Clastic Upland Lake

Clastic Upland Lake - (synonyms: clay-bottomed lake, silt-bottomed lake, fluctuating or
disappearing lake, deep water lake, limesink).

Clastic Upland Lakes are generally characterized as shallow to relatively deep, irregular- shaped depressions or basins occurring in uplands on clay substrates. They are lentic water bodies with surface inflows but often without significant outflows. Water is generally dissipated through evaporation and transpiration, but it may also disappear, especially during prolonged droughts, through sinks that connect with the aquifer.

Vegetation varies substantially in Clastic Upland Lakes. Some portions of the water's edge may be dominated by hydrophytic shrubs, such as buttonbush, Virginia willow, wax myrtle, St. John's wort, primrose willow, elderberry, white alder, black titi, swamp privet, Carolina ash, witchhazel, large gallberry, hurrah-bush, and possumhaw. Other shorelines may be vegetated with sedges, grasses, and rushes; or they may be dominated by hydrophytic trees, such as bald cypress, water hickory, water oak, laurel oak, water elm, sweetbay magnolia, redbay, sweetgum, waterlocust, red maple, loblolly bay, and black gum. Shallow water zones of Clastic Upland Lakes are generally densely vegetated by concentric bands of emergents, floating, and submersed aquatics, including pickerelweed, arrowhead, banana-lily, American lotus, spatterdock, fragrant water lily, coontail, watermilfoil, bladderwort, fanwort, and pondweed.

Typical animals include Florida gar, bowfin, threadfin shad, chain pickerel, golden shiner, ironcolor shiner, redeye club, yellow bullhead, brown bullhead, pirate perch, golden topminnow, lined topminnow, pygmy killifish, mosquitofish, least killifish, brook silverside, flier, Okefenokee pygmy sunfish, bluespotted sunfish, warmouth, bluegill, redear sunfish, largemouth bass, black crappie, swamp darter, two-toed amphiuma, newts, sirens, cricket frog, bullfrog, pig frog, leopard frog, alligator, snapping turtle, Florida cooter, yellow-belly turtle, mud turtle, stinkpot, Florida softshell turtle, mud snake, green water snake, banded water snake, eastern garter snake, cottonmouth, great blue heron, great egret, snowy egret, little blue heron, green-backed heron, white ibis, wood stork, kingfisher, beaver, and river otter.

Clastic Upland Lakes generally have clay and organic substrates. Their water is characteristically clear to colored, circumneutral to slightly acidic, and soft with a low mineral content (particularly sodium, chloride, and sulfate). Clastic Upland lakes may be oligomesotrophic, with relatively low nutrient levels, to eutrophic, with very high nutrient levels, depending upon their geologic age and nutrient supplements from the surrounding uplands.

Clastic Upland Lakes are important breeding areas for many terrestrial and semi-aquatic amphibians. They are frequently very important feeding and nesting areas for many wading birds, ducks, reptiles, and fish. Clastic Upland Lakes are vulnerable to hydrological manipulations which permanently lower the water levels and hasten successional processes, and those which prevent periodic dry-downs and hasten eutrophication. They are also vulnerable to various activities in the surrounding uplands. Land clearing and timber harvests on the adjacent uplands generally increase sedimentation rates and, therefore, successional processes. Residential, agricultural, and industrial development within a lake's drainage basin generally increases pollution levels and accelerates eutrophication, which could be extremely detrimental to fish and other aquatic organisms. Human-related manipulations and activities within the drainage basin must be adequately controlled to avoid detrimental repercussions to these important communities.

• Source: Florida Natural Areas Inventory and Florida Dept. of Natural Resources. 1990. Guide to the natural communities of Florida. Florida Natural Areas Inventory and Florida Dept. of Natural Resources, Tallahassee, FL. iv, 111 p.