The Biosphere Sub topic (a) Investigating an Ecosystem NameTeacher.
The Biosphere Sub topic (c) Control and Management Name Teacher.
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Transcript of The Biosphere Sub topic (c) Control and Management Name Teacher.
The Biosphere
Sub topic (c)
Control and Management
Name
Teacher
Pollution• Pollution happens
when substances contaminate (harm) the environment.
• Pollution affects air, fresh water, sea and land – our air is no longer pure, our seas are a dumping ground and our land contains lots of man made waste
Sources of pollution• The main sources of
pollution are domestic, agricultural and industrial.
• Domestic – sewage and rubbish e.g. plastic
• Agricultural – fertilisers and pesticides
• Industrial – smoke and gases from factories and power stations
Energy Sources and pollution (C)• Lots of our energy is
generated by• burning fossil fuels such as
coal , oil and gas. These fuels are non renewable and supplies will run out
• Burning releases harmful gases into the air e.g.
• Sulphur dioxide – causes acid rain
• Carbon monoxide – which is poisonous
• Carbon dioxide – leads to global warming
Energy Sources and pollution (C)• Some of our energy is
generated by nuclear power stations.
• This leads to the formation of nuclear waste which is very dangerous -
• It can enter food chains• Can cause cancers• Has to be stored safely for
hundreds of years
Controlling pollution• Pollution can be
controlled by • Reducing the burning
of fossil fuels and using alternative energy sources e.g. wind
• Removing harmful gases from factory chimneys using special equipment before release into the air (SCRUBBING)
Organic waste Pollution• Organic waste e.g.
sewage is a food source for micro organisms.
• If organic waste increases in a river/sea then it means an increase in micro organisms which rapidly use up the oxygen in the water
• leading to less oxygen in the water for other organisms e.g. fish
Testing River Water for Bacteria
Methylene blue is a blue dye that shows us how much oxygen is in a sample of water.
The blue dye loses its colour and becomes colourless as oxygen is used up.
If your water sample is polluted by lots of dangerous bacteria, the oxygen will be used up and the blue colour will disappear
Dye added
Dye added
Loses colour
Still blue
Blue gone
Oxygen low
Pollution high
Blue
Oxygen high
Pollution low
Water sample
Water sample
Now its Your Turn
Ouch!
goggles
samples of polluted and unpolluted water
methylene blue
2 screw top bottles
oil + dropper
Wear goggles for this experiment
Collect;
And gloves
What To Do
1. Label your bottles
2. Add a different sample to each bottle
3. Add methylene blue
4. Mix gently then add a few drops of oil to form a layer on the surface
3. Examine at end of period
4. Examine again next day
polluted
unpolluted polluted
oil
Clean river
More food for micro organisms
Number of micro organisms increases
Micro organisms use up lots of oxygen
Low level of oxygen in water
Number of species present is reduced as most organisms die due to a lack of oxygen
Organic pollution enters water Effect of Pollution (c)
Indicator Species (C)• Some fresh water
invertebrate animals are very sensitive to the level of oxygen in water.
• If oxygen is used up by large numbers of micro organisms feeding on pollution these organisms will die.
• Organisms that can give information on pollution /environment are called indicator species
Stonefly nymphs are only found in unpolluted water
Caddis fly larvae can survive in slightly polluted water
Indicator Species (C)
• Some species can tolerate low levels of oxygen and can indicate polluted water
• if there are no species such as stonefly nymphs or caddis fly larvae present in the water then there is little oxygen and the water is polluted.
Blood worms can be found in polluted water
Rat tailed maggots can survive in heavily polluted water
Lichens as Indicator Species (C)• Shrubby lichens can
only live in unpolluted air• Leafy and crusty lichens
can tolerate some sulphur dioxide in the air
Crusty lichens
Shrubby lichens
Leafy lichens
Management of natural resources
Pollution is an example of bad management, others are;
Natural resource
Poor management
Problem caused
Improvements
fish stocks
overfishingreduced numbers of fish
introducing fish quotas
rainforestdestruction to provide crops
1. soil erosion2. loss of soil fertility3. loss of plant species
increase the productivity of existing farmland
Agricultural Management (C)
_____________ was used in the past
This ; 1. __________________________
2. ____________________________
Crop Rotation
prevents build up of disease
allows nutrient levels to recover
Today farmers produce higher yields by using _________ to control pests and disease, and to return nutrients to the soil before planting e.g.
soil fertility ---- _________ replace phosphates and
nitrates removed by harvesting plants.
chemicals
fertilisers
Different plants have _______ nutrient requirements.
Long rooted plants remove nutrients from _______ soil than short rooted plants, so planting a ________ crop each year for four years allows the same land to be used ____________ before ________.
different
deeperdifferent
several timesdepletion
Year 1
wheat
Year 2 Year 3 Year 4
turnips barley clover
Crop rotation
Clover – a leguminous plant
root nodules
Clover is not harvested. It is a leguminous plant --- it has root nodules containing bacteria which ____atmospheric nitrogen, converting it into_______. When the clover is ploughed into the ground it______________________.
‘fix’nitratereplenishes soil nitrate
Disease / pest control ----- 3 types of pesticide are sprayed onto crops ;
1. ____________________________________
2. ____________________________________
3. ____________________________________
insecticides – to kill insect pests
fungicides – to kill fungus
herbicides – to kill weeds
R.I.P
Agricultural Management (C)
Quick Test 1
1. What is pollution?
2. Name 4 ecosystems affected by pollution.
3. Name the three sources of pollution.
4. Give an example of domestic pollution.
5. Give an example of agricultural pollution.
6. Give an example of industrial pollution.
When substances harm the environment
Air, fresh water, sea, land
Domestic agricultural industrial
Sewage , rubbish
Fertilisers, pesticides
Smoke, gases fromfactories
Quick Test 21. Name two ways of generating electricity?
2. Name two harmful gases released by burning fossil fuels.
3. What are the dangers of nuclear waste?
4. Give two ways of controlling pollution.
5. Give an example of organic pollution.
6. Describe what happens when organic pollution enters a river.
Burning fossil fuels/ nuclear power
Can enter food chains, cause cancers, stored for hundreds of years
Reducing fossil fuels/ alternative energy sources, removing harmful gases
Sewage
Increase in microbes use up lots of oxygen
Low level of oxygen fish die due to lack of oxygen
Sulphur dioxide. Carbon monoxide, carbon dioxide
Quick Test 31. What is an indicator species?
2. Name two invertebrates that can only be found in unpolluted water.
3. Name two invertebrates that can be found in polluted water?
4. Why is there a lack of oxygen in polluted water.
5. Why are lichens pollution indicator species?
Organisms that give information on pollution/ environment
Blood worms. Rat tailed maggot
Large numbers of micobes use up the oxygen
Lichens cannot live in polluted air/ high levels of sulphur dioxide
Stonefly nymph, caddis fly larvae
Quick Test 41. Give two examples of bad management of
natural resources?
2. What problem does overfishing cause?
3. How can overfishing be controlled?
4. Why does agricultural land lose minerals / fertility?
5. How does a farmer increase soil minerals.
6. How does a farmer control weeds and animal pests
Over fishing /destruction of rainforest / pollution
Reduced numbers of fish species
Crop removed so no recycling
Introduce fish quotas
Adds fertiliser / manure/ crop rotation
Sprays herbicides (weedkiller) / pesticides