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47-483: The park protects most of the island's remaining rainforest although much of this has been degraded by introduced plants such as Chinese guava and privet and animals such as rusa deer and wild pigs . Several areas have been fenced off and invasive species have been eradicated from them to preserve native wildlife. Many endemic plants and animals still occur in the park including the Mauritian flying fox and all of

94-507: A millennium . This wobble means that the Tropic of Cancer is currently drifting southward at a rate of almost half an arcsecond (0.468″) of latitude, or 15 m (49 ft), per year. The circle's position was at exactly 23° 27′N in 1917 and will be at 23° 26'N in 2045. The distance between the Antarctic Circle and the Tropic of Cancer is essentially constant as they move in tandem. This

141-629: A large loss of Amazonian rainforest around 2050 due to drought , forest dieback and the subsequent release of more carbon dioxide. Tropical rainforests provide timber as well as animal products such as meat and hides. Rainforests also have value as tourism destinations and for the ecosystem services provided. Many foods originally came from tropical forests, and are still mostly grown on plantations in regions that were formerly primary forest. Also, plant-derived medicines are commonly used for fever, fungal infections, burns, gastrointestinal problems, pain, respiratory problems, and wound treatment. At

188-423: A more open canopy layer than other rainforests, and are found in areas of lower rainfall (630–1,100 mm (25–43 in)). They generally have two layers of trees. A tropical rainforest typically has a number of layers, each with different plants and animals adapted for life in that particular area. Examples include the emergent, canopy , understory and forest floor layers. The emergent layer contains

235-639: A national emergency. Amazon deforestation jumped by 69% in 2008 compared to 2007's twelve months, according to official government data. However, a January 30, 2009 New York Times article stated, "By one estimate, for every acre of rainforest cut down each year, more than 50 acres of new forest are growing in the tropics." The new forest includes secondary forest on former farmland and so-called degraded forest . Tropic of Cancer 23°26′12.5″N 0°0′0″W  /  23.436806°N -0.00000°E  / 23.436806; -0.00000  ( Prime Meridian ) The Tropic of Cancer , also known as

282-513: A small net impact on atmospheric carbon dioxide levels, though they may have other climatic effects (on cloud formation, for example, by recycling water vapour ). No rainforest today can be considered to be undisturbed. Human-induced deforestation plays a significant role in causing rainforests to release carbon dioxide, as do other factors, whether human-induced or natural, which result in tree death, such as burning and drought. Some climate models operating with interactive vegetation predict

329-407: A small number of very large trees called emergents , which grow above the general canopy , reaching heights of 45–55 m, although on occasion a few species will grow to 70–80 m tall. They need to be able to withstand the hot temperatures and strong winds that occur above the canopy in some areas. Eagles , butterflies , bats and certain monkeys inhabit this layer. The canopy layer contains

376-797: A study by Colin Turnbull , The Forest People , in 1962. Pygmies who live in Southeast Asia are, amongst others, referred to as " Negrito ". There are many tribes in the rainforests of the Malaysian state of Sarawak. Sarawak is part of Borneo, the third largest island in the world. Some of the other tribes in Sarawak are: the Kayan, Kenyah, Kejaman, Kelabit, Punan Bah, Tanjong, Sekapan, and the Lahanan. Collectively, they are referred to as Dayaks or Orangulu which means "people of

423-437: A trend towards declining populations in rainforests, for example, reptiles that feed on amphibians and reptiles. This trend requires close monitoring. The seasonality of rainforests affects the reproductive patterns of amphibians, and this in turn can directly affect the species of reptiles that feed on these groups, particularly species with specialized feeding, since these are less likely to use alternative resources. Despite

470-436: A very broad array of fauna , including mammals , reptiles , amphibians , birds and invertebrates . Mammals may include primates , felids and other families. Reptiles include snakes , turtles , chameleons and other families; while birds include such families as vangidae and Cuculidae . Dozens of families of invertebrates are found in rainforests. Fungi are also very common in rainforest areas as they can feed on

517-423: A warm and wet climate with no substantial dry season: typically found within 10 degrees north and south of the equator . Mean monthly temperatures exceed 18 °C (64 °F) during all months of the year. Average annual rainfall is no less than 168 cm (66 in) and can exceed 1,000 cm (390 in) although it typically lies between 175 cm (69 in) and 200 cm (79 in). Many of

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564-476: Is a stub . You can help Misplaced Pages by expanding it . Rainforest Rainforests are forests characterized by a closed and continuous tree canopy , moisture-dependent vegetation, the presence of epiphytes and lianas and the absence of wildfire. Rainforests can be generally classified as tropical rainforests or temperate rainforests , but other types have been described. Estimates vary from 40% to 75% of all biotic species being indigenous to

611-503: Is abundant. Many seedlings that will grow to the canopy level are present in the understory. Only about 5% of the sunlight shining on the rainforest canopy reaches the understory. This layer can be called a shrub layer , although the shrub layer may also be considered a separate layer. The forest floor , the bottom-most layer, receives only 2% of the sunlight. Only plants adapted to low light can grow in this region. Away from riverbanks , swamps and clearings, where dense undergrowth

658-564: Is based on an assumption of a constant equator, but the precise location of the equator is not truly fixed. See: equator , axial tilt and circles of latitude for additional details. Download coordinates as: North of the tropic are the subtropics and the North Temperate Zone . The equivalent line of latitude south of the Equator is called the Tropic of Capricorn , and the region between

705-419: Is found, the forest floor is relatively clear of vegetation because of the low sunlight penetration. It also contains decaying plant and animal matter, which disappears quickly, because the warm, humid conditions promote rapid decay. Many forms of fungi growing here help decay the animal and plant waste. More than half of the world's species of plants and animals are found in rainforests. Rainforests support

752-546: The Cameroon to the Congo ( Congo Rainforest ), South America (e.g. the Amazon rainforest ), Central America (e.g. Bosawás , the southern Yucatán Peninsula - El Peten - Belize - Calakmul ), Australia , and on Pacific Islands (such as Hawaiʻi ). Tropical forests have been called the "Earth's lungs ", although it is now known that rainforests contribute little net oxygen addition to

799-611: The Equator . Its Southern Hemisphere counterpart, marking the most southerly position at which the Sun can be seen directly overhead, is the Tropic of Capricorn . These tropics are two of the five major circles of latitude that mark maps of Earth, the others being the Arctic and Antarctic circles and the Equator . The positions of these two circles of latitude (relative to the Equator) are dictated by

846-752: The Northern Tropic , is the Earth 's northernmost circle of latitude where the Sun can be seen directly overhead . This occurs on the June solstice , when the Northern Hemisphere is tilted toward the Sun to its maximum extent. It also reaches 90 degrees below the horizon at solar midnight on the December Solstice . Using a continuously updated formula, the circle is currently 23°26′09.8″ (or 23.43605°) north of

893-680: The atmosphere through photosynthesis . Tropical forests cover a large part of the globe, but temperate rainforests only occur in a few regions around the world. Temperate rainforests are rainforests in temperate regions. They occur in North America (in the Pacific Northwest in Alaska , British Columbia , Washington , Oregon and California ), in Europe (parts of the British Isles such as

940-400: The 20th century and the area covered by rainforests around the world is shrinking. Biologists have estimated that large numbers of species are being driven to extinction (possibly more than 50,000 a year; at that rate, says E. O. Wilson of Harvard University , a quarter or more of all species on Earth could be exterminated within 50 years) due to the removal of habitat with destruction of

987-465: The Earth, but one to two hundred feet above it, extending over thousands of square miles." A true exploration of this habitat only began in the 1980s, when scientists developed methods to reach the canopy, such as firing ropes into the trees using crossbows . Exploration of the canopy is still in its infancy, but other methods include the use of balloons and airships to float above the highest branches and

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1034-456: The Tropic of Cancer experience two distinct seasons: an extremely hot summer with temperatures often reaching 45 °C (113 °F) and a warm winter with maxima around 22 °C (72 °F). Much land on or near the Tropic of Cancer is part of the Sahara Desert , while to the east, the climate is torrid monsoonal with a short wet season from June to September, and very little rainfall for

1081-464: The building of cranes and walkways planted on the forest floor. The science of accessing tropical forest canopy using airships or similar aerial platforms is called dendronautics . The understory or understorey layer lies 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 , boa constrictors and leopards . The leaves are much larger at this level and insect life

1128-805: The coastal areas of Ireland and Scotland , southern Norway , parts of the western Balkans along the Adriatic coast, as well as in Galicia and coastal areas of the eastern Black Sea , including Georgia and coastal Turkey ), in East Asia (in southern China , Highlands of Taiwan , much of Japan and Korea , and on Sakhalin Island and the adjacent Russian Far East coast), in South America (southern Chile ) and also in Australia and New Zealand . Dry rainforests have

1175-417: The decomposing remains of plants and animals. The great diversity in rainforest species is in large part the result of diverse and numerous physical refuges , i.e. places in which plants are inaccessible to many herbivores, or in which animals can hide from predators. Having numerous refuges available also results in much higher total biomass than would otherwise be possible. Some species of fauna show

1222-448: The fact that the Sun appears to "turn back" at the solstices. The Tropic of Cancer's position is not fixed, but constantly changes because of a slight wobble in the Earth's longitudinal alignment relative to the ecliptic , the plane in which the Earth orbits around the Sun. Earth's axial tilt varies over a 41,000-year period from about 22.1 to 24.5 degrees, and as of 2000 is about 23.4 degrees, which will continue to remain valid for about

1269-479: The following 17 countries (including two disputed territories) and 8 water bodies, starting at the prime meridian and heading eastward: The climate at the Tropic of Cancer is generally hot and dry, except for cooler highland regions in China, marine environments such as Hawaii, and easterly coastal areas, where orographic rainfall can be very heavy, in some places reaching 4 metres (160 in) annually. Most regions on

1316-422: The growth of vegetation in a tropical rainforest, soil quality is often quite poor. Rapid bacterial decay prevents the accumulation of humus . The concentration of iron and aluminium oxides by the laterization process gives the oxisols a bright red colour and sometimes produces mineral deposits such as bauxite . Most trees have roots near the surface because there are insufficient nutrients below

1363-468: The increasing deforestation rate, especially in Indonesia, is the expansion of oil palm plantations to meet growing demand for cheap vegetable fats and biofuels . In Indonesia, palm oil is already cultivated on nine million hectares and, together with Malaysia , the island nation produces about 85 percent of the world's palm oil. Several countries, notably Brazil , have declared their deforestation

1410-469: The interior". About half of Sarawak's 1.5 million people are Dayaks. Most Dayaks, it is believed by anthropologists, came originally from the South-East Asian mainland. Their mythologies support this. Tropical and temperate rainforests have been subjected to heavy legal and illegal logging for their valuable hardwoods and agricultural clearance ( slash-and-burn , clearcutting ) throughout

1457-506: The island of New Guinea is home to an estimated 44 uncontacted tribal groups. The tribes are in danger because of the deforestation, especially in Brazil. Central African rainforest is home of the Mbuti pygmies , one of the hunter-gatherer peoples living in equatorial rainforests characterised by their short height (below one and a half metres, or 59 inches, on average). They were the subject of

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1504-441: The island's endemic birds: Mauritius kestrel , pink pigeon , Mauritius parakeet , Mauritius cuckooshrike , Mauritius bulbul , Mauritius olive white-eye , Mauritius grey white-eye and Mauritius fody . The park has been designated an Important Bird Area (IBA) by BirdLife International . 20°25′S 57°25′E  /  20.417°S 57.417°E  / -20.417; 57.417 This Mauritius location article

1551-437: The majority of the largest trees, typically 30 metres (98 ft) to 45 metres (148 ft) tall. The densest areas of biodiversity are found in the forest canopy, a more or less continuous cover of foliage formed by adjacent treetops. The canopy, by some estimates, is home to 50 percent of all plant species. Epiphytic plants attach to trunks and branches , and obtain water and minerals from rain and debris that collects on

1598-473: The poor soil quality. First is that the soil is highly acidic. The roots of plants rely on an acidity difference between the roots and the soil in order to absorb nutrients. When the soil is acidic, there is little difference, and therefore little absorption of nutrients from the soil. Second, the type of clay particles present in tropical rainforest soil has a poor ability to trap nutrients and stop them from washing away. Even if humans artificially add nutrients to

1645-703: The rainforests. Another factor causing the loss of rainforest is expanding urban areas . Littoral rainforest growing along coastal areas of eastern Australia is now rare due to ribbon development to accommodate the demand for seachange lifestyles. Forests are being destroyed at a rapid pace. Almost 90% of West Africa 's rainforest has been destroyed. Since the arrival of humans, Madagascar has lost two thirds of its original rainforest. At present rates, tropical rainforests in Indonesia would be logged out in 10 years and Papua New Guinea in 13 to 16 years. According to Rainforest Rescue , an important reason for

1692-420: The rainforests. There may be many millions of species of plants, insects and microorganisms still undiscovered in tropical rainforests. Tropical rainforests have been called the "jewels of the Earth" and the " world's largest pharmacy ", because over one quarter of natural medicines have been discovered there. Rainforests as well as endemic rainforest species are rapidly disappearing due to deforestation ,

1739-678: The rest of the year. The highest mountain on or adjacent to the Tropic of Cancer is Yu Shan in Taiwan . It had glaciers descending as low as 2,800 metres (9,190 ft) during the Last Glacial Maximum . At present glaciers still exist around the Tropic. The nearest currently surviving are the Minyong and Baishui in the Himalayas to the north and on Iztaccíhuatl in Mexico to the south. According to

1786-581: The resulting habitat loss and pollution of the atmosphere . Rainforests are characterized by a closed and continuous tree canopy, high humidity, the presence of moisture-dependent vegetation, a moist layer of leaf litter, the presence of epiphytes and lianas and the absence of wildfire. The largest areas of rainforest are tropical or temperate rainforests, but other vegetation associations including subtropical rainforest , littoral rainforest , cloud forest , vine thicket and even dry rainforest have been described. Tropical rainforests are characterized by

1833-488: The rules of the Fédération Aéronautique Internationale , for a flight to compete for a round-the-world speed record, it must cover a distance no less than the length of the Tropic of Cancer, cross all meridians , and end on the same airfield where it started. The length of the Tropic of Cancer is 36,788 km (22,859 mi): For an ordinary circumnavigation the rules are somewhat relaxed and

1880-482: The same time, rainforests are usually not used sustainably by non-native peoples but are being exploited or removed for agricultural purposes . On January 18, 2007, FUNAI reported also that it had confirmed the presence of 67 different uncontacted tribes in Brazil, up from 40 in 2005. With this addition, Brazil has now overtaken the island of New Guinea as the country having the largest number of uncontacted tribes. The province of Irian Jaya or West Papua in

1927-421: The soil, the nutrients mostly wash away and are not absorbed by the plants. Finally, these soils are poor due to the high volume of rain in tropical rainforests washes nutrients out of the soil more quickly than in other climates. A natural rainforest emits and absorbs vast quantities of carbon dioxide . On a global scale, long-term fluxes are approximately in balance, so that an undisturbed rainforest would have

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1974-443: The supporting plants. The fauna is similar to that found in the emergent layer but 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 only recently developed practical methods of exploring it. As long ago as 1917, naturalist William Beebe declared that "another continent of life remains to be discovered, not upon

2021-433: The surface; most of the trees' minerals come from the top layer of decomposing leaves and animals. On younger substrates, especially of volcanic origin, tropical soils may be quite fertile. If rainforest trees are cleared, rain can accumulate on the exposed soil surfaces, creating run-off, and beginning a process of soil erosion . Eventually, streams and rivers form and flooding becomes possible. There are several reasons for

2068-402: The tilt of Earth's axis of rotation relative to the plane of its orbit , and since the tilt changes, the location of these two circles also changes. In geopolitics , it is known for being the southern limitation on the mutual defence obligation of NATO , as member states of NATO are not obligated to come to the defence of territory south of the Tropic of Cancer. When this line of latitude

2115-401: The two, centered on the Equator, is the tropics . In the year 2000, more than half of the world's population lived north of the Tropic of Cancer. On the Tropic of Cancer there are approximately 13 hours, 35 minutes of daylight during the summer solstice. During the winter solstice, there are 10 hours, 41 minutes of daylight. Using 23°26'N for the Tropic of Cancer, the tropic passes through

2162-716: 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 moist forests are located in the equatorial zone between the 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

2209-522: Was named in the last centuries BCE , the Sun was in the constellation Cancer ( Latin : Crab ) at the June solstice (90° ecliptic longitude ). Due to the precession of the equinoxes , this is no longer the case; today the Sun is in constellation Taurus at the June solstice. The word "tropic" itself comes from the Greek "trope (τροπή)", meaning turn (change of direction or circumstance), inclination, referring to

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