Periphyton occurs as either as an algal mat or as a submerged algal growth.
This algae provides an excellent food source for both fish and snails within the
Everglades. There are two types of periphyton one which grows over peat soils and the other
which grow over soils that contain abundant calcium. The periphyton which grows
over calcitic soils contains a higher content of blue-green algae and usually occurs
as submerged growth.
The algal mat type of periphyton (seen in the aerial photograph) grows on the water surface and contains a greater amount of green algae. These mats occur in areas with a longer hydroperiod and form an impenetrable layer of organic material when dried. This impenetrable mat only allows Sawgrass (Cladium jamaicense) and spike rush (Eleocharis cellulosa) to penetrate it. Other species aren't able to get through this layer of organic material.
The type of periphyton that is able to exist within in an area is directly related to hydroperiod and thus hydroperiod can indirectly influence the vegetation within a prairie via periphyton. Overall, the growth of periphyton mats can have a considerable affect on species composition within the prairies of the Everglades.