Transcript Fresh water environment

World Biomes
Fresh water
Freshwater
Rivers,
streams
Lakes,
ponds
Wetlands
Wetlands
• Bogs, swamps, and marshes are wetlands. All
wetlands have waterlogged soil. Bogs and swamps
are flooded, but a marsh is wet only part of the year.
Some wetlands are flooded with salty ocean water;
others are covered with fresh water from rivers and
lakes.
marsh
swamp
bog
Wetland distribution
• Wetland biomes are found all over the world. They are
often near lakes and rivers, but they also develop in
sunken areas of grassy plains.
Wetland climate
• Unlike some other biomes, wetlands do not have a
characteristic climate. They exist in polar, temperate,
and tropical zones, although usually not in deserts.
However, they are very sensitive to changes in
climate, such as a decrease in precipitation (rain,
sleet, or snow). The amount of precipitation and
changes in temperature affect the growth rate of
wetland plants. Some wetlands are seasonal, which
means that they are dry for one or more seasons of
the year.
Wetland soil
• Wetland soils are
known for their
wetness but they
should also be
known for their high
organic content.
Most wetland soils
have a higher
amount of organic
material than
terrestrial soils.
Wetland plants
• More than 5,000 species of plants live in or near
wetlands. Wetlands have high biological productivity
(the rate at which life forms grow in a certain period of
time).
• The kinds of plants that may be found in a wetland are
determined by several factors, especially the type of
soil and the quantity of water.
• Some plants grow only in water or extremely wet soil.
Other plants need moist but not saturated soil. When a
wetland dries up, the area fills with plants adapted to
life in dry habitats and can survive where other
wetland plants would wilt.
Pond Lily
Cattail
Marsh Purslane
Cypress swamp
Animals
• Wetlands have been called "biological supermarkets."
Besides animals that live there permanently, many
nonwetland animals visit for food and water.
• Wetland conditions make it necessary for the animals
that live there permanently to adapt in special ways.
Lungfish
Dragonfly
Bittern
Boat-billed Heron
Snipe
Leopard Frog
Swamp Tortoise
Rivers
• These are bodies of flowing water moving in one
direction. Streams and rivers can be found
everywhere—they get their starts at headwaters,
which may be springs, snowmelt or even lakes, and
then travel all the way to their mouths, usually another
water channel or the ocean. The characteristics of a
river or stream change during the journey from the
source to the mouth.
Distribution of Rivers
Conditions in Rivers
• The temperature is cooler at the source than it is at the
mouth. The water is also clearer, has higher oxygen
levels.
• Towards the middle part of the stream/river, the width
increases, as does species diversity—numerous
aquatic green plants and algae can be found.
• Toward the mouth of the river/stream, the water
becomes murky from all the sediments that it has
picked up upstream, decreasing the amount of light
that can penetrate through the water. Since there is
less light, there is less diversity of flora, and because
of the lower oxygen levels, fish that require less
oxygen.
River plants
• In fast streams and rivers many plants have special
structures that keep them from being carried away by
the water. Some aquatic plants have strong roots that
keep them anchored securely, while others have
stems that bend easily with the movement of the
water. Certain mosses are able to cling to rocks.
River plants
Algae from Mississippi
River animals
• In fast moving waters animals that have to hold onto
rocks and the bottom may have suction-cup like
structures on their bodies.
Anaconda and Cayman
Black River Turtle
Red-Bellied Piranha
Gavial
Lakes
• These regions range in size from just a few square
meters to thousands of square kilometres. Scattered
throughout the Earth. Many ponds are seasonal,
lasting just a couple of months while lakes may exist
for hundreds of years or more. Ponds and lakes may
have limited species diversity since they are often
isolated from one another and from other water
sources like rivers and oceans.
Distribution of Lakes
Conditions in Lakes
• The zone, which is closet to the shore is host to a wide
variety of species due to its warm, shallow
environment. Various species of invertebrates,
crustaceans, plants and amphibians thrive in this
environment, and in turn provide food for predators
such as birds, reptiles and other creatures inhabiting
the shoreline.
• The open water near the surface of a lake or pond, is
home to a variety of phytoplankton, and zooplankton,
which play an important role in the food chain. Several
species of freshwater fish such as bass and lake trout
can also be found this area, mainly feeding on insects
and plankton.
• The deeper region of a lake is shrouded in darkness,
and serves as a repository for dead plankton, and is
inhabited by creatures which feed mostly on decaying
organisms.
Lake plants
• Underwater plants need to stay close to the water's
surface so sunlight can reach them. Some freshwater
plants, such as water lilies, grow flowers and leaves
that float on the water's surface.
Victoria
Lake animals
• Many types of animals live in ponds because they are
not in danger of being swept away by a current.
Insects, birds, turtles, frogs, and fish are some of the
animals you can find in ponds and lakes.
• In regions with colder climate some animals have to
hibernate during winter.
Common Carp
White Pelican
Anodonta
Great Pond Snail
People I
• Without freshwater biomes we would not be alive.
Freshwater ecosystems are important because they
provide us water for drinking; energy and
transportation.
• Dams may provide pollution-free energy, and create
lakes for people to enjoy, but they can also damage
the environment. Salmon are a species that use rivers
to spawn, and are often hurt by dams.
• Wetlands are also an important type of freshwater
ecosystem. They may be soggy and stinky, but they
provide critical habitat for tons of plants and animals,
help clean our water, control floods, and provide food
for humans.
• By fertilizing the lawn with chemicals and allowing our
cars to drip nasty oils and fluids we are polluting
freshwater biomes. The rain carries these pollutants
into rivers, streams, lakes and ponds.
People II
River dam