South Florida Everglades

• Historically: Free-flowing ‘river of grass’ extending from the Kissimmee chain of lakes to Florida Bay.

• Since late 1800s: Construction of 3,000 km of canals and levees inter-rupting the Everglades' natural sheetflow, eliminating more than 50% of the wetlands and deterioration of water quality.SeaWiFS: April 1999

Upper chain of lakes Kissimmee River

Lake Okeechobee Water Conservation Areas

Mangrove island, Florida Bay

Tree islands

Coral reef, Florida Keys

Tall-grass wet prairies

Cypress swamps

Alligator holes

Florida Bay Mangroves

Annual precipitation (smoothing average), horizontal line = historic average.Richardson 2010

• Plant communities highly influenced by rainfall patterns combined with impact of drainage, dikes, and an occasional hurricane.

• Timing, frequency and amplitude of low and high water events.

• Shifts in rainfall also control nutrient loadings.

Historic map of the plant communities in the Everglades based on the map of J.H. Davis (1943). The map has been redrawn and simplified from the original map, and the boundaries of the current water conservation areas (WCA-1,WCA-2, WCA-3), the Everglades National Park (ENP), and the Everglades Agricultural Areas have been added (form Richardson 2010)

Shallow elevation gradient and overlying peat storage of water during wet periods and slow release during dry season.

Richardson 2010

Everglades Restoration

Plan• Restoration of natural

hydrological conditions• Restoration of wetland habitat

and biological populations• Improved water quality• Enhanced water supply for

agriculture and urban use• Continued flood protection• Cost: $7.8 billion (now $11

billion)• Duration: 30 years

Richardson 2010

Population-level considerationsMangroveManatee

Limpkin Alligator

Ecosystem-level considerationsLittoral zones of lakes

Cypress swamps

Sloughs

Tree islands

Kissimmee River Restoration

Vegetable farming Miami

Naturally-occurring brush fires Port St. Lucie

Succession patterns related to fire and hydroperiod in the Everglades. Modified from Richardson 2000

The current Everglades ecosystem is not simply rainfall driven.It depends on the restoration of peatland hydrology and nutrient

conditions.

It takes little ecological knowledge to preserve or totally restore natural conditions, ………..

but it takes enormous ecological knowledge to actively manage an area in order to restore or preserve some natural values while manipulating the ecosystem for other desirable ends