produce milk to feed their young and must remain nearby until the young can survive on their own.

Endangered species

The list of endangered rain forest animals is long. Many species of parrots are endangered, especially in Central and South America, because they are sought by animal dealers to sell as pets or because their habitat is disappearing. An example is the Spix’s macaw, found in Brazil. In 1999, only one bird remained alive in the wild. Concentrated efforts to bring the bird out of near extinction resulted in sixty birds living in captivity. Reintroducing them to the wild has been difficult. Biologists are attempting to send females into the wild in hopes that they will mate with the lone male.

Orangutans and gorillas are in danger because they require deep forest cover and their habitat is rapidly disappearing. For some, their only hope of preservation seems to be zoos and wildlife sanctuaries. Many rain forest cats are also endangered because they have been hunted extensively for their skins. Although many are now protected, their numbers are so low there may not be enough animals left for successful breeding.

Only five species of rhinoceros remain in the world. They are protected, but remain threatened by poachers who kill them for their horns, and by the loss of their habitat. Rhinos live in Africa, India, and Southeast Asia. Although their senses of smell and hearing are well developed, they can not see very well, making them susceptible to attack from both humans and forest predators.

Human Life

Humans are creatures of the forest. Until they learned to hunt, humans gathered their food and made their dwellings among the trees of the forests.

Impact of the rain forest on human life

Forests have an important impact on the environment as a whole. From the earliest times, forests have provided humans with food and shelter, a place to hide from predators, and many useful products.

Rain Forest Cousins

Chimpanzees are great apes, the closest living relatives to the human species. They resemble humans in some important ways, including their use of tools. Some chimp populations in western Africa use stone and wooden hammers to break open nuts. In eastern Africa, chimps have been observed to stick plant stems into termite nests to drive the termites out so they can eat them, and during a heavy rain they use leafy tree branches as umbrellas.

Environmental cycles

Trees, soil, animals, and other plants all interact to create a balance in the environment from which humans benefit. This balance is maintained in what can be described as cycles.

The oxygen cycle Plants and animals take in oxygen from the air and use it for their life processes. This oxygen must be replaced, or life on Earth could not continue. Animals breathe in (inhale) oxygen and breathe out (exhale) carbon dioxide. Trees convert this carbon dioxide into oxygen during photosynthesis, releasing the oxygen into the atmosphere through their leaves.

The carbon cycle Carbon dioxide is necessary to life, although too much is harmful. During photosynthesis, trees pull carbon dioxide from the air. This helps maintain the oxygen/carbon dioxide balance in the atmosphere. When trees die, the carbon in their tissues is returned to the soil. Decaying trees become part of Earth’s crust, and after millions of years, this carbon is converted into oil and natural gas.

The water cycle The root systems and fallen leaves of trees help build an absorbent covering on the forest floor that allows rain water to trickle down into the soil to feed streams and groundwater. In this way, forests help conserve water and protect the soil from erosion caused by heavy rain. When forests are cut down, the soil washes away and flooding is more common. For example, heavy rainfall in Indonesia has caused severe flooding, in part due to tree removal. Trees take up some of this rain water through their roots and use it for their own life processes. Extra moisture is released through their leaves back into the atmosphere, where it helps to form clouds.

The nutrient cycle Trees get the mineral nutrients they need from the soil. Dissolved minerals are absorbed from the soil by the tree’s roots and are sent upward throughout the tree. These mineral nutrients are used by the tree much like humans take vitamins. When the tree dies, these nutrients, which are still contained within parts of the tree, decompose. They are then returned to the soil making them available for other plants and animals.

Food

Forests are the home of game animals, such as birds, that provide meat for hunters and their families. Forests also supply fruits, nuts, seeds, and berries, as well as vegetation for livestock. Vanilla, for example, is made from the seed pod of a type of orchid found in Central and South American rain forests; nutmeg and cloves come from Asian rain forests; coffee beans are native to Africa and are products of Central America along with cocoa beans; and starfruits grow in Asia. It is estimated that rain forests contain more than 3,000 species of edible fruits and vegetables, and only about 200 of these have been cultivated for commercial use. With correct management these species might yet provide more food varieties for both humans and animals.

Shelter

During prehistoric times, humans lived in the forest because it offered protection. Today trees can provide building materials. Trunks are cut into planks or used as poles, while fronds (branches) and grasses can be cut for thatch and used to make huts or roofs for wooden structures.

Economic values

Forests are important to the world economy. Many products used commercially, such as wood, medicines, tannins, dyes, oils, and resins (sap) are obtained from forests. Forest land is also important to the farm and tourist industries.

Wood

Trees produce one of two general types of wood, hardwood or softwood, based on the tree’s cell wall structure. Hardwoods are usually produced by angiosperms, such as the mahogany tree, while most coniferous trees, such as pines, produce softwoods. These names can be confusing because some softwood trees, such as the yew, produce woods that are harder than many hardwoods. Some hardwoods, such as balsa, are softer than most softwoods.

Coffee—The World’s Most Valuable Agricultural Product

In the mid-1990s, imports of coffee beans to the United States totaled $1.5 billion each year. The United States is the world’s largest importer, and the average American drinks about 27 gallons (102 liters) of coffee annually.

Coffee trees grow in montane forests, and coffee beans are the roasted seeds of the tree. The birthplace of coffee was probably Ethiopia, the tree’s native environment. Its use was first developed by the Arabs, and it did not arrive in Europe until the sixteenth century where it was introduced as a medical potion. Coffee became popular as a beverage around 1652. Coffee plantations were soon established in Indonesia, the West Indies, and Brazil, and coffee cultivation became important to colonial economies. Latin America and Africa produce most of the world’s coffee; Central and South America grow about 60 percent of the world’s total production.

Wood is used for fuel, building structures, and manufacturing other products, such as furniture and paper. Wood used for general construction is usually softwood. In order to conserve trees and reduce costs, some manufacturers have created engineered wood composed of particles of several types of wood combined with strong glues and preservatives. Engineered woods are very strong and can be used for many construction needs.

In an effort to preserve the natural forests, plantations are developed to supply the world’s demands for wood. India, South America, and Africa combined have 102,000 square miles (264,178 square kilometers) of tree plantations.

Farmland

Although rain forest land is poor for farming, more and more of it is being cleared for that purpose. It supports crops for a few years, and then it is used for cattle pasture. When its nutrients are completely exhausted it is abandoned.

Medicines

Since the earliest times, plants have been used for their healing properties. It is estimated that at least 70 percent of cancer fighting plants are tropical plants from the rain forest. Quinine, from the cinchona tree, is used to fight malaria.

Deadly Traveler on the Kinshasa Highway

The Kinshasa Highway crosses central Africa, linking remote areas to airports in the large cities of Nairobi and Mombasa, both in Kenya. Any traveler starting from deep inside the rain forest who reaches one of those airports is within 24 hours of every other place on Earth. During the 1970s one traveler made such a journey, a journey of deadly consequence.

The traveler was HIV, the human immunodeficiency virus, and by 2007, only twenty-five years after its emergence from the rain forest, it had infected 40 million people worldwide. Already 25 million people have died of AIDS (acquired immune deficiency syndrome), which appears to be caused by HIV.

For millennia, potentially deadly bacteria and viruses have remained undisturbed in the rain forests. If humans caught them, villages were so remote and travel so slow that infected people seldom lived long enough to reach large populated areas where the disease could spread unchecked. As humans penetrate farther into the rain forest and destroy the natural balance that often keeps disease carriers under control, more and more problems are being created. The latest cause for concern is the hemorrhagic fever viruses, such as Ebola zaire, another rain forest resident, which is even more deadly than HIV.

Tannins, dyes, oils, and resins

Tannins are chemical substances found in the bark, roots, seeds, and leaves of many plants. It is used to cure leather, making it soft and supple. Dyes used to color fabrics can be obtained from the bark or leaves of such trees as the brazilwood. Palm oil and coconut oil are used as cooking ingredients. Resins, or saps, are used in paints and other products. Chicle is a resin from the sapodilla tree used in chewing gum, and natural rubber is made from the resin of the South American rubber tree.

Tourism

Rain forests have become popular with tourists who are interested in hunting, nature study, and environmental issues (ecotourism). Some tropical countries have found it economically desirable to set aside large tracts of forest for tourism.

Impact of human life on the rain forest

While forests have had a positive effect on human life, human life has had a mostly negative impact on forests. Nearly 60,000 square miles (155,399 square kilometers) of forest are cleared each year. Most of the forest loss has occurred in developing nations where wood is used for fuel and trees are cleared for farming. A large number of trees are also lost each year to commercial use.

Rain Forest Explorers

When Europeans first encountered the rain forest, they saw it from a position at its edge, where light could penetrate and foliage ran rampant. The forest soon gained a reputation for being impenetrable, and the first men who ventured into it had remarkable courage. Many were seekers of knowledge about the world; others had a hunger for riches that they believed they would find in the jungle.

At first, valuable goods were the primary target. The Portuguese penetrated Africa by means of its rivers but gained little knowledge of the interior. Few who entered it, such as Portuguese explorer Vallarte in 1448, came back alive. The first European to explore the rain forests of the Amazon in South America was Francisco de Orellana who went in search of cinnamon trees and gold in 1541.

In the 1700s, scientific curiosity became the primary motive for exploration. Between 1799 and 1803, Alexander Baron von Humboldt and Aime Bonpland explored thousands of miles of South America in order to study plant and animal life. During the nineteenth century, journalist Henry Morton Stanley (1841–1904) made a dangerous voyage the length of the Congo River in Africa. Prince Maximilian of Wied-Neuwied, Henry Walter Bates, Alfred Russel Wallace, Jules Crevaux, and, in the twentieth century, Theodore Roosevelt (1858–1919), Percy Fawcett, and Michael Rockefeller also undertook journeys into unexplored regions.

Use of plants and animals

Rain forests are disappearing at alarming rates each year, especially the montane forests. Much forestland is being lost as populations grow and want the land for farms and cattle pasture. Slash and burn agriculture is a routine procedure in which trees are cut and burned. When the land will no longer support crops, it is abandoned and additional forest is cut down somewhere else. As a result, many animals and plants are permanently losing their habitats.

Our ability to harvest trees for wood is greater than the forest’s ability to regenerate. Mechanical harvesting with huge machines makes clear-cutting (cutting down every tree in an area) cheaper and more efficient than selecting only certain trees for harvesting. Replanting may not be done, or a fast-growing species may be replanted rather than the original species. The original species may never grow back. Clear-cutting endangers wildlife by destroying natural habitats.

Quality of the environment

Destruction of the forests does not mean just loss of their beauty and the products they provide. Water quality suffers because the trees are gone and rain no longer seeps into the soil. Instead, it runs off and underground water reserves are not

replaced. Topsoil is eroded away and often ends up in streams and rivers. If the quantity of soil is large enough, fish may die.

Air quality is also reduced by the destruction of forests. Trees not only put oxygen back into the air, but soot and dust floating in the air often collect on their leaves and are washed to the ground when it rains. When the trees are cut down, the dust and soot remain in the air as air pollution.

With the popularity of the automobile, carbon dioxide and other undesirable gases have built up in the atmosphere. Most scientists believe these gases are helping raise the temperature of Earth’s climate (the greenhouse effect). Forests help remove carbon dioxide from the air, so cutting them down may be a factor in global warming. If Earth grows warmer, many species of plants and animals could become extinct.

Forest management

Most rain forests grow in developing countries that need forest resources for economic reasons. Since 1945, more than 50 percent of the world’s rain forests have been cut down and cleared away. Some countries have realized that they must use their resources wisely, and conservation efforts are under way. Malaysia and Uganda, for example, are making better use of trees that were formerly wasted, and replanting programs have begun in Gabon and Zambia.

Native peoples

Native people have been found in all the major rain forests of the world. They include the Yanomami of South America, the Asanti and Bambuti of Africa, the Andaman of Asia, the Aeta of the Phillipines, the Penan of Borneo, and the Aborigines of Australia.

In general, forest dwellers are hunter-gatherers who make few changes to the forest environment. Changes other people are making may destroy their way of life.

Yanomami

The Yanomami tribe, comprised of four smaller tribes, are scattered across Brazil and Venezuela. Only about 20,000 of them remain, as their population has decreased by over 10 percent in the last twenty years. The Yanomami live in villages as few as 40 residents to as many as 300 people. Trade and marriage keep the villages in contact with one another; sometimes peacefully and other times not. They seldom leave the forest, as it provides them with all they need to survive. Huts are built from timber and vine and food is either grown or hunted.

Asante

The Asante (sometimes referred to as Ashanti) of Africa make their home in Togo and the Ivory Coast. Like many native tribes, they began as forest dwellers. Loss of their home due to the clearing of the forest has caused some to move to nearby towns. Farming is their main livelihood. They export plantains, bananas, yams, and other staples to the local market.

Although mostly a peaceful tribe, the Asante have their share of war and strife. In the seventeenth century, firearm trade caused a power struggle in which the Asante prevailed. Then in the nineteenth century, they fought the British seeking an independent government from the Republic of Ghana. This battle was lost, but the Asante were allowed to live in peace, and they now number over 600,000 people.

Andaman

The Andaman tribe is the only tribe of natives that never learned to make fire. They waited for fire to naturally occur, such as lightning fires, and then were careful to preserve the fire as long as possible.

Located on the Andaman and Nicobar islands in the Bay of Bengal, they survive by hunting, and their diet consists of no plants or vegetables. As islanders, they seek out iron from nearby shipwrecks and use it to make their weapons.

The Food Web

The transfer of energy from organism to organism forms a series called a food chain. All the possible feeding relationships that exist in a biome make up its food web. In the rain forest, as elsewhere, the food web consists of producers, consumers, and decomposers. An analysis of the food web shows how energy is transferred within the biome.

Green plants are the primary producers in the forest. They produce organic materials from inorganic chemicals and outside sources of energy, primarily the Sun. Trees and other plants turn energy into plant matter.

Animals are consumers. Plant-eating animals, such as certain insects and mice, are the primary consumers in the rain forest food web. Secondary consumers, such as anteaters, eat the plant-eaters. Tertiary consumers are the predators, like owls and leopards. Some, such as orangutans and humans, are omnivores.

Decomposers feed on dead organic matter and include fungi and animals like the vulture. In the moist rain forest, bacteria aid decomposition. When leaves fall to the ground, bacteria feed on the leaves and speed up the decomposition process.

Spotlight on the Rain Forests

Rain forests of South America

More than half of all the world’s rain forests are located in South America. The South American region contains all three types—lowland, montane, and cloud forest—and is dominated by the great Amazon River and its tributaries. The forests of South America claim 2.7 million square miles (7 million square kilometers). The region on the northwest coast of Colombia is not well explored, in contrast to the much-explored forests of northern Brazil. Bordering Paraguay is the Mato Grosso forest. Cloud forests occur in the mountains of Venezuela, Brazil, Peru, and Guyana.

Rain forests of South America

Location: Brazil, Bolivia, Peru, Ecuador, Colombia, Venezuela, Guyana, Surinam, and French Guiana

Annual rainfall is more than 236 inches (600 centimeters), which makes this one of the wettest places in the world.

An estimated 70,000 species of plants can be found in South American rain forests, which includes about 2,500 species of trees. Some trees, such as mahogany and rubber trees, have gained worldwide commercial importance.

No one knows how many species of insects live in the South American rain forest because so many remain to be identified or even discovered. Among those that have been catalogued include the malachite butterfly and the postman butterfly.

More than half of the world’s species of birds make their home in the Amazon basin. A few are migratory but most live in the rain forest year-round. They have the short, broad wings of true jungle birds and range in size from the large-billed toucan to the tiny hummingbird.

Comparatively speaking, this area supports few mammals. They tend to be small and shy and include deer, pacas, agoutis, capybaras, anteaters, tapirs, jaguars, bats, and many species of monkeys, including spider monkeys, woolly monkeys, and capuchins.

In the 1970s, a network of highways was constructed through the Brazilian rain forest in an attempt to develop the land for farming and provide access to mineral and timber resources. This has proved disastrous. Rain forest soil is poor; after a few years farms are abandoned and more land is cleared. In addition, roads are often impassable from January to July, during the season of heaviest rain and severe flooding.

Rain forests of Central America

Before the sixteenth century, the small countries of Central America were covered by rain forest. Forests now cover only about 196,000 square miles (507,000 square kilometers) of land. Some forests are protected, such as the Monteverde Cloud Forest Reserve in Costa Rica.

Rain forests of Central America

Location: Parts of Mexico, Panama, Costa Rica, Nicaragua, Honduras, Guatemala, and Belize

Like the South American forests, the Central American forests are rich in diversity, claiming to have 43,000 to 48,000 different species; 20,000 to 25,000 of these are not found anywhere else in the world. Flowering plants include the hotlips, the brown violet-ear, and many species of orchids. Trees include the massive guanacaste and the Gunnera.

Paper wasps, red-kneed tarantulas, tiger moths, false-leaf katydids, golden beetles, termites, land snails, and sally lightfoot crabs are among the invertebrates that live here. Frogs and toads are exist in great numbers. While some depend on camouflage, others are brightly colored or patterned. Boa constrictors and iguanas are representative of reptiles. Bird life is extremely varied, and Panama supports more species than the whole of North America. Some birds are migratory, spending only the winter months here. Mammals include howler monkeys, tapirs, peccaries, deer, and jaguars.

For more than 3,000 years, Central America was home to the great Aztec and Maya civilizations. The Aztec were centered in Mexico and the Maya in Belize and Guatemala. They were primarily agricultural peoples and had developed methods of irrigating (watering) and fertilizing crops such as corn, beans, and squash. These civilizations also developed forms of writing, books, maps, astronomy, and a very accurate calendar. But by 1521, Hernán Cortés (1485–1547) of Spain had conquered the Aztecs, and by 1550 the Mayans were also overcome and their great civilizations destroyed.

Rain forests of Africa

The lowland wet forest lines the West African coast, from Senegal to the Congo. Montane forest is found in central south Africa. The total area is much smaller than covered by rain forest in South America or Southeast Asia. Here the forest measures about 780,000 square miles (2.02 million square kilometers), or one third of the continent.

Rain forests of Africa

Location: Zaire, Congo, Cameroon, Gabon, Nigeria, Liberia, Sierra Leone, Ivory Coast

The climate in Africa is warm and wet, and annual rainfall is greater than 60 inches (1.5 meters). This helps to support plant and animal life, including the African mahogany, obeche, and ebony trees. African forests are also home to many flowering plants. One, called the “flame of the forest” or the “flamboyant tree” yields huge scarlet flowers. Animals commonly found in the African forest include gorillas, bats, monkeys, apes, and many others.

Rain forests of Madagascar

Rain forest in Madagascar covers the east side of the island along the coast. Rainfall is about 139 inches (353 centimeters) annually. The island is vulnerable to storms at sea and much damage occurs periodically.

Rain forests of Madagascar

Location: Madagascar Island, off the east coast of Africa

Vegetation is dense and of the montane variety. Trees include traveler trees and palms. Ferns, lianas, and epiphytes dominate the understory.

Invertebrates include grasshoppers, termites, cockroaches, mosquitoes, moths, and butterflies. Reptiles include chameleons, geckos, and lizards. Birds are numerous and include guinea fowls, herons, flamingoes, and owls. At one time, Madagascar was part of Africa, and animal life in both places has similar origins. The current island broke away from Africa some 50 million years ago. As a result, the animals in Madagascar developed in isolation, creating a home to many unique species. These include many species of chameleon, the mesite, the lemur, the tenrec, and the fossa.

Rain forests of Southeast Asia

Tropical forests in Asia can be found in Bhutan, Myanmar, Bangladesh, India, the Malay peninsula, Indonesia, and the Philippines. Together, it covers 864,000 square miles (12.2 million square kilometers) of land. Within that, 566,000 square miles (1.47 million square kilometers) is covered in lowland wet forest.

Rain forests of Southeast Asia

Location: Malayasia, Indonesia, the Philippines, Thailand, Cambodia, Laos, and Vietnam

In terms of tree species, the rain forests of Asia differ from others in that they support coniferous trees. The dipterocarps is a large family of hardwoods bearing winged fruits. It dominates these forests. Examples of dipterocarps include the Shorea and Dipterocarpus species. Other trees include kapoks, palms, and even pines. Smaller plants include mosses, ferns, rattans, ginger, orchids, and ant plants.

Asian forests are rich in fruit, such as breadfruit, jackfruit, and durian. Jackfruit is one of the largest fruits in the world, with some species weighing up to 55 pounds (25 kilograms). Durian has a very distinct, unpleasant odor, but is popular among the natives of Asia.

Mammals are well represented and include rats, squirrels, tigers, elephants, rhinoceroses, tapirs, wild pigs, leopards, deer, antelopes, marbled cats, and many species of monkeys and their relatives.

Rain forests of New Guinea

The eastern half of New Guinea, Papau New Guinea, is an independent country, while the western half, Irian Jaya, belongs to Indonesia. As a whole, the island boasts that 77 percent of its lands are mostly lowland wet forests. Ranges of mountains run through the center of the island, the tallest peak is 16,535 feet (5,040 meters) high. Much of this region is unexplored. Steep gorges and rolling valleys punctuate the mountains.

Rain forests of New Guinea

Location: Pacific Ocean, north of Australia

Rainfall is heavy and, on the north coast, totals about 100 inches (254 centimeters) annually. Lowland temperatures remain at about 80°F (27°C) throughout the year.

The forest is rich with kamamere, lancewood, New Guinea base-wood, and walnut. Moretan bay pines and klinki pines can be found at higher altitudes in the montane forest. The klinki pine is the tallest tree in all of the tropical forests in the world, measuring 292 feet (89 meters) tall.

Constant rain removes nutrients from the soil, and most inland soils are poor. In regions around volcanoes soil quality improves. In the montane forests, dead vegetation several feet thick often covers the ground.

Animal life resembles that found in Australia, especially the mammals. Ants, cockroaches, sand flies, butterflies, mosquitoes, and giant snails are representative of invertebrates, and the island is home to many snakes, most of them poisonous. Other reptiles include lizards, tortoises, and crocodiles. Birds are similar to those found in Malaysia and Australia; the cassowary and the bird of paradise are examples. Many mammals are found here, all of which are marsupials (mammals that carry their young in a pouch) except for the spiny anteater, the bat, and non-native rodents. An example of a marsupial is the tree kangaroo.

Native peoples depend upon agriculture, and the rain forest is gradually being cut down to accommodate farms. Crocodile farming is common for the sale of their skins.

For More Information

BOOKS

Allaby, Michael. Biomes of the Earth: Temperate Forests. New York: Chelsea House, 2006.

Allaby, Michael. Biomes of the Earth: Tropical Forests. New York: Chelsea House, 2006.

Fisher, William H. Rain Forest Exchanges: Industry and Community on an Amazonian Frontier. Washington DC: Smithsonian Institution Press, 2000.

Grzimek, Bernhard. Grizmek’s Animal Encyclopedia, 2nd edition. Volume 7. Reptiles, edited by Michael Hutchins, James B. Murphy, and Neil Schlager. Farmington Hills, MI: Gale Group, 2003.

Marent, Thomas, and Ben Morgan. Rainforest. New York: DK Publishing, 2006.

Primack, Richard B., and Richard Corlett. Tropical Rain Forests: An Ecological and Biogeographical Comparison. Hoboken, NJ: Wiley-Blackwell, 2005.

Vandermeer, John H., and Ivette Perfecto Breakfast Of Biodiversity: The Political Ecology of Rain Forest Destruction. Oakland, CA: Food First Books, 2005.

PERIODICALS

Coghlan, Andy. “Earth Suffers as We Gobble Up Resources. “New Scientist. 195. 2611 July 7, 2007: 15.

Darack, Ed. “The Hoh Rainforest. “Weatherwise. 58. 6 Nov-Dec 2005: 20.

Gunnard, Jessie, Andrew Wier and Lynn Margulis. “Mycological Maestros: in the Ecuadorean Rainforest, a ‘Missing Link’ in the Evolution of Termite Agriculture?” Natural History. 112. 4 May 2003: 22.

Stone, Roger D. “Tomorrow’s Amazonia: as Farming, Ranching, and Logging Shrink the Globe’s Great Rainforest, the Planet Heats Up.” The American Prospect. 18. 9 September 2007: A2.

ORGANIZATIONS

African Wildlife Foundation, 1400 16^th Street NW, Suite 120, Washington, DC 20036, Phone: 202-939-3333; Fax: 202-939-3332, Internet: http://www.awf.org.

Environmental Defense Fund, 257 Park Ave. South, New York, NY 10010, Phone: 212-505-2100; Fax: 212-505-2375, Internet: http://www.edf.org.

Environmental Protection Agency, 401 M Street, SW, Washington, DC 20460, Phone: 202-260-2090, Internet: http://www.epa.gov.

Friends of the Earth, 1717 Massachusetts Ave. NW, 300, Washington, DC 20036, Phone: 877-843-8687; Fax: 202-783-0444, Internet: http://www.foe.org.

Greenpeace USA, 702 H Street NW, Washington, DC 20001, Phone: 202-462-1177, Internet: http://www.greenpeace.org.

Rainforest Alliance, 665 Broadway, Suite 500, New York, NY 10012, Phone: 888-MY-EARTH; Fax: 212-677-1900, Internet: http://www.rainforest-alliance.org.

Sierra Club, 85 2^nd Street, 2^nd fl., San Francisco, CA 94105, Phone: 415-977-5500; Fax: 415-977-5799, Internet: http://www.sierraclub.org.

The Wilderness Society, 1615 M st. NW, Washington, DC 20036, Phone: 800-the-wild, Internet: http://www.wilderness.org.

World Wildlife Fund, 1250 24th Street NW, Washington, DC 20090, Internet: http://www.wwf.org.

WEB SITES

National Geographic Magazine. http://www.nationalgeographic.com. (accessed August 22, 2007).

National Park Service. http://www.nps.gov (accessed August 22, 2007).

Nature Conservancy. http://www.tnc.org (accessed August 22, 2007).

Scientific American Magazine. http://www.sciam.com (accessed August 22, 2007).

The World Conservation Union. http://www.iucn.org (accessed August 22, 2007).

World Wildlife Fund. http://www.wwf.org (accessed August 22, 2007).