Editing Yellowstone National Park (section)

=== Flora ===
Over 69,000 [[species]] of trees and other [[vascular plant]]s are native to the park. Another 170 species are considered to be [[exotic species]] and are non-native. Of the eight [[conifer]] tree species documented, [[lodgepole pine]] forests cover 80% of the total forested areas.<ref name="facts"/> Other conifers, such as [[subalpine fir]], [[Engelmann spruce]], [[Rocky Mountain Douglas-fir]] and [[whitebark pine]], are found in scattered groves throughout the park. As of 2007,{{update after|2021|3|4}} the whitebark pine is threatened by a fungus known as [[Cronartium ribicola|white pine blister rust]]; however, this is mostly confined to forests well to the north and west. In Yellowstone, about seven percent of the whitebark pine species have been impacted with the fungus, compared to nearly complete infestations in northwestern Montana.<ref name="whitebark">{{cite web |last=Kendall |first=Katherine |url=http://biology.usgs.gov/s+t/SNT/noframe/wm147.htm |title=Whitebark Pine |website=Our Living Resources |publisher=U.S. Geological Survey |access-date=March 13, 2007 |archive-url=https://web.archive.org/web/20060927145101/http://biology.usgs.gov/s%2Bt/SNT/noframe/wm147.htm |archive-date=September 27, 2006 |url-status=dead }}</ref> [[Quaking Aspen]] and [[willow]]s are the most common species of [[deciduous]] trees. The aspen forests have declined significantly since the early 20th century, but scientists at Oregon State University attribute the recent recovery of the aspen to the [[History of wolves in Yellowstone|reintroduction of wolves]] which has changed the grazing habits of local elk.<ref name="aspen">{{cite web |title=Presence Of Wolves Allows Aspen Recovery in Yellowstone |url=https://www.sciencedaily.com/releases/2007/07/070726150904.htm |access-date=August 1, 2007 |url-status=live |archive-url=https://web.archive.org/web/20071001001225/https://www.sciencedaily.com/releases/2007/07/070726150904.htm |archive-date=October 1, 2007 }}</ref>
[[File:Abronia ammophila.jpg|thumb|[[Abronia ammophila|Yellowstone sand verbena]] is endemic to Yellowstone's lakeshores]]

There are dozens of species of flowering plants that have been identified, most of which bloom between May and September.<ref name="flowers">{{cite web |url=http://www.nps.gov/yell/naturescience/upload/286wildflowers.pdf |title=Where Are the Bloomin' Wildflowers? |publisher=National Park Service |date=February 2004 |access-date=March 13, 2007 |url-status=live |archive-url=https://web.archive.org/web/20070616094322/http://www.nps.gov/yell/naturescience/upload/286wildflowers.pdf |archive-date=June 16, 2007 }}</ref> The [[Abronia ammophila|Yellowstone sand verbena]] is a rare flowering plant found only in Yellowstone. It is closely related to species usually found in much warmer climates, making the sand verbena an enigma. The estimated 8,000 examples of this rare flowering plant all make their home in the sandy soils on the shores of Yellowstone Lake, well above the waterline.<ref name="verbena">{{cite web |url=http://www.nps.gov/yell/naturescience/verbena.htm |title=Yellowstone Sand Verbena |website=Nature and Science |publisher=National Park Service |date=July 20, 2006 |access-date=March 13, 2007 |url-status=live |archive-url=https://web.archive.org/web/20070607165823/http://www.nps.gov/yell/naturescience/verbena.htm |archive-date=June 7, 2007 }}</ref>
[[File:Microbes, Yellowstone National Park.jpg|thumb|Microbial mat in cooled geyser water, Upper Geyser Basin]]
In Yellowstone's hot waters, bacteria form mats of bizarre shapes consisting of trillions of organisms. These bacteria are some of the most primitive life forms on earth. Flies and other [[arthropod]]s live on the mats, even in the middle of the bitterly cold winters. Initially, scientists thought that microbes there gained sustenance only from [[sulfur]]. In 2005 researchers from the [[University of Colorado at Boulder]] discovered that the sustenance for at least some of the diverse [[Hyperthermophile|hyperthermophilic]] species is [[hydrogen|molecular hydrogen]].<ref name="bacteria">{{cite web |url=http://www.colorado.edu/news/releases/2005/30.html |title=Microbes in Colorful Yellowstone Hot Springs Fueled By Hydrogen, CU-Boulder Researchers Say |publisher=University of Colorado at Boulder |date=January 24, 2005 |access-date=March 13, 2007 |url-status=dead |archive-url=https://web.archive.org/web/20130426150324/http://www.colorado.edu/news/releases/2005/30.html |archive-date=April 26, 2013 }}</ref>

''[[Thermus aquaticus]]'' is a [[Bacteria|bacterium]] found in the Yellowstone hot springs that produces an important enzyme (Taq polymerase) that is easily replicated in the lab and is useful in replicating [[DNA]] as part of the [[polymerase chain reaction]] (PCR) process. The retrieval of these bacteria can be achieved with no impact on the ecosystem. Other bacteria in the Yellowstone hot springs may also prove useful to scientists who are searching for cures for various diseases.<ref>{{cite web |title=The Yellowstone Thermophiles Conservation Project |publisher=World Foundation for Environment and Development |url=http://www.wfed.org/projects/yellowstone/project.htm |date=April 27, 2004 |access-date=March 15, 2007 |url-status=usurped |archive-url=https://web.archive.org/web/20070320104815/http://www.wfed.org/projects/yellowstone/project.htm |archive-date=March 20, 2007 }}</ref> In 2016, researchers from Uppsala University reported the discovery of a class of thermophiles, [[Hadesarchaea]], in Yellowstone's Culex Basin. These organisms are capable of converting carbon monoxide and water to carbon dioxide and hydrogen.<ref name=Baker>{{cite journal |last1=Baker |first1=Brett J. |last2=Saw |first2=Jimmy H. |last3=Lind |first3=Anders E. |last4=Lazar |first4=Cassandra Sara |last5=Hinrichs |first5=Kai-Uwe |last6=Teske |first6=Andreas P. |last7=Ettema |first7=Thijs J.G. |title=Genomic inference of the metabolism of cosmopolitan subsurface Archaea, Hadesarchaea |journal=Nature Microbiology |volume=1 |issue=3 |pages=16002 |date=February 16, 2016 |language=en |doi=10.1038/nmicrobiol.2016.2 |pmid=27572167 |doi-access=free }}</ref><ref name=IBTimes>{{cite web |last=Atherton |first=Matt |url=http://www.ibtimes.co.uk/god-underworld-microbes-hadesarchaea-discovered-living-toxic-gas-deep-below-yellowstone-hot-1543919 |title=God of the underworld microbes Hadesarchaea discovered living on toxic gas deep below Yellowstone hot springs |website=IB Times |date=February 15, 2016 |access-date=February 25, 2016 |url-status=live |archive-url=https://web.archive.org/web/20160229090040/http://www.ibtimes.co.uk/god-underworld-microbes-hadesarchaea-discovered-living-toxic-gas-deep-below-yellowstone-hot-1543919 |archive-date=February 29, 2016 }}</ref>

Non-native plants sometimes threaten native species by occupying nutrient resources. Though exotic species are most commonly found in areas with the greatest human visitation, such as near roads and at major tourist areas, they have also spread into the backcountry. Generally, most exotic species are controlled by pulling the plants out of the soil or by spraying, both of which are time-consuming and expensive.<ref name="exotic">{{cite web |url=http://www.nps.gov/yell/naturescience/upload/ExoticVeg_2_1_06.pdf |title=Exotic Vegetation Management in Yellowstone National Park |website=Nature and Science |publisher=National Park Service |date=February 1, 2006 |access-date=March 13, 2007 |url-status=live |archive-url=https://web.archive.org/web/20070612125909/http://www.nps.gov/yell/naturescience/upload/ExoticVeg_2_1_06.pdf |archive-date=June 12, 2007 }}</ref>