Wet Organic Soil Flats and Depressions

Description

Shrub bog is found on the edge of swamps, in stream head drainage seeps, and on flat, poorly drained divides between rivers. Shrub bogs occur in areas of poor internal drainage that typically have highly developed organic soils.

Community dynamics are driven by hydrology, especially hydroperiod, accumulation of organic soils, and periodic fire. This site has a long hydroperiod with the water table at or near the soil surface 6 to 12 months of the year. Periodic low intensity surface fire impacts species composition and productivity, but intense fire during droughty conditions can consume significant volumes of organic soil. Periodic low intensity surface fires favor pond pine, but the absence of fire favors bay hardwoods and slash pine. Intense fire can significantly lower soil surface elevation and may cause a state transition with prolonged periods of inundation.

(FNAI, 2010; Schafale et al., 1990; Sharitz et al., 1982)

Submodel

Submodel

Description

This is a relatively wet site within a landscape with a persistent and nearly ubiquitous shallow water table across the MLRA. Historically, these sites have been drained frequently to support a variety of land uses including forestry, agriculture, and development. This drained state is included in this STM because this state exists widely today across the landscape. Drainage of wetlands today is significantly regulated. NRCS is required to consider impacts to wetlands according to Federal laws including, but not limited to, the Clean Water Act, the Wetland Conservation provisions of the Food Security Act of 1985, and State, Tribal, and local laws. It is the policy of NRCS to protect and promote wetland functions and values in all NRCS assistance (National Environmental Compliance Handbook (NECH) 610.36).

Submodel

Description

After land on this site has been drained, it is impossible to return fully to reference conditions that existed at that location prior to drainage, especially at locations that remained under active drainage management for long periods of time. Drained organic soils will have a lower soil surface elevation, and thinner organic horizons, than prior to drainage. Restoration efforts might include blocking and removing drainage structures, revegetation, and reintroduction of periodic fire, but redevelopment of organic soil surface elevations will take profoundly long periods of time to achieve, if ever.

Submodel

Description

Any community on this site that has become salinized by the impacts of salt water inundation or intrusion. Saltwater intrusion is the movement of saltwater into freshwater systems. The process occurs mostly by lateral flow into areas adjacent to coastal waters or ditch systems that connect saltwater bodies. These ditch systems are designed to drain freshwater off of a site, but sea level rise and extreme tidal events push saltwater up these ditch systems and expose more of the landscape to salinization processes. Salinization can also occur as storm surge and/or extreme high tides push saltwater flooding and inundation over the top of these terrestrial freshwater systems.

Submodel