Amazon rainforest
The Amazon rainforest, also called the Amazon jungle or Amazonia, is a moist broadleaf tropical rainforest in the Amazon biome that covers most of the Amazon basin of South America. This basin encompasses, of which are covered by the rainforest. This region includes territory belonging to nine nations and 3,344 indigenous territories.
The majority of the forest, 60%, is in Brazil, followed by Peru with 13%, Colombia with 10%, and with minor amounts in Bolivia, Ecuador, French Guiana, Guyana, Suriname, and Venezuela. Four nations have "Amazonas" as the name of one of their first-level administrative regions, and France uses the name "Guiana Amazonian Park" for French Guiana's protected rainforest area. The Amazon represents over half of the total area of remaining rainforests on Earth, and comprises the largest and most biodiverse tract of tropical rainforest in the world, with an estimated 390 billion individual trees in about 16,000 species.
More than 30 million people of 350 different ethnic groups live in the Amazon, which are subdivided into 9 different national political systems and 3,344 formally acknowledged indigenous territories. Indigenous peoples make up 9% of the total population, and 60 groups remain largely isolated.
Large scale deforestation is occurring in the forest, creating different harmful effects. Economic losses due to deforestation in Brazil could be approximately 7 times higher in comparison to the cost of all commodities produced through deforestation. In 2023, the World Bank published a report proposing a non-deforestation based economic program in the region. Deforestation hurts agriculture so severely that it can lead to "agro-suicide."
Etymology
The name Amazon is said to arise from a war Francisco de Orellana fought with the Tapuyas and other tribes. The women of the tribe fought alongside the men, as was their custom. Orellana derived the name Amazonas from the Amazons of Greek mythology, described by Herodotus and Diodorus.History
Based on archaeological evidence from an excavation at Caverna da Pedra Pintada, human inhabitants first settled in the Amazon region at least 11,200 years ago. Subsequent development led to late-prehistoric settlements along the periphery of the forest by AD 1250, which induced alterations in the forest cover.For a long time, it was thought that the Amazon rainforest was never more than sparsely populated, as it was impossible to sustain a large population through agriculture given the poor soil. Archeologist Betty Meggers was a prominent proponent of this idea, as described in her book Amazonia: Man and Culture in a Counterfeit Paradise. She claimed that a population density of is the maximum that can be sustained in the rainforest through hunting, with agriculture needed to host a larger population. However, recent anthropological findings have suggested that the region was actually densely populated. The Upano Valley sites in present-day eastern Ecuador predate all known complex Amazonian societies.
Some 5 million people may have lived in the Amazon region in AD 1500, divided between dense coastal settlements, such as that at Marajó, and inland dwellers. Based on projections of food production, one estimate suggests over 8 million people living in the Amazon in 1492. By 1900, the native indigenous population had fallen to 1 million and by the early 1980s it was less than 200,000.
The first European to travel the length of the Amazon River was Francisco de Orellana in 1542. The BBC's Unnatural Histories presents evidence that Orellana, rather than exaggerating his claims as previously thought, was correct in his observations that a complex civilization was flourishing along the Amazon in the 1540s. The Pre-Columbian agriculture in the Amazon Basin was sufficiently advanced to support prosperous and populous societies. It is believed that civilization was later devastated by the spread of diseases from Europe, such as smallpox. This civilization was investigated by the British explorer Percy Fawcett in the early twentieth century. The results of his expeditions were inconclusive, and he disappeared mysteriously on his last trip. His name for this lost civilization was the City of Z.
Since the 1970s, numerous geoglyphs have been discovered on deforested land dating between AD 1–1250, furthering claims about Pre-Columbian civilizations. Ondemar Dias is accredited with first discovering the geoglyphs in 1977, and Alceu Ranzi is credited with furthering their discovery after flying over Acre. The BBC's Unnatural Histories presented evidence that the Amazon rainforest, rather than being a pristine wilderness, has been shaped by man for at least 11,000 years through practices such as forest gardening and terra preta. Terra preta is found over large areas in the Amazon forest; and is now widely accepted as a product of indigenous soil management. The development of this fertile soil allowed agriculture and silviculture in the previously hostile environment; meaning that large portions of the Amazon rainforest are probably the result of centuries of human management, rather than naturally occurring as has previously been supposed. In the region of the Xingu tribe, remains of some of these large settlements in the middle of the Amazon forest were found in 2003 by Michael Heckenberger and colleagues of the University of Florida. Among those were evidence of roads, bridges and large plazas.
In the Amazonas, there has been fighting and wars between the neighboring tribes of the Jivaro. Several tribes of the Jivaroan group, including the Shuar, practised headhunting for trophies and headshrinking. The accounts of missionaries to the area in the borderlands between Brazil and Venezuela have recounted constant infighting in the Yanomami tribes. More than a third of the Yanomamo males, on average, died from warfare.
The Munduruku were a warlike tribe that expanded along the Tapajós river and its tributaries and were feared by neighboring tribes. In the early 19th century, the Munduruku were pacified and subjugated by the Brazilians. It is documented that large war parties of the Bororo, Kayapo, Munduruku, Guaraní, and Tupi people carried out long-distance raids. Most Bororo groups were continually at war with their neighbors. In contrast, the Xingu have been described by ethnographers as a "peaceful" society, resorting to violence only in defense against their warlike neighbors. In the early 20th century, thirty indigenous tribes in the Amazon basin were listed as "peaceful" and eighty-three were specifically described as "warlike".
During the Amazon rubber boom it is estimated that diseases brought by immigrants, such as typhus and malaria, killed 40,000 native Amazonians.
In the 1950s, Brazilian explorer and defender of indigenous people, Cândido Rondon, supported the Villas-Bôas brothers' campaign, which faced strong opposition from the government and the ranchers of Mato Grosso and led to the establishment of the first Brazilian National Park for indigenous people along the Xingu River in 1961.
In 1961, British explorer Richard Mason was killed by an uncontacted Amazon tribe known as the Panará.
The Matsés made their first permanent contact with the outside world in 1969. Before that date, they were effectively at-war with the Peruvian government.
Geography
Location
Nine countries share the Amazon basin—most of the rainforest, 58.4%, is contained within the borders of Brazil. The other eight countries are Peru with 12.8%, Bolivia with 7.7%, Colombia with 7.1%, Venezuela with 6.1%, Guyana with 3.1%, Suriname with 2.5%, French Guiana with 1.4% and Ecuador with 1%.Natural
The rainforest likely formed during the Eocene era. It appeared following a global reduction of tropical temperatures when the Atlantic Ocean had widened sufficiently to provide a warm, moist climate to the Amazon basin. The rainforest has been in existence for at least 55 million years, and most of the region remained free of savanna-type biomes at least until the current ice age when the climate was drier and savanna more widespread.Following the Cretaceous–Paleogene extinction event, the extinction of the dinosaurs and the wetter climate may have allowed the tropical rainforest to spread out across the continent. From 66 to 34 Mya, the rainforest extended as far south as 45°. Climate fluctuations during the last 34 million years have allowed savanna regions to expand into the tropics. During the Oligocene, for example, the rainforest spanned a relatively narrow band. It expanded again during the Middle Miocene, then retracted to a mostly inland formation at the last glacial maximum. However, the rainforest still managed to thrive during these glacial periods, allowing for the survival and evolution of a broad diversity of species.
During the mid-Eocene, it is believed that the drainage basin of the Amazon was split along the middle of the continent by the Purus Arch. Water on the eastern side flowed toward the Atlantic, while to the west water flowed toward the Pacific across the Amazonas Basin. As the Andes Mountains rose, however, a large basin was created that enclosed a lake; now known as the Solimões Basin. Within the last 5–10 million years, this accumulating water broke through the Purus Arch, joining the easterly flow 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 and subsequent deglaciation. Analyses of sediment deposits from Amazon basin paleolakes and the Amazon Fan indicate that rainfall in the basin during the LGM was lower than for the present, and this was almost certainly associated with reduced moist tropical vegetation cover in the basin. In present day, the Amazon receives approximately 9 feet of rainfall annually. There is a debate, however, over how extensive this reduction was. Some scientists argue that the rainforest was reduced to small, isolated refugia separated by open forest and grassland; other scientists argue that the rainforest remained largely intact but extended less far to the north, south, and east than is seen today. This debate has proved difficult to resolve because the practical limitations of working in the rainforest mean that data sampling is biased away from the center of the Amazon basin, and both explanations are reasonably well supported by the available data.