Still Water Habitats
Many odonates inhabit still water. Still water habitats include bogs
and fens, as well as ponds
and lakes that are relatively stable bodies of water
even if they do have some flow. Marshes and
swamps also may have some flow but are usually considered
still water. There are also a number of man-made habitats such as
retention basins and
borrow ponds.
 LAKE
A lake is a large body of fresh water surrounded by land. Lakes may be
either naturally formed or man-made. Lakes are regularly supplied with an
inflow of water; in most, the water flows out again. A number of water plants
live under the surface of lakes, usually near the shoreline; the middle is generally
too deep to support rooted plants. The depth of a lake determines its plant,
animal and insect life. Deep lakes, with a layer of cold water at the bottom,
often do not contain enough microscopic food or vegetation to nurture many forms
of life. Shallow lakes, on the other hand, are rich in algae and insects.
The shallows at the lake edge are often home to the same species found at ponds.
Large lakes may also support some of the Clubtails typically found along large rivers.
 POND
A pond is generally a small body of water shallow enough to support rooted plants.
Water temperature is fairly even from top to bottom and changes with air temperature.
There is very little wave action and the bottom is generally covered with mud or
debris. Plants such as water lilies can be seen on the surface with different
perennial grasses and plants growing along its edges. Ponds usually do not
dry up during the summer months (except in severe drought) and often do not support
fish. Ponds are often the home for numerous members of the Skimmer family and an
assortment of Bluets and Forktails.
 Farm Pond - manmade
Especially in midwestern and western states, farm ponds dot the landscape. Since
these water features are constructed primarily for use by livestock, they tend to
be deeper and less vegetated than more natural ponds. Many are stocked with
a variety of fish. With their lack of vegetation they generally support only
a limited number of hardy species such as skimmers and a few common damselflies.
 BOG
A very old lake with no inlet or outlet. It has no underground springs
of fresh water to feed it. These systems, whose only water source is rainwater,
are usually found in glaciated areas of the northern United States and Great Lake
regions and also in the southeast. Bogs are low in the nutrients needed for most
plant life. Because of the acid water and lack of oxygen, fish and many other
forms of aquatic life are generally absent. Usually a form of moss known as
sphagnum grows thick and forms an unstable floor (SEE
CAUTIONS) covered with floating plants. Some bogs can support blueberries,
cranberries and sundews and may have a few carnivorous plants. Bogs are formed in
two ways, either by sphagnum moss growing over a lake or ponds slowly filling it,
or sphagnum moss blankets forming over dry land preventing water from leaving the
surface.
 FEN
A fen is a type of peatland with nutrient-rich waters and is found primarily
along the edges of lakes and rivers or the perimeters of bogs. Fens, unlike
bogs, have a continuous source of ground water rich in magnesium and calcium feeding
into them, making the water less acidic. Due to the low acidic content they
have higher nutrient levels and can support more grassy plants than a bog, showing
an abundance of sedges, reeds and rushes and carnivorous plants such as the pitcher
plant inhabiting the surface, whereas in bogs, the primary production is that of
mosses. Fens like bogs, tend to occur in glaciated areas of the northern United
States.
MARSHES
A marsh is a wetland that remains saturated at least half of the year.
The water level in a marsh varies from season to season. A marsh generally
does not have very deep water. It is usually covered by grasses, rushes and
cattails and is generally treeless and open. Marshes can be found in both
freshwater areas as well as saltwater areas.
 Freshwater Marsh
Freshwater marshes are usually low-lying non-tidal open areas near creeks,
streams, rivers and lakes. Usually water is flowing slowly through the marsh.
The water level usually ranges between one to six feet deep for most of the year
but may vary with the seasons. Flooding occurs in times of high rainfall,
and drawdown occurs during dry periods, often exposing matted vegetation or mud.
This waterlogged land supports many low-growing plants like grasses and sedges;
there may be a few trees in freshwater marshes, but for the most part it is dominated
by cattails, sawgrass, water lily, spikerush and pickerel weeds.
 Saltwater Marsh
Saltwater marshes are the transitional waters between the freshwater
of the rivers and the saltwater of the sea. They are areas of low ground that
are subject to daily flooding by saltwater tides. Usually there is a matrix
of interconnected shallow natural channels that aid tidal flow. They are found
near the coastlines in coves and bay areas protected from the destructive force
of the surf. These marshes are generally dominated by perennial grasses such
as cordgrass, saltgrass, cattails and pickerel weed. Some of the soils are
soft and will not support the weight of a man or large animal.
Brackish Marsh
Brackish Marshes occur along tidal tributaries; a transition between salt marshes
and tidal fresh marshes. They are irregularly tidally flooded, making them with
a lower salt content. The brackish marsh is usually dominated by perennial
grasses such as cordgrass, black needlerush, sawgrass and sedges. The soils
of these marshes are generally poorly drained and often have standing water atop
peat accumulation. Not too many odonates occupy these habitats. A few
species of Gliders, Dashers and Meadowhawks may be visitors to these areas
along with Forktails.
SWAMPS
Swamps are warm wet areas dominated by woody plants. Swamps vary in size
and occur in either freshwater or saltwater floodplains. They may have standing
water year-round or for only part of the year. In order for a wetland to be considered
a swamp, it needs to have at least 30% tree cover. There are many different
types of swamps, and generally swamps are named after the different types of trees
that dominate. Below are just a few found throughout the United States.
 Cypress Swamp
Plant growth is abundant in any swamp, but in cypress swamps it is overwhelming.
The towering cypress trees, often standing in water, are draped with vines and covered
with Spanish Moss, ferns, orchids, and other air loving plants. The water
level of most cypress swamps fluctuates dramatically throughout the year, exposing
the peat floor for weeks to months at a time. Generally the trees in the deep
soil at the center grow taller than those on the outside. Atop the still water,
duckweed or water lettuce may grown in a vivid green slick. Alligators may
bask on the banks or lie half-submerged in water in many cypress swamps in company
with harmless and venomous snakes. (SEE CAUTIONS)
 Wooded Swamp
A wooded swamp is actually a small forest which is often covered by water.
The soil is moist during the growing season and dry during the summer. They
are usually inundated with floodwater from nearby rivers and streams. A swamp
can be as deep as several feet of slow moving or standing water. The highly
organic soils of these swamps form a thick, black nutrient-rich environment for
the growth of water loving trees such as elm, maple, cedar, oak and balsam trees.
Wooded swamps not only contain high hardwoods but also shrub-size species, such
as dogwoods and alder species typically found in shrub-swamps. The ground
cover generally consists of ferns, sedges and a variety of grasses.
 Mangrove Swamp
Mangrove swamps are easily recognized habitats along tropical and subtropical
coastlines and brackish estuaries and deltas, where freshwater meets saltwater and
are known for their impenetrable maze of wood vegetation. These flats are
found mostly along bays and inlets protected from heavy waves. A dense canopy
of Mangrove Trees dominate this wetland due to their ability to survive in both
salt and freshwaters along with a variety of salt loving shrubs and plants.
These swamps are constantly replenished with nutrients transported by freshwater
runoff from the land and flushed by the ebb and flow of the tides, supporting a
host of animal, plant and insect life.
 VERNAL POOL - TEMPORARY FRESHWATER
Vernal pools are extremely scarce wetland habitats occurring only where certain
soil conditions exist. Vernal pools can range in size from small puddles to
shallow size lakes. In late summer, fall and early winter, they appear as
dry, dusty indentations mostly devoid of vegetation and life. Then, in late
winter, a spectacular transformation takes place as these depressions fill up with
rain water, high numbers of endangered, rare and sensitive species of plant, animal
and insects appear in and around the pools, many of which can only be found in this
system.
 RETENTION BASIN - MANMADE,
OFTEN TEMPORARY
Human made ponds created with soil and rock. These are temporary and during
droughts may dry up. Like vernal pools, retention basins may fill up and dry
up several times a year depending upon the amounts of precipitation and depth of
the pool.
BORROW PIT - MANMADE
A pond or lake created by excavation for construction materials, often found along
major roadways. The depth varies based on the amount of material removed from
the area. Borrow pits are frequently stocked with fish and many are managed by state
and local governments as designated wildlife areas.
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