identifying hydric soils, a field trip will take in place to a local wetland
and samples will be taken.
indicators will be pointed out and will be asked to identify some from a
groups and have each group identify in which category the plants belong to.
recognize what type of wetland visited.
At the end of
the lesson, have a short fill in the blank test.
Background Information: The three indicators that a wetland is present is hydric soils, hydrophytes and hydrology.
Hydric soils are soils which are saturated, flooded, or ponded long enough
during the growing season to develop anaerobic conditions in the upper part
that favor the growth and regeneration of hydrophytic vegetation.
Whether there is water
present or not, nature tends to leave little clues that stand out from the
surrounding area. Examples are: water marks on trees, lichens, carpets of
moss growing on the ground floor.
Wetland plants are
categorized in three different types: emergent, submergent, and floating
Examples of emergent plants: cattails
Examples of submergent plants: sea grasses
Examples of floating leaves: lily pads
Given the diversity of
wetland environments, many classification schemes have been proposed and
utilized over the years. At the highest level these are the five wetlands:
Open ocean, continental shelf, including beaches, rocky shores, lagoons, and
shallow coral reefs. Normal marine salinity to hypersaline water chemistry;
minimal influence from rivers or estuaries. Where wave energy is low,
mangroves, mudflats or sabkhas may be present.
-- Deepwater tidal habitats with a range of fresh-brackish-marine water
chemistry and daily tidal cycles. Salt and brackish marshes, intertidal
mudflats, mangrove swamps, bays, sounds, and coastal rivers. Drowned coasts,
where supply of river sediment is insufficient to infill estuary basin.
-- Freshwater, perennial streams comprised of the deepwater habitat contained
within a channel. This restrictive system excludes floodplains adjacent to
the channel as well as habitats with more than 0.5‰ salinity.
-- This system includes inland water bodies that are situated in topographic
depressions, lack emergent trees and shrubs, have less than 30% vegetation
cover, and occupy at least 20 acres (8 ha). Includes lakes, larger ponds,
sloughs, lochs, bayous, etc.
-- All non-tidal wetlands that are substantially covered with emergent
vegetation--trees, shrubs, moss, etc. Most bogs, swamps, floodplains and
marshes fall in this system, which also includes small bodies of open water
(< 20 acres), as well as playas, mudflats and salt pans that may be devoid
of vegetation much of the time. Water chemistry is normally fresh but may
range to brackish and saline in semiarid and arid climates.