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Dami ng Post : 78 Puntos : 5396 Salamat : 0 Lokasyon : australia Nagpatala : 2010-08-14
| Subject: Freshwater marl March 3rd 2011, 6:25 pm | |
| Freshwater sloughs are perhaps the most common ecosystem associated with Everglades National Park. These drainage channels are characterized by low-lying areas covered in fresh water, flowing at an almost imperceptible 100 feet (30 m) per day.[19] Shark River Slough and Taylor Slough are significant features of the park. Sawgrass growing to a length of 6 feet (1.8 m) or more, and broad-leafed marsh plants, are so prominent in this region that they gave the Everglades its nickname "River of Grass". Excellent feeding locations for birds, sloughs in the Everglades attract a great variety of waders such as herons, egrets, roseate spoonbills (Platalea ajaja), ibises and brown pelicans (Pelecanus occidentalis), as well as limpkins (Aramus guarauna) and snail kites that eat apple snails, which in turn feed on the sawgrass. The sloughs' availability of fish, amphibians, and young birds attract a variety of freshwater turtles, alligators (Alligator mississippiensis), water moccasins (Agkistrodon piscivorus conanti), and eastern diamondback rattlesnakes (Crotalus adamanteus). A Great Blue Heron at Anhinga Trail Freshwater marl prairies are similar to sloughs, but lack the slow movement of water; instead, water seeps through a calcitic mud called marl. Algae and other microscopic organisms form periphyton, which attaches to limestone. When it dries it turns into a gray mud.[20] Sawgrass and other water plants grow shorter in freshwater marl than they do in peat, the other type of soil in the Everglades which is found where water remains present longer throughout the year. Marl prairies are usually under water from three to seven months of the year, whereas sloughs may remain submerged for longer than nine months and sometimes remain under water from one year to the next. Sawgrass may dominate sloughs, creating a monoculture. Other grasses, such as muhly grass (Muhlenbergia filipes) and broad-leafed water plants can be found in marl prairies.[21] Animals living in the freshwater sloughs also inhabit in marl prairies. Marl prairies may go dry in some parts of the year; alligators play a vital role in maintaining life in remote parts of the Everglades by burrowing in the mud during the dry season, and creating pools of water where fish and amphibians survive from one year to the next. Alligator holes also attract other animals who congregate to feed on smaller prey. When the region floods again during the wet season, the fish and amphibians who were sustained in the alligator holes then repopulate freshwater marl prairies.[22] leather vestexercise dvds | |
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