Wetland Identification

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Wetland Identification

• Introduction to Coastal Management

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What is a wetland?

• Lands on which water covers the soil or is
  present either at or near the surface of the soil
  or within the root zone all the year or for
  varying periods of time during the year,
  including during the growing season.

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Wetland Definition

• Used by the US Army Corps of Engineers and
  Environmental Protection Agency
• Those areas that are inundated or saturated by
  surface or groundwater at a frequency and
  duration sufficient to support, and that under
  normal circumstances do support, a prevalence of
  vegetation typically adapted for life in
  saturated soil conditions. Wetlands generally
  include swamps, marshes, bogs, and similar areas.
  (EPA,40 CFR 230.3 and CE, 33 CFR 328.3)

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Wetland Definition

• Used by U.S. Fish and Wildlife Service, National
  Wetland Inventory Program
• Wetlands are lands transitional between
  terrestrial and aquatic systems where the water
  table is usually at or near the surface or the
  land is covered by shallow water. wetlands must
  have one or more of the following three
  attributes 1) at least periodically, the land
  supports predominantly hydrophytes, 2) the
  substrate is predominantly undrained hydric soil,
  and 3) the substrate is nonsoil and is saturated
  with water or covered by shallow water at some
  time during the growing season of each year.

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Cowardin Wetland and Deepwater Classification
System

• Marine
• The Marine System consists of the open ocean
  overlying the continental shelf and its
  associated high-energy coastline.
• Estuarine
• The Estuarine System consists of deepwater tidal
  habitats and adjacent tidal wetlands that are
  usually semi-enclosed by land but have open,
  partly obstructed, or sporadic access to the open
  ocean, and in which ocean water is at least
  occasionally diluted by freshwater runoff from
  the land.

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Cowardin Wetland and Deepwater Classification
System

• Riverine
• The Riverine System includes all wetlands and
  deepwater habitats contained within a channel,
  with two exceptions (1) wetlands dominated by
  trees, shrubs, persistent emergents, emergent
  mosses, or lichens, and (2) habitats with water
  containing ocean-derived salts in excess of 0.5.
• Lacustrine
• The Lacustrine System includes wetlands and
  deepwater habitats with all of the following
  characteristics (1) situated in a topographic
  depression or a dammed river channel (2) lacking
  trees, shrubs, persistent emergents, emergent
  mosses or lichens with greater than 30 areal
  coverage and (3) total area exceeds 8 ha (20
  acres).

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Cowardin Wetland and Deepwater Classification
System

• Palustrine
• The Palustrine System includes all non-tidal
  wetlands dominated by trees, shrubs, persistent
  emergents, emergent mosses or lichens, and all
  such wetlands that occur in tidal areas where
  salinity due to ocean-derived salts is below
  0.5. It also includes wetlands lacking such
  vegetation, but with all of the following four
  characteristics (1) area less than 8 ha (20
  acres) (2) active wave-formed or bedrock
  shoreline features lacking (3) water depth in
  the deepest part of basin less than 2 m at low
  water and (4) salinity due to ocean-derived
  salts less than 0.5.

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Wetland Characteristics

• Hydric soils
• Hydrology
• Hydrophytic vegetation

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Hydric Soils

• A hydric soil is a soil that formed under
  conditions of saturation, flooding, or ponding
  long enough during the growing season to develop
  anaerobic conditions in the upper part
• Chemical and biological oxygen demand (COD and
  BOD) rapidly exhaust oxygen in the soil
• The USDA has defined soil types, including hydric
  soils

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Hydric Soils

• All Histosols are considered hydric (except for
  folists)
• Soils in Aquic suborders and subgroups are
  considered hydric
• Soils somewhat poorly drained with the water
  table lt0.5 feet from the surface
• Poorly or very poorly drained soils with frequent
  flooding or poor permeability

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Field Indicators of Hydric Soils

• Histosols
• Histic epipedon
• H2S in mineral soils
• Aquic moisture regime
• Reducing soil conditions
• Gleyed soils immediately below A horizon
• Bright mottles immediately below A horizon
• Iron (reddish brown) and or manganese (black)
  concretions

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Hydrology

• Wetlands require permanent or periodic inundation
  or soil saturation at the surface of a week or
  more during the growing season
• These conditions create an anaerobic environment

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Field Indicators of Wetland Hydrology

• Inundation
• Soil saturation at 12 inches or less
• Watermarks
• Deposition of water-borne debris
• Deposits of water-borne sediment
• Drainage patterns within wetland
• Water stained leaves
• Morphological adaptations of plants

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Hydrophytic Vegetation

• 50 of the composition of the dominant plants
  must be obligate wetland species, facultative
  wetland species, and/or facultative species
• Obligate and facultative wetland species are the
  most reliable indicators of the presence of a
  wetland

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Hydrophytic Vegetation

• Plant classification
• Obligate Wetland (OBL)
• Facultative Wetland (FACW)
• Facultative (FAC)
• Facultative Upland (FACU)
• U.S. Fish and Wildlife Service has listing of
  wetland plant species

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Wetland Loss and Degradation

• Hydrological alteration
• Urbanization
• Marinas and boat use
• Industry
• Agriculture
• Silviculture
• Mining
• Atmospheric deposition

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Wetland Mitigation

• U.S. Army Corps of Engineers is obligated to
  require mitigation for any unavoidable impact on
  a wetland as a condition of permit approval
• Avoidance of mitigation is best course
• Costly and controversial
• Creates long-term liability for owner
• Serious exercise which must result in maintaining
  similar functions of wetlands
• Mitigation banking

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Measures of Mitigation Success

• Looks like a wetland
• Hydroperiod mimics natural systems
• Wetland plants colonize or volunteer
• Soils, physically and chemically, mimic natural
  wetlands
• Diversity, density, and biomass of animals is the
  same as natural systems