The Amazon rainforest (Portuguese: Floresta AmazÃÆ'Â'nica or AmazÃÆ'Â'nia ; Spanish: Selva AmazÃÆ'³nica , AmazonÃÆ'a or usually Amazonia ; French: ForÃÆ'ªt amazonienne ; Dutch: Amazoneregenwoud ), also known in English as Amazonia or Amazon Jungle , is a moist wide-leaved forest in the Amazonian biome that covers most of the Amazon Basin of South America. This basin covers 7,000,000 km 2 (2,700,000 sqÃ, mi), of which 5.500.000 km 2 (2,100,000 sq. N, mi) is covered by rain forests. This region belongs to nine countries. The majority of the forest is contained in Brazil, with 60% of the rainforest, followed by Peru with 13%, Colombia with 10%, and small amounts in Venezuela, Ecuador, Bolivia, Guyana, Suriname and French Guiana. Countries or departments in four countries contain "Amazonas" in their name. The Amazon represents more than half the remaining rainforest on the planet, and consists of the largest and most diverse tropical rainforest in the world, with an estimated 390 billion individual trees split into 16,000 species.
Video Amazon rainforest
Etymology
The name Amazon is said to have originated from the Francisco de Orellana war that fought the Tapuyas and others. The women of the tribe fought with men, as was their custom. Orellana got the name Amazonas from Amazon Greek mythology, described by Herodotus and Diodorus.
Maps Amazon rainforest
History
Natural
Rainforests are likely to form during the Eocene era. It appears following a global reduction in tropical temperatures when the Atlantic Ocean has widened sufficiently to provide a warm and humid climate to the Amazon basin. Rainforests have been around for at least 55 million years, and most areas remain free of savanna biomes at least until the current ice age, when the climate is drier and the savannas are wider.
After the Cretaceous-Paleogene extinction event, the extinction of dinosaurs and wet climates may have allowed tropical rain forests to spread throughout the continent. From 66-34 Mya, rainforests extended as far south as 45 °. Climate fluctuations over the past 34 million years have allowed savanna regions to flourish into the tropics. During the Oligocene, for example, the rain forest stretched a relatively narrow band. It expanded again during the Middle Miocene, then retracted to most land formations at its last glacial maximum. However, the rainforest still managed to thrive during this glacial period, allowing for the survival and evolution of vast species diversity.
During the middle of the Eocene, it was believed that the Amazon drainage valley was split in the middle of the continent by Purus Arch. Water on the eastern side flows into the Atlantic, while to the west the water flows into the Pacific along the Amazonas Basin. When the Andes Mountains rise, however, a large basin is created that is covered in lakes; now known as SolimÃÆ'Âμes Basin. In the last 5-10 million years, this accumulated water penetrates Arch Purus, joining the eastern stream toward the Atlantic.
There is evidence that there have been significant changes in the Amazon rainforest vegetation over the last 21,000 years through the Last Glacial Maximum (LGM) and subsequent deglaciation. Analysis of sedimentary sediments from the paleolakes of the Amazon basin and from the Amazon Fan shows that rainfall in the basin during LGM is lower than it is today, and this is almost certainly associated with reduced wet tropical vegetation cover in the basin. However, there is a debate about how widespread this reduction is. Some scientists argue that the rainforest is reduced to an isolated, small refuge separated by open forest and grassland; other scientists argue that the rainforest is largely intact but not too far north, south, and east than is seen today. This debate has proven difficult to resolve because of the practical limitations of working in the rainforest means that the sampling of data is far from the center of the Amazon basin, and both of these descriptions are adequately supported by the available data.
Sahara Desert blown off to the Amazon
More than 56% of Amazon rainforest dust comes from the depression of Bodà © in Northern Chad in the Sahara desert. Dust contains phosphorus, essential for plant growth. Annual Sahara dust replaces the same amount of phosphorus that is carried annually on the Amazonian soil from rain and floods. Up to 50 million tons of Sahara dust per year blown in the Atlantic Ocean. NASA Videos .
The NASA CALIPSO satellite measured the amount of dust transported by the wind from the Sahara to the Amazon: an average of 182 million tonnes of dust blown off the Sahara every year, at 15 degrees west longitude, 1,600 miles (2,600 km) above the Atlantic dust fell to the Atlantic), then at 35 degrees west longitude on the east coast of South America, 27.7 million tons (15%) of the dust fell over the Amazon basin, 132 million tons of dust remained in the air, 43 million tons of wind-blown dust and crashed in the Caribbean Sea, past 75 degrees west longitude.
CALIPSO uses laser range search to scan Earth's atmosphere for vertical distribution of dust and other aerosols. CALIPSO regularly tracks clusters of Sahara-Amazon dust. CALIPSO has measured the variation in the amount of dust transported - an 86 percent drop between the highest amount of dust transported in 2007 and the lowest in 2011.
The possible cause of the variation is Sahel, a semi-arid plot of land on the southern border of the Sahara. When the amount of rain in the Sahel is higher, the volume of dust is lower. Higher rainfall can make more vegetation grow in the Sahel, leaving less sand exposed to the wind to blow.
Human activity
Based on archaeological evidence from excavations at the Caverna da Pedra Pintada, human inhabitants first settled in the Amazon region at least 11,200 years ago. Subsequent developments led to the final prehistoric settlement along the edge of the forest in 1250, which led to changes in forest cover.
For a long time, it is estimated that the Amazon rainforest is only sparsely populated, as it is impossible to sustain large populations through agriculture due to poor soils. Archaeologist Betty Meggers is a major proponent of this idea, as described in his book Amazonia: Man and Culture in the False Heaven . He claims that 0.2 population density per square kilometer (0.52/sq./mi) is the maximum that can be maintained in the rainforest through hunting, with agriculture necessary to accommodate larger populations. However, recent anthropological findings indicate that the region is in fact densely populated. Approximately 5 million people may live in the Amazon region in 1500 AD, divided between dense coastal settlements, such as in MarajÃÆ'³, and inland populations. By 1900, the population had fallen to 1 million and by the early 1980s the number was less than 200,000.
The first European to travel along the Amazon River was Francisco de Orellana in 1542. The BBC's Unicorn Natural History presents evidence that Orellana, rather than exaggerating his claim as expected, is true in his observation that civilization the complex developed along the Amazon in the 1540s. It is believed that the civilization was later destroyed by the spread of disease from Europe, such as smallpox.
Since the 1970s, many geoglyphs have been discovered on the date of deforested land between AD 1-1250, further claims about the Pre-Columbian civilization. Ondemar Dias was accredited with first discovering geoglyph in 1977 and Alceu Ranzi by advancing their discovery after flying over Acre. The BBC's Unicorn History provides evidence that the Amazon rainforest, rather than pure wilderness, has been shaped by humans for at least 11,000 years through practices such as forest gardening and terra preta â € <â € . Terra preta is found in large areas of the Amazon jungle; and is now widely accepted as a product of indigenous soil management. The development of fertile soils allows agriculture and silviculture in previously unfriendly environments; meaning that most of the Amazon rainforest may be the result of centuries of human management, not naturally as has been previously thought. In the Xingu region, the remains of some of these large settlements in the middle of the Amazon forest were discovered in 2003 by Michael Heckenberger and colleagues from the University of Florida. Among them is evidence of roads, bridges and large plazas.
Biodiversity
Wet tropical forests are the species richest biomes, and tropical forests in the Americas are consistently more species-rich than wet forests in Africa and Asia. As the largest rainforest channel in America, the Amazon rainforest has an unparalleled biodiversity. One of ten known species in the world lives in the Amazon rainforest. It is the largest collection of living plants and animal species in the world.
This region has about 2.5 million species of insects, tens of thousands of plants, and about 2,000 birds and mammals. To date, at least 40,000 plant species, 2,200 fish, 1,294 birds, 427 mammals, 428 amphibians, and 378 reptiles have been scientifically classified in the region. One in five bird species is found in the Amazon rainforest, and one in five fish species live in Amazon rivers and rivers. Scientists have described between 96,660 and 128,843 species of invertebrates in Brazil alone.
The diversity of plant species is the highest on Earth with a 2001 study finding a quarter of a square kilometer (62 hectares) of Ecuadorian rainforests supporting more than 1,100 species of trees. A study in 1999 found a square kilometer (247 hectares) of the Amazon rainforest can contain about 90,790 tons of live plants. The average plant biomass is estimated at 356 Ã, Â ± 47 tons per hectare. To date, an estimated 438,000 species of economic and social flowering plants have been registered in the region with much more to discover or catalog. The total number of tree species in the region is estimated at 16,000.
The area of ​​green leaves of plants and trees in the rainforest varies about 25% as a result of seasonal changes. Leaves expands during the dry season when maximum sunlight, then absent in the rainy season is overcast. This change provides a carbon balance between photosynthesis and respiration.
Rainforests contain several species that can cause hazards. Among the largest predator creatures are black caiman, jaguar, cougar, and anaconda. In rivers, electric eels can produce electric shocks that can sting or kill, while the piranha are known to bite and injure humans. Various species of poison dart frogs secrete lipophilic alkaloid toxins through their flesh. There are also many parasites and disease vectors. Vampire bats live in the rainforest and can spread the rabies virus. Malaria, yellow fever and dengue can also be contracted in the Amazon region.
Deforestation
Deforestation is the conversion of forest areas into non-forest areas. The main sources of deforestation in the Amazon are human settlements and land development. Before the early 1960s, access to the interior of the forest was limited, and the forest was still intact. The farms established during the 1960s were based on cultivation of crops and slash and burn methods. However, the colonists can not manage their fields and crops because of the loss of soil fertility and weed invasion. Land in the Amazon is only productive for a short time, so farmers keep moving to new areas and clearing more land. These agricultural practices cause deforestation and cause extensive environmental damage. Deforestation is considerable, and the forest cleared area is visible to the naked eye from outer space.
In the 1970s construction began on the Trans-Amazonian highway. This highway represents a major threat to the Amazon rainforest. Fortunately for the rainforest, the highway has not been completed, with this reduces the environmental damage.
Between 1991 and 2000, the total area of ​​forest lost in the Amazon rose from 415,000 to 587,000 square kilometers (160,000 to 227,000 sq. N, mi), with most of the forest lost to pasture for livestock. Seventy percent of the land that used to be forests in the Amazon, and 91 percent of deforested land since 1970, is used for cattle grazing. Currently, Brazil is the second largest soybean producer in the world after the United States. However, new research conducted by Leydimere Oliveira et al., Has shown that the more rainforests being felled in the Amazon, the less rainfall reaches the area and the lower the yield per hectare. So despite popular perceptions, there is no economic benefit to Brazil from deforestation and turning it into a pastoral field.
The need for soybean farmers has been used to justify many of the controversial transportation projects currently under development in the Amazon. The first two highways were able to clear rain forests and lead to increased settlements and deforestation. The average annual deforestation rate from 2000 to 2005 (22,392 km 2 or 8,646 sqa, mi per year) was 18% higher than in the previous five years (19.018 km 2 or 7,343 sqÃ, noodles per year). Although deforestation has declined significantly in the Brazilian Amazon between 2004 and 2014, there has been an increase to this day.
Conservation and climate change
Environmentalists are concerned about the loss of biodiversity that will result from forest destruction, as well as the release of carbon contained in vegetation, which can accelerate global warming. The Amazon pine forest accounts for about 10% of the world's terrestrial primary productivity and 10% of carbon stores in ecosystems - from the order of 1.1Ã, ÃÆ'â € "10 11 carbon metric tons. The Amazon forest is estimated to have accumulated 0.62 Â ± 0.37 tons of carbon per hectare per year between 1975 and 1996.
One computer model of future climate change caused by greenhouse gas emissions suggests that the Amazon rainforest can become unsustainable under conditions of very reduced rainfall and rising temperatures, which leads to the almost complete loss of rainforest cover in the basin in the year 2100. However, Amazon simulations of basin climate change in many different models are inconsistent in their estimates of the rainfall response, ranging from a weak increase to a strong decline. The results show that rainforests can be threatened even though the 21st century by climate change in addition to deforestation.
In 1989, environmental activist C.M. Peters and two colleagues state there are economic and biological incentives to protect the rainforest. One hectare in Peruvian Amazon has been calculated to have a value of $ 6820 if intact forests are harvested sustainably for fruit, latex, and wood; $ 1000 if clearcut for commercial timber (not harvested sustainably); or $ 148 if used as cattle pasture.
As indigenous territories continue to be destroyed by deforestation and ecosides, as in the rainforest communities the indigenous Amazon indigenous people continue to disappear, while others, such as Urarina continue to struggle to fight for their cultural viability and the fate of their forest territory. Meanwhile, the relationship between non-human primates in the subsistence and symbolism of the indigenous lowlands of South America has received increasing attention, as is the conservation effort of ethno-biology and community-based conservation.
From 2002 to 2006, conserved land in the Amazon rainforest has nearly tripled and the rate of deforestation has fallen by 60%. Approximately 1,000,000 square kilometers (250,000,000 hectares) have been incorporated into a kind of conservation, which adds up to the current 1,730,000 square kilometers (430,000,000 hectares).
A 2009 study found that rising temperatures of 4 Â ° C in global temperatures by 2100 would kill 85% of the Amazon rainforest while a rise in temperature of 3 Â ° C would kill about 75% of Amazon.
Remote sensing
The use of remote sensing data dramatically increases the conservationist's knowledge of the Amazon basin. Given the objectivity and lower cost of satellite-based land cover analysis, it seems that remote sensing technology will be an integral part of the assessment of the rate and damage of deforestation in the basin. Furthermore, remote sensing is the best and probably only possible way to learn about Amazon on a large scale.
The use of remote sensing for Amazon conservation is also used by indigenous tribes from river basins to protect their tribal lands from commercial interests. Using handheld GPS devices and programs like Google Earth, members of the Trio Tribe, who live in the rainforests of southern Suriname, chart their ancestral lands to help strengthen their territorial claims. Today, most tribes in the Amazon do not have clear boundaries, making it easier for commercial businesses to target their territory.
To accurately map Amazon's biomass and subsequent carbon emissions, the classification of tree growth stages in different parts of the forest is essential. In 2006 Tatiana Kuplich arranged the Amazon trees into four categories: (1) adult forest, (2) regeneration forest [less than three years], (3) forest regeneration [between three and five years of regrowth], and (4) )) forest regeneration [eleven to eighteen years of sustainable development]. Researchers used a combination of Synthetic aperture radar (SAR) and Thematic Mapper (TM) to place different parts of the Amazon into one of four classifications.
The impact of the early 21st century Amazon drought
In 2005, parts of the Amazon basin suffered the worst drought in a hundred years, and there are indications that 2006 could be the second consecutive year of drought. A July 23, 2006 article in the British newspaper The Independent reported the results of the Woods Hole Research Center which shows that the forest in its present form can only survive for three years of drought. Scientists at Brazil's National Amazonian Research Institute denied in an article that this drought response, coupled with the effects of deforestation on regional climates, pushed the rainforest toward a "tipping point" where it would die irreversibly. It concludes that forests are on the edge of turning into savannahs or deserts, with disastrous consequences for the world's climate.
According to the World Wide Fund for Nature, the combination of climate change and deforestation increases the drying effect of dead trees that trigger forest fires.
In 2010 the Amazon rainforest suffered a severe drought, in some ways more extreme than the dry season of 2005. The affected area is an estimated 1,160,000 square miles (3,000,000 km 2 ) of rainforest, compared to 734,000 square miles (1.9 million km2 2 ) in 2005. The 2010 drought has three epicenters where vegetation dies, while in 2005 the drought focused on the southwest. The findings were published in the journal Science. In a typical year, the Amazon absorbs 1.5 gigatonnes of carbon dioxide; during 2005 instead of 5 gigatons released and in 2010 8 gigatons was released. Additional severe droughts occurred in 2010, 2015, and 2016.
See also
References
Further reading
- Sheil, D.; Wunder, S. (2002). "The value of tropical forests for local communities: complications, warnings and warnings". Conservation Ecology . 6 (2): 9.
- "Deforestation." World Geography. Columbus, Ohio: McGraw-Hill/Glencoe, 2000. 202-204
- Wade, Lizzie. (2015). "Drones and satellites where civilizations are lost in places that are impossible." Science (American Association for the Advancement of Science), doi: 10.1126/science.aaa7864
External links
Media related to Amazon Rainforest on Wikimedia Commons
- Journey To Amazonia
- Amazon: The Greatest Rainforest in the World
- WWF in the Amazon rainforest
- Amazonia.org.br Daily updated Amazon daily information database on the web, hosted by Friends of The Earth - Brazilian Amazon.
- amazonia.org Sustainable Development at Baixo Rio Branco Extractive Reserve - Rio Jauaperi - Brazilian Amazon.
- Amazon Rainforest News Genuine news update on Amazon.
- Amazon-Rainforest.org Information about the Amazon rainforest, its people, places of interest, and how everyone can help.
- Conference: Climate change and Amazon's fate. Podcast talks are given at Oriel College, University of Oxford, 20-22 March 2007.
Source of the article : Wikipedia
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