Amazon basin: Difference between revisions

[[File:Mouths of amazon geocover 1990.png|thumb|The mouth of the [[Amazon River]], the [[List of rivers by length|second longest]]<ref>{{cite web | url=http://news.nationalgeographic.com/news/2007/06/070619-amazon-river.html | title=Amazon Longer Than Nile River, Scientists Say | publisher=National Geographic | date=18 June 2007 | author=Roach, John}}</ref> river in the world.]]

The '''Amazon Basin''' is the part of [[South America]] drained by the [[Amazon River]] and its tributaries that drains an area of about {{convert|6,915,000|km2|sqmi|abbr=on}}, or roughly 40 percent of South America. The [[Drainage basin|basin]] is located in the countries of [[Bolivia]], [[Brazil]], [[Colombia]], [[Ecuador]], [[Guyana]], [[Peru]], [[Suriname]] and [[Venezuela]].<ref>Goulding, M., Barthem, R. B. and Duenas, R. (2003). ''The Smithsonian Atlas of the Amazon'', Smithsonian Books ISBN 1588341356</ref>

==Plant life==

As much of the Amazon is unexplored, many of its indigenous plants and animals are unknown. Plant growth is dense and its variety of animals inhabitants is comparatively high due to the heavy rainfall and the dense and extensive [[Evergreen forest|evergreen]] and [[coniferous forest]]s. The sunlight can not reach the ground because of the dense roof created by plants. The ground remains dark and damp and only shade tolerant trees and vegetation will grow here. [[Orchid]]s and [[bromeliad]]s exploit trees and other plants to get closer to the sunlight. They grow hanging onto the branches or tree trunks with [[aerial roots]], not as parasites but as [[epiphyte]]s. One tropical fruit tree that is native to the Amazon is the [[abiu]]. The Amazon Basin contains thousands of plant species. The bromeliads are special in that they hold water, and frogs may use these plants to hatch their eggs, besides many other living organisms that have their homes in them.The Kapok Tree is the biggest tree of the Amazon rainforest, as it can grow to 200 feet tall and the trunk can be 10 or 11 feet in diameter.

==Animal life==

More than 14,000 species of mammal are found in the Amazon, the majority of which are bats and rodents. Its larger mammals include the [[jaguar]], [[ocelot]], [[capybara]] and [[tapir]].

About 1500 bird species inhabit the Amazon Basin.<ref>Butler, Rhett A. (9 January 2006) [http://rainforests.mongabay.com/0305.htm “Diversities of Image – Rainforest Biodiversity.”] Mongabay.com.</ref> The biodiversity of the Amazon and the sheer number of diverse bird species is given by the number of different bird families that reside in these humid forests. An example of such would be the [[cotinga]] family, to which the [[Guianan Cock-of-the-rock]] belong. Birds such as [[toucan]]s, and [[hummingbird]]s are also found here. [[Macaw]]s are famous for gathering by the hundreds along the clay cliffs of the Amazon River. In the western Amazon hundreds of macaws and other parrots descend to exposed river banks to consume clay on an almost daily basis,<ref>Munn, C. A. 1994. Macaws: winged rainbows. National Geographic, 185, 118-140.</ref> the exception being rainy days.<ref>Brightsmith, D. J. 2004. Effects of weather on parrot geophagy in Tambopata, Peru. Wilson Bulletin, 116, 134-145.</ref>

The world's largest snake, the [[anaconda]], inhabits the shallow waters of the Amazon and the [[Emerald tree boa]] and [[boa constrictor]] live in the Amazonian tree tops. Also the [[basilisk lizard]] lives in the Amazon Basin.

With more than 2,200 species the Amazon Basin has a larger fish fauna than any other river basin on Earth, and Amazonia is the center of diversity for [[Neotropical fishes]].<ref name="AlbertReis2011">{{cite book|author1=James S. Albert|author2=Roberto E. Reis|title=Historical Biogeography of Neotropical Freshwater Fishes|url=http://books.google.com/books?id=_Suu7a-ERdMC&pg=PA308|accessdate=28 June 2011|date=8 March 2011|isbn=9780520268685|page=308}}</ref> The Amazon Basin is home to the [[red-bellied piranha]], an omnivorous forager that encompasses a larger geographic area than any other piranha species. The remarkable species richness can in part be explained by the large differences between the various parts of the Amazon Basin, resulting in many fish species that are [[Endemism|endemic]] to small regions. For example, fauna in clearwater rivers differ from fauna in [[blackwater river]]s, fauna in slow moving sections show distinct differences compared to that in [[rapid]]s, fauna in small streams differ from that in major rivers, and fauna in shallow sections show distinct differences compared to that in deep parts.<ref>Stewart, D. J., M. Ibarra, and R.. Barriga-Salazar (2002). ''Comparison of Deep-River and Adjacent Sandy-Beach Fish Assemblages in the Napo River Basin, Eastern Ecuador. Copeia 2002(2): 333-343''</ref><ref>Mendonça, F. P., W. E. Magnusson, J. Zuanon and C. M. Taylor. (2005) ''Relationships between habitat characteristics and fish assemblages in small streams of Central Amazonia.'' Copeia 2005(4): 751-764</ref>

Over 90% of the animal species in the Amazon are [[insect]]s,{{Citation needed|reason=Reliable source needed|date=January 2014}} of which about 40% are [[beetle]]s (Coleoptera constituting almost 25% of all known types of animal life-forms<ref name=insenc>[[#refPowell|Powell (2009)]]</ref><ref>{{Cite book|title=Species Diversity in Space and Time|author=Rosenzweig, Michael L. |publisher=Cambridge University Press|isbn=9780521499521|year=1995}}</ref><ref>{{cite journal |author=Hunt, T. et al. |title=A Comprehensive Phylogeny of Beetles Reveals the Evolutionary Origins of a Superradiation |journal=Science |volume=318 |issue=5858 |pages=1913–1916 |year=2007 |pmid=18096805 |doi=10.1126/science.1146954 |bibcode = 2007Sci...318.1913H }}</ref>).

==Climate and seasons==

The [[Amazon River]] Basin has low-water season, and a wet season during which the rivers [[flood]] adjacent low lying forests. The climate of the basin is generally hot and humid. In some areas, however, the winter months (June–September) can bring cold snaps, fueled by Antarctic winds travelling along the adjacent Andes mountain range. Such cold conditions can be devastating for some of the region's tropical plant and animal species.<ref>{{cite journal|doi=10.1038/news.2010.437|title=Cold empties Bolivian rivers of fish|year=2010|last1=Petherick|first1=Anna|journal=Nature}}</ref>

==Human occupation==

==River commerce==

==Sustainable opportunistic agriculture in undeveloped areas==

==Non-sustainable agriculture in developed areas==

==Geography==

The Amazon Basin is bounded by the [[Guiana Highlands]] to the north and the [[Brazilian Highlands]] to the south. The Amazon, which rises in the [[Andes]] Mountains at the west of the basin, is the second longest river in the world. It covers about 6,400&nbsp;km before draining into the [[Atlantic Ocean]]. The Amazon and its tributaries form the largest volume of water. The Amazon accounts for about 20% of the total water carried to the oceans by rivers. Some of the [[Amazon Rainforest]] is [[Deforestation|deforested]] because of a growing interest in hardwood products.

The highest point in the watershed of the Amazon is the peak of [[Yerupajá]] at 6,635 m (21,768&nbsp;ft).

Politically the basin is divided into the Brazilian [[Amazônia Legal]], the [[Peruvian Amazon]], the [[Amazon Region of Colombia]] and parts of [[Bolivia]], [[Ecuador]] and the Venezuelan state of [[Amazonas (Venezuelan state)|Amazonas]].

==Languages==

==See also==

==References==

==Further reading==

==External links==