Everglades National Park was founded in 1947 in southern Florida to protect the fauna and flora of a territory of 600,000 hectares (6,000 square km or 2,400 square mi) of an unique but fragile beauty, one of the ecologically most menaced American territories. 1.400 mi (2.200 km) of canals and 125 surveillance structures monitor the water in the park. The quantity, quality, moment and distribution method of the water are vital for the survival and regeneration of this subtropical paradise; the reproductive cycles of the birds, alligators and other wild species depend on the seasonal fluctuations of the water in the park. In 1976, Everglades was declared Reservation of the Biosphere.
The swampy ecosystem of Everglades starts 400 km (250 mi) far north, in Kissimmee Basin. The territory has an inclination of just 5 cm (2 in) at 1.5 km (0.9 mi). The slightest variation in the water level can get the birds starving or flood the alligator nests.
Everglades hosts over 350 bird species and over 1,000 plant species, including 120 tree species. The landscape varies from estuaries and sedge fields to mangrove islands and pine forests. 12 menaced species of plants and animals are found here. Tourists can fish, make boat rides or photo safaris. Canoe routes can be made in the sedge fields.
Unprovoked fires can occur in Everglades, due to lightnings, especially at the end of the spring and beginning of the summer. In the pine forests, the fire hampers the growth of the lower vegetation level (made of dwarf palms), so that the pines can regenerate. The fire also kills another tree species that would invade and suffocate the pine forests. Controlled fires are used for maintaining the biodiversity.
Everglades may be famous due to its alligator population, but this is also the only place in the world where you can find both alligators and crocodiles. This is also the only place in US where crocodiles (Crocodylus americanus) are found.
Shallow waters, of less then 1.8 m (6 ft) are invaded by mangrove trees. Their roots decrease the speed of the waves and retain the sediments, helping the formation of new land. A hectare of mangroves produces annually 7.5 tonnes of leaves, which depose at the bottom of the water, and represent the base of a food chain involving shrimps, fish, birds and humans.