词条 | Everglades |
释义 | Everglades region, Florida, United States Introduction ![]() Natural environment ![]() The organic soils, formed from the decay of lush vegetation, range from discontinuous shallow patches to accumulations of peat and muck 8 to 10 feet (2.4 to 3 metres) thick near Lake Okeechobee (Okeechobee, Lake). The best soils are deep mucks found in a narrow zone along the lakeshore, where a dense tangle of custard apple, or pond apple, once grew. The climate of the Everglades is tropical to subtropical and is influenced strongly by the southeast trade winds. Monthly mean temperatures range from 63 °F (17 °C) to 82 °F (28 °C), though winter frosts occur on rare occasions. Rainfall averages 40 to 65 inches (1,000 to 1,650 mm) annually, with most coming between May and October. During that period the land is nearly covered with a sheet of water. In the dry season (December–April), however, water levels drop and leave it dotted with small pools. The marsh provides habitat for more than 350 bird species. There are wading birds such as egrets, herons, roseate spoonbills, and ibis; shore and water birds such as terns, plovers, rails, and sandpipers; birds of prey including owls, hawks, and osprey; and a wide variety of songbirds. Several game fish species make their homes there. The Everglades is known for its population of alligators; bobcats, white-tailed deer, river otters, gray foxes, and many types of snakes, lizards, and turtles also live there. The area provides habitat for endangered species such as the manatee, Florida panther, wood stork, American crocodile, and several species of sea turtle. The population of wading birds in the Everglades has fallen drastically since the mid-20th century. Early inhabitants To the Native Americans of the region, the Everglades was known as Pa-Hay-Okee (“Grassy Water”). Its vast areas of open saw grass were used as passage for dugout canoes and as hunting and fishing territory. Although there was little settlement within the Everglades, mounds remain to indicate occupancy. The nearby coastal regions were inhabited by Calusa and Tequesta Indians when European explorers first arrived in the 16th century. Contact with Europeans was marked by warfare, disease, and other depredations, and both these groups were largely gone from the region by the late 1700s. Creek peoples then began to move into the area and became known as Seminoles (Seminole). The Seminoles found sanctuary in the swamps and marshes because the white settlers did not covet the glades at the time. They developed the “chickee,” a dwelling without walls, made of a log framework with a thatched roof over a raised platform, that assured maximum ventilation. They planted corn (maize), beans, melons, and squash on patches of higher ground and gathered nuts, roots, and palmetto berries. The bulbous roots of the coontie plant were the source of a starchy flour, and hunting and fishing provided much of their sustenance. Most were forced out during the Second Seminole War (1835–42). The Miccosukee tribe (formerly part of the Seminole tribe) continued to make their home in the Everglades into the 21st century. Development of the Everglades After the Seminole Wars, which occurred sporadically from 1817 to 1858, interest in the Everglades centred on exploiting its wildlife, especially the heron and egret for their feathers and the alligator for its hide. Drastic reductions in wildlife numbers led to legislation in the early 20th century that protected “plume birds”; alligator hunting was similarly restricted in the 1960s, and the alligator spent several years on the endangered-species list as populations recovered. drainage remained the principal focus of engineering in the glades for many years. These projects have been at best a mixed blessing. The natural Everglades drainage system, supplied with fresh water solely by rainfall, once covered more than 11,000 square miles (28,500 square km) from the Kissimmee River basin to Lake Okeechobee and southward to the Gulf of Mexico, Florida Bay, and the Atlantic Ocean. Ranging in depth from 3 feet (0.9 metre) to 6 inches (15 cm), the water slowly flowed southward down the peninsula at a rate of about 100 feet (30 metres) a day. Efforts to drain the marsh began in the 1800s, canal construction in the 1880s, and dredging for agricultural purposes between 1905 and 1910. Laws passed in 1948 required that levees and canals be constructed to prevent flooding in the South Florida region and to provide water for human use. Rainwater was pumped out of the area and released into the ocean or diverted to farms and cities. Everglades water levels were artificially altered in an erratic manner, disturbing the quality, amount, distribution, and timing of the seasonal cycle. In addition, nearly 1,200 square miles (3,100 square km) of land immediately south of Lake Okeechobee was drained and converted to cropland for the production of sugarcane, vegetables, and beef cattle, cutting off the rest of the Everglades from the lake. These changes in the natural water flow as well as runoff from farmland brought about radical alterations in the natural habitat, producing toxic algae, killing sea-grass beds, creating high levels of organic mercury, and flooding seasonal wildlife feeding and nesting sites. Encroaching urban areas and the introduction of exotic species also contributed to ecological problems; roughly half of the original natural Everglades area has now been destroyed. Efforts to preserve the Everglades ecosystem date to the mid-20th century, notably in the work of conservationists Marjory Stoneman Douglas and Ernest F. Coe. Government discussions on how to reverse the region's ecological damage began in the early 1970s, initially at the state level but especially after 1990 through federal initiatives. A restoration plan, passed by the U.S. Congress in 2000, was expected to be implemented over several decades. It called for the removal of levees and for changes in water management to more closely mimic the natural process; water pumped out was to be stored in a reservoir system and redistributed onto the land. The plan was intended not only to restore the Everglades environment but to preserve the profitable tourism industry and ensure adequate freshwater supplies for agriculture and the burgeoning population of South Florida. ![]() Additional Reading Marjory Stoneman Douglas, The Everglades: River of Grass, rev. ed. (1988), is a well-written and well-documented volume. Alfred Jackson Hanna and Kathryn Abbey Hanna, Lake Okeechobee: Wellspring of the Everglades (1948, reprinted 1973), provides a regional history. David McCally, The Everglades: An Environmental History (1999), covers the area's development from its geologic origins to 20th-century agriculture. Glen Simmons and Laura Ogden, Gladesmen: Gator Hunters, Moonshiners, and Skiffers (1998), provides a portrait of life in the Everglades in the 1930s. |
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