SUBSTRATE:  Often sandy, but sometimes exposed limestone, silt, or clay.

TOPOGRAPHY/HYDROLOGY: Most rivers and streams slow flowing; some panhandle rivers originate at higher elevations and are faster flowing; most springs are artesian. Of 24 major rivers, 21 flow south or west to the Gulf, 2 flow north and east to the Atlantic, and one flows south to Lake Okeechobee.

VEGETATION/ALGAE: At least 130 species of aquatic plants in rivers, streams, and adjacent marshes; numerous planktonic algal species in larger, slow-flowing rivers and various kinds of springs.

FAUNA: Immature stages of many insects and extensive snail and mollusc fauna in rivers; crayfish common in clear, spring-fed rivers; at least 126 native fish species, with greatest number in west; Okaloosa darter, shortnose sturgeon, and West Indian manatee considered endangered.

PROCESSES/DYNAMICS/ABIOTIC FACTORS: Sand-bottom streams are slightly acidic and moderately colored; swamp-and-bog streams are very acidic and darkly colored; calcareous streams are cool, clear, and alkaline; large rivers carry considerable silt and clay and are always muddy.

HUMAN IMPACTS: Channelization, dredging, diversion, and dam construction; introduction of exotic plant and fish species; removal of groundwater, followed by saltwater intrusion; industrial pollution.

ANIMALS AND PLANTS NATIVE TO ECOSYSTEM: List of selectable animals and plants native to the Rivers and Springs ecosystem, with detailed descriptions and pictures on each.