Download Yr 7 ecosystems Revision sheet An ecosystem is a community of

Yr 7 ecosystems Revision sheet
An ecosystem is a community of plants
and animals that interact with the living
(biotic) and non-living (abiotic)
environment
An example of an animal interacting
with its environment is a wolf
Food webs are diagrams that show how
energy is moved around an ecosystem. The
arrow goes in the direction of the energy flow.
In this diagram a fox eats a bird for energy.
Therefore the arrow in the diagram points from
the bird to the fox (Bird Fox).
Interactions with biotic factors
•Eating a rabbit
•Being eaten by a bear
•Mating with another wolf
Interactions with abiotic factors
•Sleeping in a cave
•Drinking water from a river
•Struck by lightning
A sand dune by the sea is an ecosystem. It provides a place for plants
and animals to live. The shape of it protects places from strong winds,
waves and flooding. They are formed when an object like a piece of drift
wood or even a dead marine animal or bird is left on the beach. The
object will trap sand as it is blown across the beach. Marram grass can
grow in salty area so may grow on the pile of sand that we call a dune.
Its roots will hold the sand together (we say they stabilise it) Over time
organic matter (dead grass/poo/dead animals will mix with the sand, rot
and create soil. The soil allows other plants and trees to grow and more
animals will be able to live there
Rainforest ecosystems
There are more interactions going on in
a rainforest ecosystem than any other
ecosystem on Earth. In fact, an
ecosystem this large is called a Biome.
The weather in a rainforest is a result
of the very hot weather around the
equator and also due to the huge
amount of transpiration that happens.
Transpiration is the process of water in
the trees being released into the air in
the hot sunny weather. This warm wet ai
rises rapidly into the sky throughout the
day. It cools, condenses and clouds
form. Then the rain follows! We call this
convectional rainfall.
If we remove the trees there will be less
transpiration and therefore less rain. We
won’t be able to call it a rainforest
anymore.
Relief RainfallRelief rainfall is where rain is caused
by the height of the land.
Adaptations in a rainforest
Big Buttress roots grow outwards
to capture nutrients that are
released as dead matter on the
forest floor rots away. There’s no
point in sending roots down deep
into the earth; the nutrients have
been washed away-a process we
call leaching.
Deforestation-this means
destroying a forest by removing
the trees. Think how many
species in a rainforest have an
interaction with a tree. Trees
are homes, hiding places, food,
hunting grounds, ladders and
shelter for the animals in a
rainforest. Can anything survive
if the trees are removed?
Big Buttress
roots
grow outwards
Before
and after
deforestation
to capture nutrients that are
released as dead matter on the
forest floor rots away. There’s no
point in sending roots down deep
into the earth; the nutrients have
been washed away-a process we
call leaching.
Top of a mountain= high relief
Bottom of a valley= low relief
Warm wet air is blown towards hills and mountains. The
air is forced upwards (it can’t go through the hill!).
As the warm wet air rises it cools. It is now cool wet air.
The water in the air cools, condenses and clouds form.
The clouds get heavy and it rain/snows. This is called
precipitation. The air carries on and is now cool and
drier. A rainshadow effect happens to places on the
leeward side of the mountains. The air isn’t wet enough
to bring them rain so their climate is much drier.
Note-if you moved to Manchester you would notice that
they have wetter weather than us. They live on the
wetter windward side; we live on the drier leeward side
of the Pennine Hills.
You need to know at least three
reasons why rainforests are
being cut down. Can you
unscramble them?
1.
FRIAMGN
2.
GOLGING
3.
RIFE DOWO
Before and after deforestation
Raising awareness through
campaigning
Raising awareness through
campaigning
Relief rainfall
Helping to regenerate (re-grow) an ecosystem. Rainforests are
difficult. There are things that can be done but it’s difficult and the people there are hard to persuade because they are poor and want
to use the forest to get richer. Sand dunes in rich countries can be regenerated by using old xmas trees to slow wind energy and
build up deposits of sand. We can replant indigenous species (ones that belong there) which can be difficult or we can plant species
that we know will grow well but don’t naturally belong there. Is this OK? Can you think of any problems with introducing a new
species into a place? Try googling ‘history of grey squirrels in the UK’ or ‘Rabbits in Australia’ for an example