Editing Poaceae (section)

== Ecology ==
[[File:Grasses in the Valles Caldera 2014-06-26.JPG|thumb|upright=1.15|Wind-blown grass in the [[Valles Caldera]] in New Mexico, United States]]
Grasses are the [[Dominance (ecology)|dominant]] vegetation in many habitats, including [[grassland]], [[salt-marsh]], [[reedswamp]] and [[steppes]]. They also occur as a smaller part of the vegetation in almost every other terrestrial habitat.{{citation needed|date=March 2016}}
Grass-dominated [[biome]]s are called grasslands. If only large, contiguous areas of grasslands are counted, these biomes cover 31% of the planet's land.<ref name="TimeLifeBooks-1985-2" /> Grasslands include [[pampas]], [[steppe]]s, and [[prairie]]s.<ref>{{Cite book|url=https://books.google.com/books?id=uY_Y233ROE0C&q=Grasslands+include+pampas%2C+steppes%2C+and+prairies.&pg=PA108|title=The Field Guide to Geology|last=Lambert|first=David|date=2006|publisher=Infobase Publishing|isbn=9781438130057|language=en|url-status=live|archive-url=https://web.archive.org/web/20180110150237/https://books.google.com/books?id=uY_Y233ROE0C&pg=PA108&dq=Grasslands+include+pampas,+steppes,+and+prairies.&hl=en&sa=X&ved=0ahUKEwjbhqj0163VAhUoqVQKHXQBCrMQ6AEINDAF#v=onepage&q=Grasslands%20include%20pampas,%20steppes,%20and%20prairies.&f=false|archive-date=2018-01-10}}</ref>
Grasses provide food to many [[Grazing (behaviour)|grazing]] mammals,<ref>{{Cite book|last=Cheplick|first=G. P.|url=https://books.google.com/books?id=ID9o08AvrIQC&pg=PA1|title=Population Biology of Grasses|date=1998-03-28|publisher=Cambridge University Press|isbn=978-0-521-57205-7|language=en}}</ref> as well as to many species of [[Butterfly|butterflies]] and [[moth]]s.<ref>{{Cite book|last=Common|first=I. F. B.|url=https://books.google.com/books?id=magzbmvdRvQC&pg=PA65|title=Moths of Australia|date=1990|publisher=BRILL|isbn=978-90-04-09227-3|language=en}}</ref><ref>{{Cite book|last=DK|url=https://books.google.com/books?id=hZR8dn7bYIYC&pg=PA28|title=DK Eyewitness Books: Butterfly and Moth: Discover the Enchanting and Secret Life of Butterflies and Moths in Vivid Detail|date=2000-05-31|publisher=Penguin|isbn=978-0-7566-6908-9|language=en}}</ref>
Many types of animals eat grass as their main source of food, and are called ''[[graminivore]]s'' – these include [[cattle]], [[sheep]], [[horse]]s, [[rabbit]]s and many [[invertebrate]]s, such as [[grasshopper]]s and the caterpillars of many [[Satyridae|brown butterflies]]. Grasses are also eaten by [[Omnivore|omnivorous]] or even occasionally by primarily [[Carnivore|carnivorous]] animals.

[[File:Kangur.rudy.drs.jpg|thumb|right|A [[kangaroo]] eating grass]]
Grasses dominate certain [[biome]]s, especially [[Temperate grasslands, savannas, and shrublands|temperate grasslands]], because many species are adapted to grazing and fire.<ref>{{Cite book|last1=Orians|first1=Gordon H.|url=https://books.google.com/books?id=Ve6sKijB5tEC&pg=PA326|title=Life Study Guide: The Science of Biology|last2=Sadava|first2=David E.|last3=Heller|first3=Craig|last4=Purves|first4=William K.|date=2006-12-22|publisher=Macmillan|isbn=978-0-7167-7893-6|language=en}}</ref>

Grasses are unusual in that the [[meristem]] is near the bottom of the plant; hence, grasses can quickly recover from cropping at the top.<ref>{{cite web |url=http://www.farmwest.com/book/export/html/828 |title=Chapter 1: How grasses grow |publisher=Farmwest.com |access-date=2013-08-26 |url-status=live |archive-url=https://web.archive.org/web/20130910022122/http://www.farmwest.com/book/export/html/828 |archive-date=2013-09-10 }}</ref>
The evolution of large grazing animals in the [[Cenozoic]] contributed to the spread of grasses. Without large grazers, fire-cleared areas are quickly colonized by grasses, and with enough rain, tree seedlings. Trees eventually outcompete most grasses. Trampling grazers kill seedling trees but not grasses.<ref name="Attenborough-1984"/>{{rp|137}}