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[[File:River in the Amazon rainforest.jpg|thumb|right|250px|[[Amazon river]] rain forest in [[Brazil]]]]

A '''tropical rainforest''' is a [[rainforest]] with [[tropical]] [[animal]]s and [[plant]]s. They are found in a band around the [[equator]] and cover 6% of the [[Earth]]'s surface. They are [[warm]] for most of the year but have a lot of [[rainfall]]. They also have many different plants and animals. 
The tropical rainforest is a [[biome]]. The biggest tropical rainforest is mostly in [[Brazil]]. Other rainforests are in Asia ([[Indonesia]] mainly), central [[Africa]] and north eastern [[Australia]]. A tropical rainforest gets over 274 cm of rainfall every year.

== Characteristics ==
The characteristics of this type are forest are: <ref name=Burnham/>

#Land is mostly under 700 metres down to below sea level
#Climate:
##High rainfall
##High temperature
##Equable: not much variation
#Vegetation: 90% or more Angiosperms
##Tall canopy trees
##[[Liana]]s ([[climbing plants]])
##[[Epiphyte]]s
##Leaves large, complete margins, with drip tips
##Flowers and fruits large
##[[Pollination]] mainly by insects
##[[Leguminaceae]] are the most common plant family
##[[Evergreen]]s: leaves may be shed, but not seasonally
#Animals
##High diversity: many different species
##Many insects which eat plants, and many [[Defence against herbivory|anti-insect defences by plants]]
##Many [[arboreal]] (tree-living) mammals

== History ==
[[File:Campo12Foto 2.JPG|thumb|250px|The [[Amazon rainforest]] taken from plane]]

There is more known of the history of the Amazonian rainforest than any other. The rainforest likely formed during the [[Eocene]] era. Flowering plants are first seen in the [[Lower Cretaceous]], and they radiated in the [[Upper Cretaceous]]. The evolution of the large forest canopy trees came right at the end of the Cretaceous, when trees like [[beech]], [[oak]], [[maple]], and [[magnolia]] are seen.<ref name="SadavaHeller2006">{{cite book|author1=David Sadava|author2=H. Craig Heller|author3=Gordon H. Orians|coauthors=William K. Purves, David M. Hillis|title=Life: the science of biology|url=http://books.google.com/books?id=1m0_FLEjd-cC&pg=PA477|accessdate=4 August 2010|date=December 2006|publisher=Macmillan|isbn=978-0-7167-7674-1|pages=477–}}</ref> The [[herbaceous]] Angiosperms appear even later.<ref>{{cite book |first=Wilson Nichols |last=Stewart |first2=Gar W. |last2=Rothwell |title=Paleobotany and the evolution of plants |edition=2nd |publisher=Cambridge Univ. Press |year=1993 |page=498 |isbn=0-521-23315-1 }}</ref> 

The rain forest has been in existence for at least 55 million years, and most of the region remained free of [[savanna]]-type [[biome]]s at least until the [[Pleistocene]] [[ice age]], when the climate was drier and savanna more widespread.<ref name=morley>{{cite book
 | first=Robert J. | last=Morley | year=2000
 | title=Origin and evolution of tropical rain forests
 | publisher=Wiley | isbn=0-471-98326-8
}}</ref><ref name=Burnham>{{cite journal
 | last=Burnham | first=Robyn J.
 | coauthors=Johnson, Kirk R.
 | title=South American palaeobotany and the origins of neotropical rainforests
 | journal=Philosophical Transactions of the Royal Society
 | year=2004 | volume=359 | issue=1450
 | pmid=15519975
 | pmc=1693437
 | pages=1595–1610 | doi=10.1098/rstb.2004.1531 }}</ref>

Following the [[Cretaceous–Paleogene extinction event]], the extinction of the [[dinosaur]]s and the wetter climate may have allowed the tropical rainforest to spread out across the continent. From 65–34&nbsp;mya, the rainforest extended as far south as 45° south. 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 that lay mostly above 15° north. It expanded again during the [[Miocene]], then retracted to a mostly inland formation at the last glacial maximum (roughly 25 to 20,000 years ago).<ref>{{cite journal
 | last=Maslin | first=Mark
 | coauthors=Malhi, Yadvinder; Phillips, Oliver; Cowling, Sharon
 | title=New views on an old forest: assessing the longevity, resilience and future of the Amazon rainforest
 | journal=Transactions of the Institute of British Geographers
 | year=2005 | volume=30 | issue=4 | pages=477–499
 | url=http://earth.leeds.ac.uk/ebi/publications/Maslin_2005.pdf
 |format=PDF| accessdate=September 25, 2008
 | doi=10.1111/j.1475-5661.2005.00181.x | archiveurl= http://web.archive.org/web/20081001191320/http://earth.leeds.ac.uk/ebi/publications/Maslin_2005.pdf| archivedate= October 01 2008 <!--DASHBot-->| deadurl= no}}</ref> However, the rainforest still managed to thrive during these glacial periods, allowing for the survival and evolution of a broad diversity of species.<ref name=yadvinder>{{cite book
 | first=Yadvinder | last=Malhi
 | coauthors=Phillips, Oliver | year=2005
 | title=Tropical forests & global atmospheric change
 | publisher=Oxford University Press
 | isbn=0-19-856706-5 }}</ref>

== References ==
{{Reflist}}



[[Category:FRainforests]]