what is a wetland?

  • interface between uplands and aquatic habitat, a mix of both

  • aquatic habitat can include

    • ocean

    • estuary

    • rivers

    • lakes

    • ponds

    • wet areas

  • US Army Corps of Engineers

    • they handle wetlands because of navigability standards and DOI transportation of goods

    • their definition:

      • “Those area 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, or similar areas.”

    • Federal Manual for Identification and Delineation of Jurisdictional Wetlands (1989)

      • all 3 criteria for a jurisdictional wetland

        • soils hydric or waterlogged

        • soils how demonstrable evidence of hydrologic conditions associated with ponding or flooding

        • 50% of dominant plants (all strata) are wetlands plants

    • operational definition including hydrology, soil, and plants

  • regulation of discharges of dredge or fill material in the waters of US

    • having interstate or international commerce potential

    • includes navigable waterways, most lakes, ponds, sloughs, impoundments, wetlands, prairie potholes, ponds, etc.

  • also applies above headwaters of same thing

  • wetland soil is VERY fertile

  • USDA: food security act of 1985

    • any land farmed before 1985 is exempt from regulatory action relating to wetlands

  • US Fish and Wildlife Service

    • National Wetlands Inventory Program

  • order of plants in wetland (not wetland to wetland)

  • FEMA floodplain maps

    • indicates flooding potential

    • 100 year floodplain is key marker for most zoning (>1% chance of annual flooding, running water 1-3’ in depth, ZONE AE)

Hydric soils (it is all about Oxygen!)

  • 10,000 x slower diffusion in water than in air

  • plants

    • biochemical and structural adaptations

    • ex aerenchyma in non woody plants

  • on site indications of flooding (silt line, suspended rafted debris, etc)

  • water within 18 in of surface

  • Histic Epipedon

    • layer of black, organic muck on top of mineral soil

  • USDA

    • soil survey

    • hydric soils list

    • these indicate potential

  • Munsell system

  • charts

    • hue

    • value

    • chroma

Wetland plants

  • biochemically or structurally adapted to anoxic conditions

  • National List of Plants that Occur in Wetlands, by region

    • upland

    • facultative upland plant less than or equal to 33% of time in wetlands

    • facultative 34% to 66%

    • facultative wetland plant 67% to 99%

    • obligate wetland plant >99%

  • % of ALL dominant plants FAC, FACW, OBL >50%

    • tree

    • shrub

    • herb and/or vine

  • plant survey methods

    • percent cover most common

    • line-intercept

    • quadrat studies

    • time for sampling, key consideration

    • seasonal sampling time, another key consideration

Wetland Land Formation and Hydrology

  • three key processes

    • how did water get there?

      • precip

      • gravity

      • aquifers/springs

    • why does it stay wet?

    • how does it drain?