Rainforests are forests that are characterized by high rainfall, with annual rainfall in cases of tropical rainforest between 250 and 450 cm (98 and 177 Â ° deep), and the definition varies by region for temperate rainforests. The rain trench, otherwise known as the intertropical convergence zone, plays an important role in creating the necessary climatic conditions for the Earth's tropical rainforest.
Approximately 40% to 75% of all biotic species come from the rainforest. There may be millions of plant species, insects and microorganisms that are still missing in tropical rainforests. Tropical rain forests have been called "Earth gems" and "the largest pharmacies in the world", as more than a quarter of the natural remedies have been found there. Rainforests are also responsible for 28% of the world's oxygen turnover, sometimes incorrectly mentioning oxygen production, processing it through photosynthesis from carbon dioxide and consuming it through respiration.
Dew in some areas of rainforest can be limited by the penetration of bad sunlight to the soil surface. If the leaf canopy is crushed or thinned, the soil beneath is immediately colonized by vines, shrubs and dense, tangled little trees, called forests. The term jungle is also occasionally applied to common tropical rainforests.
Rainforests as well as endemic rainforest species are rapidly disappearing due to deforestation, habitat loss and atmospheric pollution.
Video Rainforest
Tropis
Tropical rainforest is characterized by a warm and wet climate with no significant droughts: usually found in 10 degrees north and south of the equator. Means the monthly temperature exceeds 18Ã, Â ° C (64Ã, Â ° F) for all months of the year. Average annual rainfall is not less than 168 cm (66 inches) and can exceed 1,000 cm (390 inches) although it is usually located between 175 cm (69 inches) and 200 cm (79 inches).
Many of the world's tropical forests are associated with the location of the monsoon trough, also known as the intertropical convergence zone. The broader category of tropical wet forests lies in the equatorial zone between Tropic of Cancer and Tropic of Capricorn. Tropical rainforests exist in Southeast Asia (from Myanmar (Burma)) to the Philippines, Malaysia, Indonesia, Papua New Guinea and Sri Lanka; also in Sub-Saharan Africa from Cameroon to Congo (Congo Rainforest), South America (eg the Amazon rain forest), Central America (eg BosawÃÆ'¡s, South YucatÃÆ'¡n-El Peten-Belize-Calakmul), Australia, and in the Pacific Islands (such as Hawaii ? i). Tropical forests have been called "Earth's lungs", although it is now known that rainforests contribute a small amount of net oxygen to the atmosphere through photosynthesis.
Maps Rainforest
Temperate
Tropical forests cover most of the globe, but temperate rain forests occur only in a few regions around the world. Rainforest is rain forest in temperate regions. They occur in North America (in the Northwest Pacific in Alaska, British Columbia, Washington, Oregon and California), in Europe (parts of the British Isles such as the coastal regions of Ireland and Scotland, southern Norway, parts of the western Balkans along the Adriatic coast, in Galicia and the eastern coastal areas of the Black Sea, including Georgia and the coast of Turkey), in East Asia (in southern China, the Taiwan Highlands, mostly Japan and Korea, and on Sakhalin Island and the vicinity of Russia's Far East Coast), in South America (Southern Chile) and also in Australia and New Zealand.
Layers
Tropical rainforests usually have a number of layers, each with different plants and animals adapted for life in the area. Examples include emerging floor layers, canopies, understory and woods.
Appears layer
The layer that appears contains a small number of very large trees called appear , which grow above the public canopy, reaching a height of 45-55 m, though sometimes some species will grow up to 70-80 m. They should be able to withstand the hot temperatures and strong winds that occur above the canopy in some areas. Eloves, butterflies, bats, and certain monkeys inhabit this layer.
Canopy layer
The canopy layer contains most of the largest trees, typically 30 meters (98Ã, ft) up to 45 meters (148Ã, ft) high. The most densely populated areas of biodiversity are found in forest canopy, more or less a continuous cover of the leaves formed by adjacent tree shoots. The canopy, with some estimates, is home to 50 percent of all plant species. Epiphytic plants attach to the stems and branches, and obtain water and minerals from rain and debris collected in supporting plants. These fauna are similar to those found in the emerging layer, but are more diverse. A quarter of all insect species are believed to exist in the rainforest canopy. Scientists have long suspected the richness of the canopy as a habitat, but have recently developed practical methods to explore it. Since 1917, naturalist William Beebe stated that "another continent of life must still be found, not on Earth, but one to two hundred meters above it, extending for thousands of square miles." True exploration of this habitat only began in the 1980s, when scientists developed methods to reach the canopy, such as firing ropes into trees using a bow. Canopy exploration is still in its early stages, but other methods include the use of balloons and aircraft to float above the highest branches and the construction of cranes and trails planted on the forest floor. Science accesses tropical forest canopy using airships or similar air platforms called dendronautics.
Understanding layer
The understory or understorey layer is located between the canopy and the forest floor. It is home to a number of birds, snakes and lizards, as well as predators such as jaguars, snakes and leopards. The leaves are much larger at this level and the life of insects is abundant. Many seeds that will grow to the level of canopy present in understory. Only about 5% of the sunlight that shines on the rainforest canopy reaches the bottom. This layer can be called a layer of shrub , although the shrub layer can also be considered as a separate layer.
Forest floor
forest floor , the lowest layer, only receive 2% of sunlight. Only plants that adapt to low light that can grow in this region. Away from the banks of rivers, swamps and open fields, where dense bushes are found, the forest floor is relatively clean from vegetation due to low sunlight penetration. It also contains rotting plant and animal matter, which disappears quickly, as warm and humid conditions promote rapid decay. Many forms of fungus that grow here help to shed the feces of animals and plants.
Flora and fauna
More than half of the world's plant and animal species are found in the rainforest. Rainforests support a wide variety of fauna, including mammals, reptiles, birds and invertebrates. Mammals include primates, felida and other families. Reptiles include snakes, turtles, chameleons and other families; while birds include families such as vangidae and Cuculidae. Dozens of invertebrate families are found in the rainforest. Mushrooms are also very common in rain forest areas because they can eat the remains of rotting plants and animals.
Land
Despite the growth of vegetation in tropical rainforests, soil quality is often quite bad. Rapid bacterial decay prevents the accumulation of humus. The concentrations of iron oxide and aluminum by lateralization process provide a bright red oxide and sometimes produce mineral deposits such as bauxite. Most trees have roots near the surface, because there is enough nutrients beneath the surface; most of the tree minerals come from the top layer of decaying leaves and animals. On younger substrates, especially volcanic origin, tropical soil may be quite fertile. If rainforest trees are cleared, rain can accumulate on open ground, create runoff and begin soil erosion processes. Eventually streams and streams and floods became possible.
Effect on global climate
Natural rainforests emit and absorb large amounts of carbon dioxide. On a global scale, long-term flux is approximately balanced, so undisturbed rainforests will have little impact on atmospheric carbon dioxide levels, although they may have other climatic effects (on cloud formation, for example, by recycling water vapor). There is no rain forest at this time that can be considered undisturbed. Human-induced deforestation plays an important role in causing rainforests to release carbon dioxide, as do other factors, whether human or natural, resulting in tree deaths, such as burning and drought. Some climate models that operate with interactive vegetation predict the loss of the Amazon rainforest around 2050 due to drought, dieback forest and the release of more carbon dioxide. Five million years from now, the Amazon rainforest may have long drained and transformed itself into a savanna, killing itself in progress (changes like this can happen even if all human logging activities stop overnight).
Human use
Tropical rain forests provide wood and animal products such as meat and leather. Rainforests also have value as a tourist destination and for ecosystem services are provided. Many foods come from tropical forests, and most are still grown on plantations in formerly primary forests. Also, plant-derived drugs are commonly used for fever, fungal infections, burns, digestive problems, pain, respiratory problems, and wound care. At the same time, rainforests are not normally used sustainably by non-native communities but are exploited or removed for agricultural purposes.
Native people
On January 18, 2007, FUNAI reported also that they have confirmed the presence of 67 non-contracted tribes in Brazil, up from 40 in 2005. With this addition, Brazil has now taken over the island of New Guinea as a country that has the largest number of tribes that do not contaminated. The province of Irian Jaya or West Papua on the island of New Guinea is home to about 44 non-contracted tribal groups. The tribes are threatened by deforestation, especially in Brazil.
The Central African rain forest is the home of the Mbuti pygmies, one of the hunter-gatherer communities living in equatorial rainforests characterized by their short height (under one and a half meters, or 59 inches, on average). They were the subject of research by Colin Turnbull, The Forest People , in 1962. Pygmies living in Southeast Asia, among others, are referred to as "Negritos".
Deforestation
Tropical and temperate rainforests have heavy legal and illegal logging for hardwoods and their valuable agricultural logging (cutting-and-burn, clearcutting) throughout the 20th century and areas covered by rainforests around the world are shrinking. Biologists have estimated that a large number of species are being endangered (perhaps more than 50,000 per year, at that level, says EO Wilson of Harvard University, a quarter or more of all species on Earth could be destroyed within 50 years) due to habitat removal by rainforest destruction.
Another factor causing rainforest loss is the expansion of urban areas. Littoral rainforests that grow along the eastern coast of Australia are now rare due to the development of tape to accommodate demand for seachange lifestyles.
Forests are destroyed very quickly. Nearly 90% of West African rain forests have been destroyed. Since the arrival of humans, Madagascar has lost two-thirds of its original rainforest. At present, tropical rainforests in Indonesia will be exhausted in 10 years and Papua New Guinea in 13 to 16 years. According to Rainforest Rescue, an important reason for increasing deforestation rates, especially in Indonesia, is the expansion of oil palm plantations to meet the growing demand for cheap vegetable fats and biofuels. In Indonesia, oil palm has been cultivated on nine million hectares and, together with Malaysia, the island nation produces about 85 percent of the world's palm oil.
Some countries, especially Brazil, have declared their deforestation a national emergency. Amazon deforestation jumped by 69% in 2008 compared to twelve months in 2007, according to official government data.
However, an article in the New York Times on January 30, 2009 states, "With one estimate, for every hectare of rainforests being cut annually, more than 50 hectares of new forest grow in the tropics..." The new forest includes secondary forest forests on former agricultural land and so-called degraded forests.
See also
References
Further reading
- Butler, R. A. (2005) Out of Time Places: Tropical Rain Forests and Their Dangers . Published online: Rainforests.mongabay.com
- Richards, P. W. (1996). tropical rainforest . 2nd Edition. Cambridge University Press ISBN: 0-521-42194-2
- Whitmore, T. C. (1998) Introduction to tropical rainforests . 2nd Edition. Oxford University Press. ISBNÃ, 0-19-850147-1
External links
Source of the article : Wikipedia
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