UWC Grade 5 (2009-2010)

Tropical rainforests have supported humans since ancient times. Although forest life cannot be described as easy, these peoples have built their lives around the surrounding forest and its systems. Consequently, they are a great storehouse of the knowledge about the forest. They know the medicinal properties of plants and understand the value of the forest as an intact ecosystem. As forests fall, these indigenous peoples lose their homes and culture. Conflicts with settlers, who also bring disease and domestic animals, has resulted in the decline of the native population in many areas.

One of the easiest benefits of deforestation to spot are the economic ones. Lumber products are one of the most staple constructive materials in human society. Whether it's raw lumber used for making tables and houses, or paper and other wood by-products, we simply cannot live without the use of lumber. Like steel and stone, wood is one of the most basic natural resources, and unlike steel and stone, it is renewable simply by growing more trees. The only real trick to balancing it's consumption is to grow more trees to replace the ones taken.

his benefit of deforestation not only covers the people who cut down trees and process them, but also extends to the people who "clean up" after them. For every patch of forest cut down, arable land becomes available for farmers, or can be used as an area to place urban living sites like apartments, houses, and buildings. The number of people employed by such a construction project are many and varied. Or, if the city/government mandates replanting trees to replace the lost ones, then jobs are also provided for those people who do the seeding after a patch of forest is stripped.

Because there are so many creatures living in the rainforest, there is a great deal of competition for food, sunlight and space. Some animals became very specialised. This means that they adapted to eating a specific plant or animal that few others eat. For example, parrots and toucans eat nuts, and developed big strong beaks to crack open the tough shells. Leafcutter ants climb tall trees and cut small pieces of leaves which they carry back to their nest.The leaf pieces are about 50 times their weight.The ants bury the leaf pieces, and the combination of the leaves and the ants' saliva encourages the growth of a fungus, which is the only food these ants eat. Sometimes there are relationships between animals and plants that benefit both. Some trees depend on animals to spread the seeds of their fruit to distant parts of the forest. Birds and mammals eat the fruits, and travel some distance before the seeds pass through their digestive systems in another part of the forest. One problem with specialisation is that if one species becomes extinct, the other is in danger too unless it can adapt in time. The dodo, a flightless bird of Mauritius, became extinct in 1681. Today there are just 13 calvaria trees left on the island, each over 300 years old, and nearly at the end of their life. Scientists realised that the seeds had to pass through a dodo's digestive system before they could germinate. It seemed that the tree species would also become extinct, but scientists tried domestic turkeys and have successfully managed to germinate some seeds.Many rainforest animals use camouflage to 'disappear' in the rainforest. Stick insects are perfect examples of this. There are some butterflies whose wings look like leaves. Camouflage is of course useful for predators too, so that they can catch prey that hasn't seen them. The Boa Constrictor is an example of a camouflaged predator. The South American three-toed sloth uses camouflage and amazing slowness to escape predators. Green algae grows in the sloth's fur, which helps camouflage it in the forest canopy. Sloths are among the slowest moving animals of all (inside too, as it takes about a month to digest food). They hang from branches in the canopy, and are so still that predators such as jaguars don't see them. Some animals are poisonous, and use bright colors to warn predators to leave them alone. There are several species of brightly colored poison arrow frogs. Native Central and South American tribes used to wipe the ends of their arrows onto the frog's skin to make their arrows deadly

wood for both timber and wood for making fires; agriculture for both small and large farms; land for poor farmers who don't have anywhere else to live; grazing land for cattle; and road construction

RAINFOREST BIRDS

Tropical rainforests are home to many kinds of mammals

PRIMATES Bolivian Gray Titi Dusky Titi Monkey Ebony Langur Golden Lion Tamarin Gorilla Lemurs Long-Tailed Macaque Macaque Orangutan Proboscis Monkey Squirrel Monkey Wied's Tufted-Eared Marmoset Woolly Monkey CATS Jaguar Ocelot OTHERS African Forest Buffalo African Forest Buffalo Agouti Babirusa Bat Bearded Pig Capybara Coatimundi Elephant Giant Anteater Giant River Otter Malayan Tapir Okapi Sloth Sumatra Rhino Tapir Wild Boar

They regulate global climate patterns and help mitigate negative effects of climate change, specifically, global climate warming, (Service 1), and They serve as storages of global biodiversity, specifically plant and animal diversity (Service 2). Those are the two main factors that have been widely put forward as the arguments which are strong enough for us people to try to do our utmost to “save the rain forests” from their continuous destruction

For example, the deforestation rate of the Amazon rain forest (the largest tropical fain forest in the world) during 2005–2006 was the lowest since 1991. (18)

a choice

The China Conservation and Research Center for the Giant Panda is the most successful center for breeding and caring for endangered giant pandas. The keepers and staff members at the Center take good care of the baby pandas. They care for them from birth until they are old enough to be on their own.©K.Feng/GLOBIO.org The Conservation Center also conducts important research on the surrounding environment. Scientists believe it is important to understand the whole environment and all its species. For example, scientists study the bamboo groves around Wolong. Bamboo is the favorite food

The China Conservation and Research Center for the Giant Panda is the most successful center for breeding and caring for endangered giant pandas. The keepers and staff members at the Center take good care of the baby pandas. They care for them from birth until they are old enough to be on their own.

Today, we know that the soil of the tropical rainforests is thin and very low in nutrients. Decomposers like leaf-cutter ants, termites, bacteria, and fungi quickly turn falling leaves and dead organisms into nutrients. Plants take up these nutrients the moment they are available, so they don’t get a chance to enrich the soil. Keeping Tropical Rainforests Healthy Conservation of tropical rainforests should be easy. They have survived for millions of years. The trick to keeping them healthy is to not take too much too fast. This gives the rainforests time to recover from human activities like logging. But many countries that have tropical rainforests are poor. They can make money by cutting down and developing the rainforests. But uncontrolled development results in deforestation

Rainforests have 170,000 of the world's 400,000 known plant species. The United States has 81 species of frogs, while Madagascar (which is smaller than Texas) may have 300 species. Europe has 321 butterfly species, while Manu National Park in the tropical rainforest of Peru has 1,300 species! The world’s only species of flying snake and lizard live in the Borneo rainforest. The largest catfish in the world lives in a tropical rainforest river in Vietnam. It weighs over 300 kg. About one-quarter of all the medicines we use come from rainforest plants. Curare comes from a tropical vine. It is used as an anesthetic and to relax muscles during heart surgery. Quinine, from the cinchona tree, is used to treat malaria. A person with leukemia has a 99% chance that the disease will go into remission because of the rosy periwinkle. More than 1,400 varieties of tropical plants might be potential cures for cancer.

Some traditional rainforest cultures still live in the forests. They travel as a group to collect and hunt food. As rainforests are destroyed, so are the homes of these interesting and amazing people.

The tallest trees are the emergents, towering as much as 200 feet above the forest floor with trunks that measure up to 16 feet around.   Most of these trees are broad-leaved, hardwood evergreens. Sunlight is plentiful up here.  Animals found are eagles, monkeys, bats and butterflies. CANOPY LAYER This is the primary layer of the forest and forms a roof over the two remaining layers.   Most canopy trees have smooth, oval leaves that come to a point. It's a maze of leaves and branches.  Many animals live in this area since food is abundant.   Those animals include: snakes, toucans and treefrogs. UNDERSTORY LAYER Little sunshine reaches this area so the plants have to grow larger leaves to reach the sunlight.   The plants in this area seldom grow to 12 feet.  Many animals live here including jaguars, red-eyed tree frogs and leopards.  There is a large concentration of insects here. FOREST FLOOR It's very dark down here.  Almost no plants grow in this area, as a result.  Since hardly any sun reaches the forest floor things begin to decay quickly.  A leaf that might take one year to decompose in a regular climate will disappear in  6 weeks.   Giant anteaters live in this layer.

The Sumatran rhinoceros is a small, hairy rhinoceros which survives in limited numbers in pockets of Indonesian and Malaysian rain forests. In the early 1900s it ranged over most of Southeast Asia from the Himalayas in Bhutan, eastern India through Malaysia, Sumatra and Borneo. Now they are only found in little forest pockets on the Indonesian island of Sumatra and the Malay peninsula.

The smallest living rhinoceros, the Sumatran rhinoceros has a gray-brown leathery hide. Its deep folds around the neck, behind the front legs, and before the hind legs give the rhinoceros an armor-plated appearance. It has a short, stocky body and stumpy legs which are covered with coarse reddish-brown hair. Its body length is from 8 to 8.5 feet and stands 4.5 feet at the shoulders. A mature rhino weighs from 2200 to 4400 pounds.

The Sumatran rhinoceros is the only Asian rhinoceros with two horns. Both sexes of rhinos have horns, the front horn being larger, averaging 15 to 20 inches. The male's horns are usually bigger than the female's, whose second, smaller horn is often absent. The upper lip curves down and can move around to grasp objects.

Many species of animal life can be found in the rain forest. Common characteristics found among mammals and birds (and reptiles and amphibians, too) include adaptations to a life in the trees, such as the prehensile tails of New World monkeys. Other characteristics are bright colors and sharp patterns, loud vocalizations, and diets heavy on fruits. Insects make up the largest single group of animals that live in tropical forests. They include brightly colored butterflies, mosquitoes, camouflaged stick insects, and huge colonies of ants. The Amazon river basin rainforest contains a wider variety of plant and animal life than any other biome in the world. The second largest population of plant and animal life can be found in scattered locations and islands of Southeast Asia. The lowest variety can be found in Africa. There may be 40 to 100 different species in 2.5 acres ( 1 hectare) of a tropical rain forest.   When early explorers first discovered the rainforests of Africa, Southeast Asia and South America, they They were amazed by the dense growth, trees with giant buttresses, vines and epiphytes . The tropical vegetation grew so dense that it was difficult to cut one's way through it. It was thought at the time that the soil of a rainforest must be very fertile, filled with nutrients, enabling it to support the immense trees and other vegetation they found. Today we know that the soil of the tropical rainforests is shallow, very poor in nutrients and almost without soluble minerals. Thousands of years of heavy rains have washed away the nutrients in the soil obtained from weathered rocks. The rainforest has a very short nutrient cycle. Nutrients generally stay in an ecosystem by being recycled and in a rainforest are mainly found in the living plants and the layers of decomposing leaf litter. Various species of decomposers like insects, bacteria, and fungi make quick work of turning dead plant and animal matter into nutrients. Plants take up these nutrients the moment they are released. A study in the Amazon rainforest found that 99% of nutrients are held in root mats. When a rainforest is burned or cut down the nutrients are removed from the ecosystem. The soil can only be used for a very short time before it becomes completely depleted of all nutrients.

Besides these four layers, a shrub/sapling layer receives about 3 % of the light that filters in through the canopies. These stunted trees are capable of a sudden growth surge when a gap in the canopy opens above them. The air beneath the lower canopy is almost always humid. The trees themselves give off water through the pores (stomata) of their leaves. This process, called transpiration, can account for as much as half of the precipitation in the rain forest. Rainforest plants have made many adaptations to their environment. With over 80 inches of rain per year, plants have made adaptations that helps them shed water off their leaves quickly so the branches don't get weighed down and break. Many plants have drip tips and grooved leaves, and some leaves have oily coatings to shed water. To absorb as much sunlight as possible on the dark understory, leaves are very large. Some trees have leaf stalks that turn with the movement of the sun so they always absorb the maximum amount of light. Leaves in the upper canopy are dark green, small and leathery to reduce water loss in the strong sunlight. Some trees will grow large leaves at the lower canopy level and small leaves in the upper canopy. Other 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. Over 2,500 species of vines grow in the rainforest. Lianas start off as small shrubs that grow on the forest floor. To reach the sunlight in the upper canopy it sends out tendrils to grab sapling trees. The liana and the tree grow towards the canopy together. The vines grow from one tree to another and make up 40% of the canopy leaves. The rattan vine has spikes on the underside of its leaves that point backwards to grab onto sapling trees. Other "strangler" vines will use trees as support and grow thicker and thicker as they reach the canopy, strangling its host tree. They look like trees whose centers have been hollowed out. Dominant species do not exist in tropical rainforests. Lowland dipterocarp forest can consist of many different species of Dipterocarpaceae, but not all of the same species. Trees of the same species are very seldom found growing close together. This bio diversity and separation of the species prevents mass contamination and die-off from disease or insect infestation. Bio diversity also insures that there will be enough pollinators to take care of each species' needs. Animals depend on the staggered blooming and fruiting of rainforest plants to supply them with a year-round source of food.

There are four very distinct layers of trees in a tropical rain forest. These layers have been identified as the emergent, upper canopy, understory, and forest floor. Emergent trees are spaced wide apart, and are 100 to 240 feet tall with umbrella-shaped canopies that grow above the forest. Because emergent trees are exposed to drying winds, they tend to have small, pointed leaves. Some species lose their leaves during the brief dry season in monsoon rainforests. These giant trees have straight, smooth trunks with few branches. Their root system is very shallow, and to support their size they grow buttresses that can spread out to a distance of 30 feet. The upper canopy of 60 to 130 foot trees allows light to be easily available at the top of this layer, but greatly reduced any light below it. Most of the rainforest's animals live in the upper canopy. There is so much food available at this level that some animals never go down to the forest floor. The leaves have "drip spouts" that allows rain to run off. This keeps them dry and prevents mold and mildew from forming in the humid environment. The understory, or lower canopy, consists of 60 foot trees. This layer is made up of the trunks of canopy trees, shrubs, plants and small trees. There is little air movement. As a result the humidity is constantly high. This level is in constant shade. The forest floor is usually completely shaded, except where a canopy tree has fallen and created an opening. 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. Less than 1 % of the light that strikes the top of the forest penetrates to the forest floor. The top soil is very thin and of poor quality. A lot of litter falls to the ground where it is quickly broken down by decomposers like termites, earthworms and fungi. The heat and humidity further help to break down the litter. This organic matter is then just as quickly absorbed by the trees' shallow roots