The Living World revision summary

1. Key Areas Ecosystems
Small scale
ecosystem
Ecosystems: A community of animals, plants and micro-organisms, together with the habitat
where they live.
Pond ecosystems
Component Changes
An addition or loss to an ecosystem can affect the entire food web.
Large scale
ecosystems
Global ecosystem distribution and characteristics
The Living World
Biotic (living) links: E.g. Animals eating plants. Abiotic (non-living) links: Sunshine for photosynthesis.
Producers: Plants using sunlight for photosynthesis
and take in nutrients from the soil.
Primary consumers: Plant eating insects and
animals called herbivores (e.g. Tadpoles).
Secondary consumers: Eat primary consumers e.g.
Stickleback).
Top consumers: Hunt other animals (carnivores
or herbivores).
Decomposers: Organisms (e.g. Bacteria/fungus) that break down dead organic matter (dead animals/leaves).
• The loss of a producer (algae) will affect the rest of the food web. Tadpoles will lose their food supply and
decline in numbers, this in turn will decrease the numbers of perch as tadpoles are part of their diet. This
could lead to decreases in the top predators (pike and otters) who eat perch.
• Human influence such as litter can lead to a decrease in top predators such as herons (as they choke on
litter), This could lead to an overpopulation of frogs, a decrease in their food (insects) and so an increase
in pond plants such as algae. Too much algae in the water can starve the pond of oxygen, killing other
water species. This is called eutrophication.
Polar & tundra
Mediterranean
Tropical Rainforests
Deciduous Forests
Deserts
Savanna grasslands
Low insolation and below
freezing most of the year.
Few small plants and
grasses hug the ground.
Drought resistant small
trees and shrubs survive
hot, dry summers. They
are found on Western
coasts between 30° and
40° north and south.
High insolation heats moist air leading to high rainfall
and perfect growing conditions all year around.
Cool temperatures due to
weak insolation and moderate
rainfall as jet streams bring
regular storms.
High insolation, but sinking air
leads to hot and dry
conditions all year around.
Very little grows (e.g. Cacti).
Dry and rainy seasons mean grasses dominate
central continent areas between 40° and 60°.
Factors affecting global ecosystem distribution
• Altitude: Temperatures fall 0.5°C for every 100m increase so trees are replaced by grasses, then just rocks.
• Rain shadow: Rising air and moisture leads to rainfall on mountain ranges. Areas inland are starved of rain.
• Ocean currents: Cold currents create very dry weather due to little evaporation (Atacama Desert, Chile),
whereas warm currents create wet weather due to more evaporation (e.g. Gulf Stream – UK).

2. Key Areas Tropical Rainforests
Characteristics
of tropical
rainforests
Distribution of rainforests: In the tropics / north of South America / west Africa / SE Asian islands.
Rainforests contain dense vegetation and a very high biodiversity of plants and animals. This is due
to the perfect climate for growth (high rainfall and consistent warmth).
Rainforest
Cycles
Plant and
animal
adaptations
Plants & animals (biotic factors) have adapted to temperature, rainfall & soils (abiotic factors).
Biotic /
Abiotic Inter–
dependence /
relationships
1. Deforestation can mean that rainwater hits the ground with greater force leading to soil erosion and
poorer quality soil for other plants, which die. This means animals lose their habitat.
2. Fig Tree Wasps have a symbiotic relationship with the Fig Tree. They lay their eggs in the fruit which
keeps the young safe. As the wasp forces its way into the fruit it fertilises the tree.
3. Other trees also rely on insects and birds to scatter the seeds of their fruit.
Structure of a Rainforest Tropical Rainforest Climate Rainforest Soils
Rainforest soils have a thin,
layer of nutrients as rainwater
leaches (drains away) nutrients
leaving an infertile red, iron
rich soil called latosol.
High levels of rainfall, generally
over 200mm of rainfall.
Depending on location there are
normally peak ‘rainy’ seasons
(e.g. May). The temperature is
consistently high all year round.
Rainforest water cycle: Convectional Rainfall The nutrient cycle is rapid
and ensures that nutrients
are rapidly replaced in the
soil to support the dense
vegetation.
The dense vegetation
absorbs the soil nutrients
rapidly.
Fungi that grows on trees
takes nutrients from the
air.
Drip tips:
Allow water to
run quickly off
leaves to stop
them from
rotting.
Carnivorous plants: Plants such as Venus Fly Traps catch and
dissolve insects instead of producing food using photosynthesis as
there isn’t enough sunlight on the forest floor.
Jaguars: Sharp claws for climbing and long tail
for excellent balance in trees. They are strong
swimmers so flooding isn’t a problem.
Their large paws kill
prey quickly before it
can escape.
Lianas: They climb
trees to reach the
canopy and
sunlight for
photosynthesis.
Strangler Figs also
crush the tree it
climbs and takes its
nutrients.
Epiphytes: Grow up in the canopy on
tree branches to get sunlight for
photosynthesis & tree nutrients.
Leafcutter ants: They cut
leaves, bury them at the
base of trees where they
decompose. Fungi feeds on
the decomposing leaves
providing food for the ants.
They also link together to
create a raft protecting the
Queen and eggs from floods.

3. Value /
importance
of tropical
rainforests
Causes of
deforestation
in the
Amazon
Impacts of
deforestation
in the
Amazon
Cattle Ranching: The biggest cause of
deforestation as the forest is cleared
to make space for pasture for huge
cattle farms. The quality of pasture
quickly declines and so farmers move
on to destroy new areas. Brazil is now
the biggest producer of beef in the
world.
Small clearance is sustainable as once the tribes move on the forest can grow
back. However fires can grow out of control destroying large areas.
Other - Mining: Opencast gold mines
such as Grota Rica lead to mass
deforestation and a huge eyesore.
Commercial (large scale) agriculture:
Huge areas of the Amazon have been
felled to clear space for fields of
soybeans.
Logging: Timber such as mahogany
and teak is felled to use for furniture.
Other trees are used for building
materials and fire wood.
Major routes such as the
Transamazonica Highway
lead to more clearance as
large commercial logging
and agriculture companies
use them to transport
resources from the Amazon.
Small scale agriculture:
Subsistence farming by
tribes means areas of forest
are ‘slashed and burnt’ so
they can grow crops.
Other - Road construction: Strips
of forest are cleared to build roads.
Important Intact
The Amazon Rainforest
produces 1/5 of the
world’s oxygen.
The Amazon absorbs
600 million tonnes of
CO2 per year, the same
amount produced by
the European Union.
This will help to reduce
global warming as CO2
is a greenhouse gas
and traps heat in the
atmosphere.
Medical breakthroughs
leading to cures for
things such as cancer
are thought to be
found in rainforests.
Important Destroyed
Huge amounts of
money can be made
by destroying the
rainforest for
resources such as
wood and clearing
land for activities such
as cattle ranching and
crop production such
as soy, fruit and nuts.
But this money is not
sustainable as forest
is destroyed and land
loses fertility.
Resources under
rainforests such as oil
and gold can also
make lots of money.
Ecotourism can bring a
sustainable income to
rainforest areas as
tourists come to see rare
plants and animals in a
special environment.
Rainforests are
important, biodiverse
environments
providing food for
animals and tribes.
Gold mines such as Grota Rica create
huge holes of deforested rainforest,
destroying biodiverse habitat. The
generators powering the hoses used
to mine create noise pollution. This
scares away animals leaving less for
tribes to hunt. Muddy water from
the mine runs into rivers with the silt
clogging up fish gills, killing them.
Mercury used to separate gold from
the ground also leads to poisoning in
nearby rivers. This further reduces
food for tribes.
However, they do create jobs paying
workers more than they would get
paid in factories.
Deforestation means that less
oxygen is produced and less
carbon dioxide is absorbed.
With more CO2 in the air, more
heat will be trapped worsening
global warming.
When tree roots are removed
soil is eroded away by rainwater.
This removes the fertile, top
layer of soil and means nothing
can grow back. This also leads to
poor, unproductive farmland.
Deforestation
leads to the loss
of a biodiverse
habitat. It is
thought that 137
plant, animal and
insect species are
lost every day
due to rainforest
deforestation.
Loss of trees means more water sinks into the
ground, reducing the amount of evapotranspiration.
This reduces the amount of convectional rainfall
making rainforests drier. This can kill nearby areas of
forest and reduce the productivity of farmland.

4. Sustainable
management
of The
Amazon
Key Areas Cold Environments
Cold
Environment
Characteristics
Distribution: Polar and tundra areas are located around the poles
in the far north of North America, Northern Asia and Antarctica.
There are small Alpine areas found in location including the west
coast of South America.
International Schemes Local Schemes
REDD: HICs and international companies pay
countries like Brazil to protect rainforests like the
Amazon. Rainforests are carbon sinks (store CO2 ) so
the HICs/companies receive carbon
credits in exchange.
This enables them to pollute more
CO2 into the atmosphere without
being fined for their carbon footprint.
Debt reductions: Countries such as Brazil have their
debt s reduced if they protect their rainforests.
Government schemes: These can include:
• Creating nature reserves to protect
• Being tough on illegal logging
• Educating the importance of rainforests in schools.
In Brazil, IBAMA are the agency aiming to stop illegal
logging.
However, they only have 15 officers covering an
area the size of Wales. This, plus government
corruption means that few are caught and punished.
Replanted trees are often quick growing softwoods
rather than natural/native tree species.
Ecotourism: Juma Lodge, Amazon. Money is made
from tourists who visit rainforests and learn about
the importance of protecting them. They stay in
eco-friendly lodges that are made from local
materials that blend into the environment.
Activities include ziplining, kayaking and nature
walks, activities that don’t pollute the environment
and affect the biodiversity.
Selective logging/replanting: Only cutting down
selected (old) trees rather than the entire forest.
This means young trees can continue to grow and
the forest is maintained.
However, the old trees are important habitats for
many plants and animals and other trees can be
accidentally felled as the selected logs are cleared.
Freezing cold Winters and mild Summers. Low
precipitation, particularly during the Winter.
Polar Environment Characteristics Tundra Environment Characteristics
• Large temperature range (-40°C to 18°C).
• Low precipitation (snow): 100-200mm per year. Can be
higher in coastal areas.
• Brief summers with a short 6-10 week growing season.
• Soils are frozen permafrost but in the summer soil close to
the surface melts allowing plants to grow. This is called
the active layer.
• Large temperature range (-50°C to 10°C).
• Very low precipitation (snow): <100mm
per year.
• Permanent ice coverage.
• Little to no vegetation.
• Animals include Polar Bears in the
Arctic/Penguins in the Antarctic.
• Low lying plants that
hug the ground.
• Animals include
Arctic Foxes, Arctic
Hares and birds such
as Ptarmigans.

5. Plant and
animal
adaptations
Plants & animals (biotic factors) have adapted to temperature, precipitation & soils (abiotic factors).
Biotic /
Abiotic Inter–
dependence
1. Tundra plants are adapted to help them overcome environment challenges (See above)
2. This low lying vegetation in turn helps to protect the soil from wind erosion.
3. The soil is required to allow the plants to grow.
Opportunities
for
development
in Alaska
Challenges
for
development
in Alaska and
local scale
management
Bearberry
Very low growing to enable it to survive the strong
winds
Thick bark for stability in windy conditions
Small leathery leaves help
retain water n this dry
environment
Hairy stems help retain heat
and keep the plant safe from
very low temperatures
Bright red berries are eaten by birds and this helps
distribute the seeds
White fur: means it
cannot easily be seen
by predators in the
white snow
Two layers of fur: help them survive
extreme low temperatures.
Hooves: help them
travel over soggy land
and break through ice
to find drinking water
Shallow root system: roots only grow the active layer
of soil as they cannot penetrate the permafrost
Commercial fishing
takes place in the
Arctic Ocean. It
provides 78,500
jobs in Alaska and
contributes $5.8
billion to the
Alaskan economy
every year.Salmon is the most valuable
commercial fishery.
Tourism is one
of the activities
that has
resulted in
Alaska’s
economic
growth. 1.9
million tourist
visit each year
to see the
wildlife and
unique
scenery.
One in every 13 jobs in
Alaska is related to
tourism and it contributes
$4 billion to the economy
every year.
In the late 1800s
Alaska was
known as the
‘Gold rush state’.
One fifth of the
states mining
wealth comes
from gold.
Alaska has a wealth of
mineral resources including
gold, copper, iron ore and
lead.
Snowshoe Rabbit
Caribou
The glacial U shaped valleys
are ideal for HEP (there are 50
HEP power stations in the
state). As Alaska is tectonically
active, geothermal energy is
also used. Chena Hot Springs
is powered entirely by
geothermal.
The North Slope
of Alaska has
significant oil
reserves, mostly
discovered in the
Prudhoe Bay
oilfield. The oil
and gas industry
in Alaska is
responsible for
one third all jobs
and 90% of all
revenue (money
made) in Alaska.
Challenge How it can be overcome (local scale management)
Temperatures are extremely low (as
low as -60°C in the North).
Wearing warm clothing. Advancements in synthetic fabrics now mean that
not all warm clothing is bulky and difficult to manoeuvre in.
The heat that buildings and settlement
create can cause increased melting of
the soils permafrost. This can cause the
ground to subside (sink) which can
result in the buildings above also
subsiding.
Roads are built on deep gravel pads and buildings are now built on raised
piles to prevent melting, that are sunk deep well below the active layer to
reduce the transfer of heat from the building to the ground.
Utilities such as gas and sewage pipes cannot be buried
underground as they would freeze and/or melt permafrost.
Instead they are built in above ground corridors called
‘utilidors.’
Snow and ice can make roads unusable
for large parts of the year.
Many local communities use snow mobiles to get around.

6. Challenges of
oil extraction
in Alaska
The following challenges had to be overcome in order to build the pipeline
successfully.
• The ground in Alaska is frozen (permafrost), it needs to remain frozen to preserve the delicate
ecosystem.
• The temperature range in Alaska can be from -60°C and 35°C. Metals expand and contract with
changes in the temperature so the pipeline needs to be designed to accommodate these
changes.
• Alaska has regular, often large, earthquakes (the USA’s largest earthquake a 9.2 occurred
here). The pipeline needs to be designed not to break during these earthquakes.
• If the pipeline was to break or leak it would be a disaster for the surrounding fragile ecosystem.
• The pipeline would need to cross several caribou migration routes.
Managing oil
extraction in
Alaska
Balancing
development
and
conservation
in the Arctic
Global technology companies are relocating to cold environments.
Facebook and Google have relocated their data centres to Northern Scandinavia, Facebook is now in
Luleå, Finland.
Facebook users upload 150 million photos each day and all this information must be stored and
backed up. This involves huge energy costs to power and cool the computers.
These data centres are relocating to cold environments because:
• A cold climate – Luleå has long winters well below freezing
meaning that air conditioning and fans are not needed to cool
computers, lowering energy costs.
• Low energy costs – Luleå lies near a HEP power plant
• Flat land – Luleå is built on flat, glacially eroded land.
There are extensive oilfields in the north of Alaska, in Prudhoe Bay. The
sea is frozen here so can be exported using oil tankers. The Trans-Alaskan
Pipeline transports oil from Prudhoe Bay to Valdez where the sea is never
frozen
The temperature range in
Alaska can be from -60°C
and 35°C. Metals expand
and contract with changes
in the temperature so the
pipeline is insulated to
ensure more consistent
temperatures.
The pipeline has been built as a zig-zag.
This reduces the likelihood of breakages
during earthquakes or significant
temperature changes.
Large areas of the
pipeline are constructed
on stilts. The stilts allow
the pipe to move
sideways during
earthquakes and
avalanches. The stilts also
allow animals to migrate
beneath to find food and
shelter and stop the
warm pipes from melting
the fragile permafrost.
Small sections of the
pipeline are constructed
underground to pass
under roads, avoid
avalanches and major
caribou migration routes.
Underground sections
have refrigeration units
to ensure that the
permafrost remains
frozen.
Drilling for oil is restricted in some regions including offshore areas around Barrow and Bristol Bay.
The sea around Barrow is home to bowhead whales, and the Inapiat locals don’t want them to be
disturbed as they are a big part of their diets. Bristol Bay has many sockeye salmon fisheries that
need protecting.

7. Large scale
management
of cold
environments
in
Alaska/Arctic
International Schemes National Governments
The Arctic Council
This represents 8 countries and the
indigenous people of the Arctic. This was
created to encourage sustainable
development and to ensure that the needs
of the indigenous people were still able to
be met. One of its main focuses is to
reduce emissions that lead to increased
melting of Arctic ice.
International Whaling Convention
Introduced in 1986 due to Whales being
heavily hunted, effecting their numbers.
This convention banned whale hunting
(which was later changed to just
commercial whaling so the indigenous
population could still continue their
traditional way of life). Since this was
introduced the
number of
Bowhead Whales
has significantly
grown.
National governments are responsible for managing their
own ecosystems. In Alaska some areas have been given
protect as National Parks. Just over 10% of Alaska now has
some level of special protection. When in office US
President Barack Obama banned oil exploration in 12 million
acres of the Arctic National Wildlife Refuge (ANWR)
Non-governmental organisations (NGOs)
NGOs support the interests of groups that may not
otherwise be heard.
Inuit Circumpolar Council (ICC)
This represents indigenous people from
Nunavut and other regions. They campaigned
again a gold mine ‘Pebble mine’ which resulted
in one of the worlds biggest mining companies refusing to
mine there.
Greenpeace
This NGO has called for a ‘global sanctuary’ to be
established in the Arctic. This would mean banning all oil
drilling and industrial fishing. However this would restrict
the indigenous populations freedom to use their resources.