Ecological Niches in the Everglades

The Everglades — a slow-moving "River of Grass" — supports a mosaic of niches defined by hydroperiod (flood duration), fire, and nutrient gradients.

Foundational Niches

• Producers: Periphyton (algal/bacterial mats) — base of food web; Sawgrass (Cladium) — peat builder; Slough vegetation (Nymphaea, Nymphoides).
• Primary Consumers: Apple snails (Pomacea) — kite food; Grass shrimp, crayfish; Herbivorous fish (flagfish, mosquitofish).
• Secondary Consumers: Wading birds (wood stork, ibis, herons); Snail kite (specialist on apple snails); Gar, bowfin, bass.
• Apex Predators: American alligator — engineer (gator holes = dry-season refugia); Florida panther (upland); American crocodile (coastal).
• Decomposers: Bacteria, fungi — anaerobic peat decomposition; nutrient recycling.

Specialist Niches

• Bromeliads (epiphytes): Tank habitats for frogs, insects, ostracods — "aerial aquaria."
• Tree islands (hammocks): Nutrient-rich refugia; hardwoods, wildlife corridors.
• Marl prairies: Calcareous periphyton mats; short hydroperiod; Cape Sable seaside sparrow habitat.
• Mangrove ecotone: Salinity gradient; nursery for snook, tarpon, pink shrimp.

Interdependence

Alligators dig holes → retain water → fish survive dry down → birds feed → nutrients recycled → periphyton grows → snails graze → kites eat snails. Fire resets succession, releases nutrients. Hydrology is the master variable.

Threats

• Altered hydrology (C&SF Project) — compartmentalization, reduced flow.
• Nutrient pollution (phosphorus) — cattail invasion, periphyton loss.
• Invasives (Burmese python, melaleuca, Brazilian pepper).
• Climate change — sea-level rise, salinity intrusion.

Restoration (CERP) aims to restore the "ridge-slough-tree island" mosaic and its niche architecture.