Download Importance of Wetlands: Water Filtration

Lesson Essential Question
1. What is a wetland?
2. Why are wetlands important
to their ecosystem?
What is a wetland?
Water Classification
• Wetlands are areas that are
covered by water or have
waterlogged soils for long
periods during the growing
season.
• Plants growing in wetlands are
capable of living in saturated
soil conditions for at least part of
the growing season.
• Sometimes may be
unrecognizable as these areas
will dry out.
• Wetlands are found from the
tundra to the tropics and on
every continent except
Antarctica.
What is a wetland?
•
There are three characteristics that describe a
wetland:
1. Hydrology
– There must be water at or near the surface of the
land for a designated amount of time.
2. Soils
– Must be hydric or saturated with water to create an
anaerobic (oxygen-free environment).
3. Plants
– Must be “wetland plants,” meaning that they require
lots of water and the anaerobic conditions that the
hydric soil creates. (Smith & Smith, 2001)
Hydrology
is at the surface or
within the soil root
zone during all or
part of the growing
season
Hydric Soil Classification
• Soils are
characterized by
frequent, prolonged
saturation and low
oxygen content,
which lead to
anaerobic chemical
environments where
reduced iron is
present.
Hydrophylic Plant
Classification
• Plants adapted for
growing in standing
water or saturated
soils, such as moss,
sedges, reeds,
cattail and
horsetail, rice,
mangroves,
cypress,
cranberries, etc.
United State and
Wetlands
Importance of
Wetlands: Hydrologic
•Long term and short
term water storage
– Wetlands protect land from
damage caused by flooding,
storms and tidal damage
Importance of Wetlands: Water
Filtration
•Wetlands remove nutrients
from surface and ground
water by filtering and by
converting nutrients to forms
that won’t harm the
environment
Importance of Wetlands:
Habitat
• There are a
number of
plant and
animal species
that can only
survive in a
wetland
ecosystem
What happens when wetlands are
destroyed?
• Destruction of wetlands can cause many
problems such as:
– Increased floods
– Water quality problems
– Population decrease in plants and animals
that live in wetlands
Can builders destroy wetlands?
• Section 401and 404 of the Clean Water
Act require developers that are going to
destroy a wetland to do three things:
– Avoid changing wetlands when possible
– When a wetland is impossible to avoid, they
must do as little damage as possible.
– If a wetland is destroyed, they must rebuild a
wetland in another place unless they pay into
a special fund to restore streams and
wetlands.
Wetland
Improvements
•Wetland
Restoration
•Wetland
Creation
•Wetland
Enhancement
Wetland Restoration
• A degraded
wetland or former
wetland is
returned to its
previous
condition as
much as possible
Wetland Creation
•A nonwetland
area is
converted
into a
wetland
Wetland Enhancement
•A function
of the
wetland is
improved
upon