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LAKES AND PONDS
ECOSYSTEM
Presentor:
Evardone, Hergie B.
BEED-Math
Ed. Tech. 2
Ponds and Lakes
range in size from just a few square
meters to thousands of square kilometers.
ponds may be seasonal, lasting just a
couple of months (such as sessile pools).
lakes may exist for hundreds of years or
more.
may have limited species diversity since
they are often isolated from one another
and from other water sources like rivers
and oceans.
Most ponds and lakes have outlet streams
Formation of Lakes and Ponds:
Lakes and ponds are formed through a variety of
events, including glacial, tectonic, and volcanic activity.
Most lakes and ponds form as a result of glacial
processes. As a glacier retreats, it may leave behind an
uneven surface containing hollows that fill with water.
Some of the oldest lakes and ponds (more than three
hundred thousand years old) were formed by tectonic
activity related to movement of Earth's crust. For
example, Lake Baikal in Siberia formed from the
movement of tectonic plates and is the largest
freshwater lake by volume in the world.
Volcanic activity can also lead to lake and pond
formation. For example, the collapse of a volcanic cone
of Mount Mazama in Oregon led to the formation of
Crater Lake, the seventh deepest lake in the world.
Lake Baikal
Crater Lake , Oregon
Ponds and Lakes
Temperature varies seasonally.
During summer the temp. is from
4°C near the bottom to 22°C at the
top.
During winter the temp. is from 4° C
while the top is 0° C (ice).
during the spring and fall seasons is
a mixing of the top and bottom
layers resulting in a uniform water
temperature of around 4° C.
Ponds and Lakes
divided into four different
“zones” determined by depth and
distance from the shoreline
• littoral zone
• limnetic zone
• profundal zone
• Photic zone
• Benthic zone
Littoral Zone
warmest since it is shallow and can absorb
more of the Sun’s heat
sustains a fairly diverse community, which can
include several species of algae (like diatoms),
rooted and floating aquatic plants, grazing
snails, clams, insects, crustaceans, fishes, and
amphibians
the egg and larvae stages of some insects are
found in this zone
vegetation and animals living in the littoral
zone are food for other creatures such as
turtles, snakes, and ducks
Limnetic Zone
near-surface open water surrounded by
the littoral zone
well-lighted (like the littoral zone) and is
dominated by plankton, both
phytoplankton and zooplankton
plankton are small organisms that play a
crucial role in the food chain – most life
would not be possible without them
variety of freshwater fish also occupy this
zone
Profundal Zone
much colder and denser than the
other two
little light penetrates all the way
through the limnetic zone into the
profundal zone
Plankton have short life spans—when
they die, they fall into the deep-
water part of the lake/pond
animals are decomposers
Photic zone
Primary production in the photic zone is influenced by
three major factors—nutrients and light, which are
essential for photosynthesis, and grazing pressure,
the rate at which the plants are eaten by herbivores.
Nutrients, especially phosphate and nitrate, are often
scarce in the photic zone because they are used up
quickly by plants during photosynthesis. External
inputs of nutrients are received through rainfall,
riverflow, the weathering of rocks and soil and from
human activities, such as sewage dumping. Nutrient
enrichments also occur through internal physical
processes such as mixing and upwelling that
resuspend nutrients from deeper volumes of the water.
Benthic Zone
The area of the sea bottom.
Benthic, a term meaning bottom is the name of the
ocean zone ranging from the deepest parts of the
ocean to the tidal affected areas. The most productive
region of the benthic zone is the area over the
continental margin, which is unaffected by the tides.
Many groups and varieties of animals live here, a few
are worms, sea pens, crustaceans, stars, and
protozoa.
The life in this zone is mostly made up of bottom
dwellers which get most of their food from dead and
decaying organisms. Therefore most of the organisms
in the benthic zone are scavengers because they
depend on dead flesh as their main food source.
LAKES
ECOSYSTEM
Lakes Ecosystem
A lake is bigger than a pond, and is too deep to
support rooted plants except near the shore.
Some lakes are big enough for waves to be
produced.
Lakes may exist for hundreds of years or more.
Lakes are often classified as oligotrophic or
eutrophic, depending on the amount of organic
matter produced.
Clasification of Lake
Oligotrophic lakes are deep, nutrient-poor
lakes in which the phytoplankton is not very
productive. The water is usually clear; the
profundal zone has a high oxygen concentration
since little detritus is produced in the limnetic
zone to be decomposed.
Eutrophic lakes are shallow, nutrient-rich
lakes with very productive phytoplankton. The
waters are usually murky due to large
phytoplankton populations and the large
amounts of detritus being decomposed may
result in oxygen depletion in the profundal zone
during summer.
Oligotrophic lake Eutrophic Lake
Examples of lakes
Taal volcano lake
Mitchigan lake
Silver lake Lake lamonia
Grasmere lake
Layers of lake separated by density gradient.
1. Epilimnion
the top-most layer in a thermally stratified lake.
It is warmer and typically has a higher pH and
dissolved oxygen concentration than the
hypolimnion.
It typically becomes turbulently mixed as a
result of surface wind-mixing.
Free to exchange dissolved gases (ie O2 and
CO2) with the atmosphere.
It contains the most phytoplankton. As they grow
and reproduce they absorb nutrients from the
water, when they die they sink into the
hypolimnion resulting in the epilimnion becoming
depleted of nutrients.
2. Thermocline
(sometimes metalimnion) is a thin but distinct
layer in a large body of fluid (e.g. water, such as an
ocean or lake, or air, such as an atmosphere).
Temperature changes more rapidly with depth than
it does in the layers above or below.
Thermoclines may be a semi-permanent feature of
the body of water in which they occur, or they may
form temporarily in response to phenomena such
as the radiative heating/cooling of surface water
during the day/night.
Factors that affect the depth and thickness of a
thermocline include seasonal weather variations,
latitude, and local environmental conditions, such
as tides and currents.
3. Hypolimnion
The hypolimnion is the dense, bottom layer of
water in a thermally-stratified lake. It is the layer
that lies below the thermocline.
Typically the hypolimnion is the coldest layer of a
lake in summer, and the warmest layer during
winter. Being at depth, it is isolated from surface
wind-mixing during summer, and usually receives
insufficient irradiance (light) for photosynthesis to
occur.
In deep, temperate lakes, the bottom-most
waters of the hypolimnion are typically close to
4°C throughout the year. The hypolimnion may
be much warmer in lakes at warmer latitudes.
Types of Lakes:
1. Holomictic lakes
2. Monomictic lakes
3. Dimictic lakes
4. Polymictic lakes
5. Meromictic lakes
6. Amictic lakes
1. Holomictic lakes
are non-meromictic lakes (i.e., at some
time during the year, the water in
holomictic lakes will have a uniform
temperature and density from top to
bottom, allowing the lake waters to
completely mix).
Although the permanent ice-cover
of amictic lakes prevents mixing, they are
also regarded as being holomictic.
2. Monomictic lakes
are holomictic lakes that mix from
top to bottom during one mixing
period each year. Monomictic lakes
may be subdivided into two types:
1. Cold monomictic lakes
2. Warm monomictic lakes
1. Cold monomictic lakes are lakes that
are covered by ice throughout much of
the year. These lakes are typical of cold
climate regions (e.g., much of the
arctic).
2. Warm monomictic lakes are lakes
that never freeze, and are thermally
stratified throughout much of the year.
These lakes are widely distributed from
temperate to tropical climatic
regions.One example is South
Australia's Blue Lake, where the change
in circulation is signaled by a striking
change in colour.
BLUE LAKE
Mono Lake
Dal Lake
Okanagan Lake
3. Dimictic lakes
Dimictic lakes are holomictic lakes that
mix from top to bottom during two
mixing periods each year. During winter
they are covered by ice. During summer
they are thermally stratified, with
temperature-derived density differences
separating the warm surface waters
(the epilimnion), from the colder bottom
waters (the hypolimnion).
Typical mixing pattern for
a dimictic lake.
4. Polymictic lakes
are holomictic lakes that are too shallow
to develop thermal stratification; thus,
their waters can mix from top to bottom
throughout the ice-free period.
Polymictic lakes can be divided into cold
polymictic lakes(i.e., those that are ice-
covered in winter), and warm
polymictic lakes (i.e., polymictic lakes
in regions where ice-cover does not
develop in winter).
5. Meromictic lake
A meromictic lake has layers of water
that do not intermix.In ordinary,
"holomictic" lakes, at least once each
year there is a physical mixing of the
surface and the deep waters.This mixing
can be driven by wind, which creates
waves and turbulence at the lake's
surface, but wind is only effective at
times of the year when the lake's deep
waters are not much colder than its
surface waters.
Lac Pavin in France is a meromictic crater lake
1. Amictic lakes
Amictic lakes are holomictic lakes
that are permanently ice-covered.
They are restricted to very cold
climates (Arctic, Antarctic, and
alpine).
Lake Hoare
Freshwater: biological communities of
lakes
PONDS
ECOSYSTEM
Ponds Ecosystem
A pond is a small, shallow body of fresh,
standing water in which relatively quiet
water and extensive plant growth throughout
are common characteristics.
The amount of dissolved oxygen may vary
greatly during a day. In really cold places, the
entire pond can freeze solid.
Water temperature is fairly even from top to
bottom and changes with air temperature.
Types of ponds
Cypress Ponds
Bog Ponds
Meadow-Stream Ponds
Mountain Ponds
Farm Ponds
1. Cypress Ponds
which are commonly found in the central
or lower Mississippi Basin and along the
coastal plain of the Southeastern United
States. Their waters are described as
being brownish in color, and many dry
out during parts of the year. Willows, bay
trees mixed with cypress trees, grows
along the shore and are often found out
in the waters.
Cypress Pond on the Conecuh River near River Falls, Alabama
2. Bog Ponds
(2) Bog Ponds are often found in the
moist temperature regions of North
America. The water is highly acidic
and often muddy. Alders grow
profusely on the shore and cedar
trees dominate the high ground.
Thick beds of sphagnum extend
outward from the shore and floating-
leaf plants usually cover the surface.
3. Meadow-Stream Ponds
form where streams widen and the
speeds of its currents slow down
tremendously. The shallow part of
the pond usually has an abundance
of pondweeds, cattails, stoneworts
and other plants with emergent
leaves. They also have plants with
floating leaves on the surface of the
water, such as lilies and water
shields.
4. Mountain Ponds
which are often formed by glaciers, are
another type of pond. The bottoms of
these ponds range from being rocky,
graveled or muddy. Most of the time
Mountain Ponds have ice in them and they
usually dry up at some point during the
summer. Sedges grow along its margins.
In spite of the pond’s short summer
season, a variety of animals and plants
live in these icy waters.
5. Farm Ponds
are man-made ponds built to help keep
the farmlands fertile. Farm ponds are at
least three feet deep at the shoreline in
order to prevent plant growth that would
lead to the early succession of the pond. It
should also have a spillway to control the
water level. Farm ponds usually become
abundant in fish, and are usually good
waters for swimming and boating. They
should also fill from seepage, not from
another stream which would fill the basin
of the pond with silt and eventually kill the
pond.
Examples of ponds
Plants and Animals in Lakes and
Ponds Ecosystem:
Plants: In general, these are usually the marginal zone of
emergent plants, the zone of floating plants, and the zone of
submerged plants. In older and more productive ponds, algal
growths often become conspicuous.
Animals: Insects usually are the most abundant and have the
greatest diversity of species. Of the other invertebrates, the
protozoa, rotifers, crustaceans, and snails are most important.
Among the vertebrates, amphibians (e.g., frogs) are considered by
some as the most important group. Fish may be reduced to minor
densities (except in larger, permanent ponds) compared to lakes.
Pond animals, particularly those of temporary ponds, are largely
composed of species which may have a part of their life cycles out of
water (e.g., flying insects). Surface-film animals and those that come
out to the surface for
breathing are often abundant.
VEGETATION IN LAKES AND PONDS
ECOSYSTEM
Animals in Lakes and Ponds
Bitterling Bullfrog Common Carp Green and Gold
Bell Frog
Great Crested Grebe Largemouth Bass
Great White Pelican
Zambesi Softshell
Platypus
Lake Trout
Functions:
Lakes and ponds typically contain a diversity of organisms that perform
different ecological functions.
Lakes and ponds are an important source of fresh water for human
consumption and are inhabited by a diverse suite of organisms. It supplies
us [humans] with drinking water and water for crop growing.
Water has a high capacity for heat and earth is mostly covered with water, so
the temperature of the atmosphere is kept fairly constant and able to support
life.
Plankton which account for most of the photosynthesis on Earth found in
lakes, ponds and oceans. Without, there might not be enough oxygen to
support such a large world population and complex animal life.
We fish from the ponds and we often eat the fish we catch. Most of the time
our water comes from the lakes and ponds, but purified.
Environmental Problems:
Freshwater biomes have suffered mainly from
pollution.
Runoff containing fertilizer and other wastes,
and industrial dumpings enter into rivers,
ponds, and lakes tend to promote abnormally
rapid algae growth.
When algae die, dead organic matter ends up
in the water. This makes the water unusable,
and it kills many of the organisms living in the
habitat.
Possible Solution:
Pond Aeration
To restore a pond or lake to a healthy condition, we
must restore the natural processes that allow them to
assimilate the nutrient load that it receives. Ideally,
nutrient inputs should be reduced or eliminated
wherever possible. Understanding our limited ability to
accomplish this task, we must then supplement and
support natural assimilation of the nutrient load as it
exists.
Only use phosphorus-free fertilizers on lawns.
Preventing nutrients from flowing down storm sewers
is a good way to prevent pollution.
REFERENCES
www.google.com
www.yahoo.com
1. ↑ Biggs J., Williams P., Whitfield M., Nicolet P. and Weatherby, A. (2005).
15 years of pond assessment in Britain: results and lessons learned from the
work of Pond Conservation. Aquatic Conservation: Marine and Freshwater
Ecosystems 15: 693-714.
2. ↑ http://www.ramsar.org/ris/key_ris_e.htm
3. ↑ Biggs J., Williams P., Whitfield M., Nicolet P. and Weatherby, A. (2005).
15 years of pond assessment in Britain: results and lessons learned from the
work of Pond Conservation. Aquatic Conservation: Marine and Freshwater
Ecosystems 15: 693-714.
4. ↑ Céréghino, R., J. Biggs, B. Oertli, and S. Declerck. 2008. The ecology of
European ponds: Defining the characteristics of a neglected freshwater habitat.
Hydrobiologia 597:1-6.
5. ↑ Oxford English Dictionary
6. ↑ But mere may be thought a better term for this.
7. ↑ http://www.mainelegislature.org/legis/statutes/38/title38sec436-a.html
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