Misplaced Pages

#10989

59-488: 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

118-554: A sphere flattened 0.336% along its axis. This makes the Equator 0.16% longer than a meridian (a great circle passing through the two poles). The IUGG standard meridian is, to the nearest millimetre, 40,007.862917 kilometres (24,859.733480 mi), one arc-minute of which is 1,852.216 metres (6,076.82 ft), explaining the SI standardization of the nautical mile as 1,852 metres (6,076 ft), more than 3 metres (9.8 ft) less than

177-504: A 12-hour day and 12-hour night. The name is derived from medieval Latin word aequator , in the phrase circulus aequator diei et noctis , meaning 'circle equalizing day and night', from the Latin word aequare 'make equal'. The latitude of the Earth's equator is, by definition, 0° (zero degrees ) of arc. The equator is one of the five notable circles of latitude on Earth;

236-629: 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

295-423: 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

354-461: 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 . Equator The equator

413-513: 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

472-407: 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

531-828: 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

590-437: 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

649-436: 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

SECTION 10

#1732790729011

708-423: 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

767-548: Is a circle of latitude that divides a spheroid , such as Earth , into the Northern and Southern hemispheres . On Earth, the Equator is an imaginary line located at 0 degrees latitude , about 40,075 km (24,901 mi) in circumference, halfway between the North and South poles. The term can also be used for any other celestial body that is roughly spherical. In spatial (3D) geometry , as applied in astronomy ,

826-476: 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

885-503: 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

944-421: Is defined as one arc-minute of the Equator, so it has different values depending on which radius is assumed. For example, by WSG-84, the distance is 1,855.3248 metres (6,087.024 ft), while by IAU-2000, it is 1,855.3257 metres (6,087.027 ft). This is a difference of less than one millimetre (0.039 in) over the total distance (approximately 1.86 kilometres or 1.16 miles). Earth is commonly modeled as

1003-419: 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

1062-429: Is tilted towards or away from the sun, resulting in either summer or winter in both hemispheres. This also results in a corresponding movement of the equator away from the subsolar point, which is then situated over or near the relevant tropic circle . Nevertheless, temperatures are high year-round due to the Earth's axial tilt of 23.5° not being enough to create a low minimum midday declination to sufficiently weaken

1121-564: The Apollo Moon landings . The precise location of the Equator is not truly fixed; the true equatorial plane is perpendicular to the Earth's rotation axis , which drifts about 9 metres (30 ft) during a year. Geological samples show that the Equator significantly changed positions between 48 and 12 million years ago, as sediment deposited by ocean thermal currents at the Equator shifted. The deposits by thermal currents are determined by

1180-559: 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

1239-710: 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

SECTION 20

#1732790729011

1298-518: The celestial equator . In the cycle of Earth's seasons , the equatorial plane runs through the Sun twice a year : on the equinoxes in March and September . To a person on Earth, the Sun appears to travel along the equator (or along the celestial equator) at these times. Locations on the equator experience the shortest sunrises and sunsets because the Sun's daily path is nearly perpendicular to

1357-538: The geographical mile . The sea-level surface of Earth (the geoid ) is irregular, so the actual length of the Equator is not so easy to determine. Aviation Week and Space Technology on 9 October 1961 reported that measurements using the Transit IV-A satellite had shown the equatorial diameter from longitude 11° West to 169° East to be 1,000 feet (305 m) greater than its diameter ninety degrees away. Download coordinates as: The Equator passes through

1416-424: The horizon for most of the year. The length of daylight (sunrise to sunset) is almost constant throughout the year; it is about 14 minutes longer than nighttime due to atmospheric refraction and the fact that sunrise begins (or sunset ends) as the upper limb, not the center, of the Sun's disk contacts the horizon. Earth bulges slightly at the Equator; its average diameter is 12,742 km (7,918 mi), but

1475-400: 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

1534-417: 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

1593-444: The Equator (on Earth), noontime sunlight appears almost directly overhead (no more than about 23° from the zenith ) every day, year-round. Consequently, the Equator has a rather stable daytime temperature throughout the year. On the equinoxes (approximately March 20 and September 23) the subsolar point crosses Earth's equator at a shallow angle, sunlight shines perpendicular to Earth's axis of rotation, and all latitudes have nearly

1652-565: The Equator. However, its island of Annobón is 155 km (96 mi) south of the Equator, and the rest of the country lies to the north. France , Norway ( Bouvet Island ), and the United Kingdom are the other three Northern Hemisphere -based countries which have territories in the Southern Hemisphere . Seasons result from the tilt of Earth's axis away from a line perpendicular to the plane of its revolution around

1711-518: The IUGG at its Canberra, Australia meeting of 1979 has an equatorial radius of 6,378.137 km (3,963.191 mi). The WGS 84 (World Geodetic System 1984) which is a standard for use in cartography, geodesy, and satellite navigation including GPS , also has an equatorial radius of 6,378.137 km (3,963.191 mi). For both GRS 80 and WGS 84, this results in a length for the Equator of 40,075.0167 km (24,901.4609 mi). The geographical mile

1770-691: The International Astronomical Union (IAU) use an equatorial radius of 6,378.1366 km (3,963.1903 mi) (codified as the IAU 2009 value). This equatorial radius is also in the 2003 and 2010 IERS Conventions. It is also the equatorial radius used for the IERS 2003 ellipsoid. If it were really circular, the length of the equator would then be exactly 2π times the radius, namely 40,075.0142 km (24,901.4594 mi). The GRS 80 (Geodetic Reference System 1980) as approved and adopted by

1829-513: The Sun's rays even during the solstices. High year-round temperatures extend to about 25° north or south of the equator, although the moderate seasonal temperature difference is defined by the opposing solstices (as it is at higher latitudes) near the poleward limits of this range. Near the equator, there is little temperature change throughout the year, though there may be dramatic differences in rainfall and humidity. The terms summer, autumn, winter and spring do not generally apply. Lowlands around

Black River Gorges National Park - Misplaced Pages Continue

1888-545: The Sun. Throughout the year, the Northern and Southern hemispheres are alternately turned either toward or away from the Sun, depending on Earth's position in its orbit. The hemisphere turned toward the Sun receives more sunlight and is in summer, while the other hemisphere receives less sun and is in winter (see solstice ). At the equinoxes , Earth's axis is perpendicular to the Sun rather than tilted toward or away, meaning that day and night are both about 12 hours long across

1947-477: The afternoon and 23 °C (73 °F) around sunrise. Rainfall is very high away from cold ocean current upwelling zones, from 2,500 to 3,500 mm (100 to 140 in) per year. There are about 200 rainy days per year and average annual sunshine hours are around 2,000. Despite high year-round sea level temperatures, some higher altitudes such as the Andes and Mount Kilimanjaro have glaciers. The highest point on

2006-615: The axis of Earth, which determines solar coverage of Earth's surface . Changes in Earth's axis can also be observed in the geographical layout of volcanic island chains, which are created by shifting hot spots under Earth's crust as the axis and crust move. This is consistent with the Indian tectonic plate colliding with the Eurasian tectonic plate , which is causing the Himalayan uplift. The International Association of Geodesy (IAG) and

2065-464: 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

2124-836: 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

2183-417: 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

2242-649: The diameter at the equator is about 43 km (27 mi) greater than at the poles. Sites near the Equator, such as the Guiana Space Centre in Kourou , French Guiana , are good locations for spaceports as they have the fastest rotational speed of any latitude, 460 m (1,509 ft)/sec. The added velocity reduces the fuel needed to launch spacecraft eastward (in the direction of Earth's rotation) to orbit, while simultaneously avoiding costly maneuvers to flatten inclination during missions such as

2301-632: The equator generally have a tropical rainforest climate , also known as an equatorial climate, though cold ocean currents cause some regions to have tropical monsoon climates with a dry season in the middle of the year, and the Somali Current generated by the Asian monsoon due to continental heating via the high Tibetan Plateau causes Greater Somalia to have an arid climate despite its equatorial location. Average annual temperatures in equatorial lowlands are around 31 °C (88 °F) during

2360-473: The equator is at the elevation of 4,690 metres (15,387 ft), at 0°0′0″N 77°59′31″W  /  0.00000°N 77.99194°W  / 0.00000; -77.99194  ( highest point on the equator ) , found on the southern slopes of Volcán Cayambe [summit 5,790 metres (18,996 ft)] in Ecuador . This is slightly above the snow line and is the only place on the equator where snow lies on

2419-431: The equator of a rotating spheroid (such as a planet ) is the parallel (circle of latitude) at which latitude is defined to be 0°. It is an imaginary line on the spheroid, equidistant from its poles , dividing it into northern and southern hemispheres. In other words, it is the intersection of the spheroid with the plane perpendicular to its axis of rotation and midway between its geographical poles . On and near

Black River Gorges National Park - Misplaced Pages Continue

2478-422: 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

2537-473: 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

2596-477: 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

2655-514: 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

2714-441: 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

2773-625: The land of eleven sovereign states . Indonesia is the country straddling the greatest length of the equatorial line across both land and sea. Starting at the Prime Meridian and heading eastwards, the Equator passes through: The Equator also passes through the territorial seas of three countries: Maldives (south of Gaafu Dhaalu Atoll ), Kiribati (south of Buariki Island ), and the United States (south of Baker Island ). Despite its name, no part of Equatorial Guinea lies on

2832-437: 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

2891-586: The other four are the two polar circles (the Arctic Circle and the Antarctic Circle ) and the two tropical circles (the Tropic of Cancer and the Tropic of Capricorn ). The equator is the only line of latitude which is also a great circle —meaning, one whose plane passes through the center of the globe. The plane of Earth's equator, when projected outwards to the celestial sphere , defines

2950-473: 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

3009-708: 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

SECTION 50

#1732790729011

3068-420: 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 ,

3127-581: 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

3186-482: 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

3245-421: 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

3304-443: 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

3363-433: 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

3422-445: The whole of Earth. Near the equator, this means the variation in the strength of solar radiation is different relative to the time of year than it is at higher latitudes: maximum solar radiation is received during the equinoxes, when a place at the equator is under the subsolar point at high noon, and the intermediate seasons of spring and autumn occur at higher latitudes; and the minimum occurs during both solstices, when either pole

3481-749: 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

#10989