Editing Everglades (section)

==Ecosystems==
{{Main|Geography and ecology of the Everglades}}

[[File:Historic Everglades Regions.jpg|thumb|Major landscape types in the Everglades before human action. Source: U.S. Geological Survey]]

===Sawgrass marshes and sloughs===

Several ecosystems are present in the Everglades, and boundaries between them are subtle or absent. The primary feature of the Everglades is the [[Cladium|sawgrass]] marsh. The iconic water and sawgrass combination in the shallow river {{convert|100|mi|km}} long and {{convert|60|mi|km}} wide that spans from Lake Okeechobee to Florida Bay is often referred to as the "true Everglades" or just "the Glades".<ref>George, p.&nbsp;13.</ref><ref>Douglas, p.&nbsp;11.</ref>  Prior to the first drainage attempts in 1905, the sheetflow occupied nearly a third of the lower Florida peninsula.<ref name="McCally9-10"/> Sawgrass thrives in the slowly moving water, but may die in unusually deep floods if oxygen is unable to reach its roots. It is particularly vulnerable immediately after a fire.<ref>Whitney, p.&nbsp;168.</ref> The hydroperiod for the marsh is at least nine months, and can last longer.<ref>Jewell, p.&nbsp;46.</ref> Where sawgrass grows densely, few animals or other plants live, although [[alligator]]s choose these locations for nesting. Where there is more room, [[periphyton]] grows.<ref>Whitney,&nbsp;p.168.</ref> Periphyton supports larval insects and amphibians, which in turn are consumed as food by birds, fish, and reptiles. It also absorbs [[calcium]] from water, which adds to the calcitic composition of the marl.<ref>George, p.&nbsp;42.</ref>

[[Sloughs]], or free-flowing channels of water, develop in between sawgrass prairies. Sloughs are about {{convert|3|ft|m}} deeper than sawgrass marshes, and may stay flooded for at least 11&nbsp;months out of the year and sometimes multiple years in a row.<ref>Lodge, p.&nbsp;31.</ref> Aquatic animals such as turtles, alligators, snakes, and fish thrive in sloughs; they usually feed on aquatic invertebrates.<ref>George, p.&nbsp;14.</ref> Submerged and floating plants grow here, such as bladderwort (''[[Utricularia]]''), waterlily (''[[Nymphaeaceae]]''), and spatterdock (''[[Nuphar lutea]]''). Major sloughs in the Everglades system include the [[Shark River Slough]] flowing out to Florida Bay, Lostmans River Slough bordering The Big Cypress, and [[Taylor Slough]] in the eastern Everglades.

Wet prairies are slightly elevated like sawgrass marshes, but with greater plant diversity. The surface is covered in water only three to seven months of the year, and the water is, on average, shallow at only {{convert|4|in|cm}} deep.<ref>Lodge, p.&nbsp;29.</ref> When flooded, the marl can support a variety of water plants.<ref>Whitney, p.&nbsp;164.</ref> [[sinkhole|Solution holes]], or deep pits where the limestone has worn away, may remain flooded even when the prairies are dry, and they support aquatic invertebrates such as [[crayfish]] and snails, and larval amphibians which feed young wading birds.<ref>Whitney, p.&nbsp;163.</ref> These regions tend to border between sloughs and sawgrass marshes.
[[File:Alligator in the Everglades.jpg|thumb|Alligator in the Everglades]]
Alligators have created a niche in wet prairies. With their claws and snouts they dig at low spots and create ponds free of vegetation that remain submerged throughout the dry season. Alligator holes are integral to the survival of aquatic invertebrates, turtles, fish, small mammals, and birds during extended drought periods. The alligators then feed upon some of the animals that come to the hole.<ref>George, pp.&nbsp;45–46.</ref><ref>Lodge, p.&nbsp;35.</ref>

===Tropical hardwood hammock===
[[File:Everglades Hammock Center.JPG|thumb|In a tropical hardwood hammock, trees are very dense and diverse.]]
{{Main|Tropical hardwood hammock}}

Small islands of trees growing on land raised between {{convert|1|and|3|ft|m}} above sloughs and prairies are called tropical hardwood [[hammock (ecology)|hammocks]].<ref>George, p.&nbsp;30.</ref> They may range from one (4,000&nbsp;m<sup>2</sup>) to ten acres (40,000&nbsp;m<sup>2</sup>) in area, and appear in freshwater sloughs, sawgrass prairies, or pineland. Hammocks are slightly elevated on limestone plateaus risen several inches above the surrounding peat, or they may grow on land that has been unharmed by deep peat fires. Hardwood hammocks exhibit a mixture of subtropical and hardwood trees, such as Southern live oak (''[[Quercus virginiana]]''), gumbo limbo (''[[Bursera simaruba]]''), royal palm (''[[Roystonea]]''), and bustic (''[[Dipholis salicifolia]]'') that grow in very dense clumps.<ref>Douglas, pp.&nbsp;48–49.</ref> Near the base, sharp saw palmettos (''[[Serenoa repens]]'') flourish, making the hammocks very difficult for people to penetrate, though small mammals, reptiles and amphibians find these islands an ideal habitat. Water in sloughs flows around the islands, creating [[moat]]s. Although some ecosystems are maintained and promoted by fire, hammocks may take decades or centuries to recover. The moats around the hammocks protect the trees.<ref>George, p.&nbsp;31.</ref> The trees are limited in height by weather factors such as frost, lightning, and wind; the majority of trees in hammocks grow no higher than {{convert|55|ft|m}}.

===Pineland===
Some of the driest land in the Everglades is pineland (also called pine rockland) ecosystem, located in the highest part of the Everglades with little to no hydroperiod. Some floors, however, may have flooded solution holes or puddles for a few months at a time. The most significant feature of the pineland is the single species of South Florida slash pine (''[[Pinus elliottii]]''). Pineland communities require fire to maintain them, and the trees have several adaptations that simultaneously promote and resist fire.<ref name="fwspine">U.S. Fish & Wildlife Service. "[http://www.fws.gov/southeast/vbpdfs/commun/pr.pdf South Florida Multi-Species Recovery Plan: Pine rockland] {{Webarchive|url=https://web.archive.org/web/20121111003517/http://www.fws.gov/southeast/vbpdfs/commun/pr.pdf |date=2012-11-11 }}", Retrieved May 3, 2008.</ref> The sandy floor of the pine forest is covered with dry pine needles that are highly flammable. South Florida slash pines are insulated by their bark to protect them from heat. Fire eliminates competing vegetation on the [[forest floor]], and opens pine cones to germinate seeds.<ref>George, pp.&nbsp;7–8.</ref> A period without significant fire can turn pineland into a hardwood hammock as larger trees overtake the slash pines.<ref name="usgsfire">{{cite web| title = Land and Resource Management Projects| work = DOI science plan in support of ecosystem restoration, preservation, and protection in South Florida| publisher = U.S. Geological Survey| date = April 26, 2007| url = http://sofia.usgs.gov/publications/reports/doi-science-plan/managefire.html| access-date = 2008-05-02| archive-date = May 12, 2009| archive-url = https://web.archive.org/web/20090512061559/http://sofia.usgs.gov/publications/reports/doi-science-plan/managefire.html| url-status = dead}}</ref> The [[understory]] shrubs in pine rocklands are the fire-resistant saw palmetto (''[[Serenoa repens]]''), cabbage palm (''[[Sabal palmetto]]''), and West Indian lilac (''[[Tetrazygia bicolor]]''). The most diverse group of plants in the pine community are the herbs, of which there are two dozen species. These plants contain [[tuber]]s and other mechanisms that allow them to sprout quickly after being charred.<ref>Lodge, p.&nbsp;66.</ref>

Prior to urban development of the South Florida region, pine rocklands covered approximately {{convert|161660|acre|km2}} in [[Miami-Dade County, Florida|Miami-Dade County]]. Within Everglades National Park, {{convert|19840|acre|km2}} of pine forests are protected, but outside the park, {{convert|1780|acre|km2}} of pine communities remained as of 1990, averaging {{convert|12.1|acre|m2}} in area.<ref name="fwspine"/> The misunderstanding of the role of fire also played a part in the disappearance of pine forests in the area, as natural fires were put out and pine rocklands transitioned into hardwood hammocks. [[Prescribed fire]]s occur in Everglades National Park in pine rocklands every three to seven years.<ref>Lodge, p.&nbsp;63.</ref>

<!-- distance check is complete -->{{wide image|Everglades vegetation cross section.gif|600px|A cross section of fresh water ecosystems in the Everglades, with relative average water depths}}

===Cypress===
[[File:Big cypress.jpg|thumb|A pond in The Big Cypress]]

Cypress swamps can be found throughout the Everglades, but the largest covers most of [[Collier County, Florida|Collier County]]. The Big Cypress Swamp is located to the west of the sawgrass prairies and sloughs, and it is commonly called "The Big Cypress".<ref name="George, p. 26">George, p.&nbsp;26.</ref> The name refers to its area rather than the height or diameter of the trees; at its most conservative estimate, the swamp measures {{convert|1200|sqmi|km2}}, but the [[Hydrography|hydrologic boundary]] of The Big Cypress can be calculated at over {{convert|2400|sqmi|km2}}.<ref>Lodge, p.&nbsp;67.</ref> Most of The Big Cypress sits atop a bedrock covered by a thinner layer of limestone. The limestone underneath the Big Cypress contains [[quartz]], which creates sandy soil that hosts a variety of vegetation different from what is found in other areas of the Everglades.<ref name="George, p. 26"/> The basin for The Big Cypress receives on average {{convert|55|in|cm}} of water in the wet season.<ref>Ripple, p.&nbsp;16.</ref>

Although The Big Cypress is the largest growth of cypress swamps in South Florida, cypress swamps can be found near the Atlantic Coastal Ridge and between Lake Okeechobee and the Eastern flatwoods, as well as in sawgrass marshes. Cypresses are deciduous [[conifer]]s that are uniquely adapted to thrive in flooded conditions, with buttressed trunks and root projections that protrude out of the water, called "knees".<ref>Jewell, p.&nbsp;43.</ref> [[Taxodium distichum|Bald cypress]] trees grow in formations with the tallest and thickest trunks in the center, rooted in the deepest peat. As the peat thins out, cypresses grow smaller and thinner, giving the small forest the appearance of a dome from the outside.<ref>Ripple, p.&nbsp;26.</ref> They also grow in strands, slightly elevated on a ridge of limestone bordered on either side by sloughs.<ref>Ripple, pp.&nbsp;31–32.</ref> Other hardwood trees can be found in cypress domes, such as [[red maple]], [[swamp bay]], and [[pop ash]]. If cypresses are removed, the hardwoods take over, and the ecosystem is recategorized as a mixed swamp forest.

===Mangrove and Coastal prairie===
[[File:Mangrove trees in Everglades.JPG|thumb|Red [[mangrove]] trees bordering a tidal [[estuary]] in the Everglades]]

Eventually the water from Lake Okeechobee and The Big Cypress makes its way to the ocean. Mangrove trees are well adapted to the transitional zone of [[brackish]] water where fresh and salt water meet.<ref>Katherisen, K. (2001). "Biology of Mangroves and Mangrove Ecosystems", ''Advances in Marine Biology'', Alan J. Southward (ed.) '''40''', pp.&nbsp;18–251. {{ISBN|978-0-12-026140-6}}.</ref> The estuarine ecosystem of the [[Ten Thousand Islands]], which is comprised almost completely of mangrove forests, covers almost {{convert|200000|acre|km2}}.<ref name="Ripple"/>  In the wet season fresh water pours out into Florida Bay, and sawgrass begins to grow closer to the coastline. In the dry season, and particularly in extended periods of drought, the salt water creeps inland into the coastal prairie, an ecosystem that buffers the freshwater marshes by absorbing sea water. Mangrove trees begin to grow in fresh water ecosystems when the salt water goes far enough inland.<ref>George, p.&nbsp;19.</ref>

There are three species of trees that are considered mangroves: red (''[[Rhizophora mangle]]''), black (''[[Avicennia germinans]]''), and white (''[[Laguncularia racemosa]]''), although all are from different families.<ref>Jewell, p.&nbsp;41.</ref> All grow in oxygen-poor soil, can survive drastic water level changes, and are tolerant of salt, brackish, and fresh water.<ref>Whitney, p.&nbsp;286.</ref> All three mangrove species are integral to coastline protection during severe storms. Red mangroves have the farthest-reaching roots, trapping sediments that help build coastlines after and between storms. All three types of trees absorb the energy of waves and [[storm surge]]s. Everglades mangroves also serve as nurseries for [[crustaceans]] and fish, and rookeries for birds. The region supports Tortugas pink shrimp (''[[Farfantepenaeus duorarum]]'') and stone crab (''[[Menippe mercenaria]]'') industries;<ref>{{cite web| title= About Florida Bay| publisher= Sea Grant Florida| date = July 16, 2001| url=http://www.floridabay.org/intro.shtml| access-date=2008-06-08}}</ref> between 80 and 90 percent of commercially harvested crustacean species in Florida's salt waters are born or spend time near the Everglades.<ref name="Ripple">Ripple, p.&nbsp;80.</ref><ref>{{cite web|last = Humphreys|first = Jay|author2 = Franz, Shelley|author3 = Seaman, Bill|title = Florida's Estuaries: A Citizen's Guide to Coastal Living and Conservation|publisher = National Atmosphere and Oceanic Administration and the Florida Department of Community Affairs|date = March 1993|url = http://nsgl.gso.uri.edu/flsgp/flsgph93001.pdf|access-date = 2008-06-08|archive-url = https://web.archive.org/web/20160303231821/http://nsgl.gso.uri.edu/flsgp/flsgph93001.pdf|archive-date = 2016-03-03|url-status = dead
}}</ref>

===Florida Bay===
{{Main|Florida Bay}}
[[File:Florida Bay at Flamingo.JPG|thumb|A clump of mangroves in the distance, [[Florida Bay]] at [[Flamingo, Florida|Flamingo]]]]

Much of the coast and the inner estuaries are built of mangroves; there is no border between the coastal marshes and the bay. Thus the marine ecosystems in [[Florida Bay]] are considered to be a part of the Everglades watershed and one of the ecosystems connected to and affected by the Everglades as a whole. More than {{convert|800|sqmi|km2}} of Florida Bay is protected by [[Everglades National Park]], representing the largest body of water in the park boundaries.<ref>{{cite web| title = Ecosystems: Marine & Estuarine| publisher= National Park Service| date= July 30, 2007| url= http://www.nps.gov/ever/naturescience/marineestuarine.htm| access-date = 2008-05-04}}</ref> There are approximately 100 [[cay|keys]] in Florida Bay, many of which are mangrove forests.<ref>George, p.&nbsp;21.</ref> The fresh water coming into Florida Bay from the Everglades creates perfect conditions for vast beds of [[seagrass|turtle grass]] and algae formations that are the foundation for animal life in the bay. [[Sea turtle]]s and [[manatee]]s eat the grass, while invertebrate animals, such as worms, clams and other mollusks eat the algae formations and microscopic plankton.<ref>Whitney, pp.&nbsp;313–316.</ref> Female sea turtles return annually to nest on the shore, and manatees spend the winter months in the warmer water of the bay. Sea grasses also serve to stabilize the sea beds and protect shorelines from erosion by absorbing energy from waves.