What is air?
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Air is a mixture of gases
Nitrogen 78.09%, Oxygen 20.95%, 1% other

Why is it important?

Life on earth

Humans

Air pollution
Sources :
Vehicles Factories Houses Aerosols Farming
Effects:
Smog Acid rain Climate change

Nitrogen pollution
 Sources: Car fumes, factories, fertilisers
 Problem: Producing too much nitrogen
 Effects: Acid rain, harming ecosystems, contributing to global warming

Where do you find the most nitrogen pollution?
Countryside Suburban City

Bio-indicators
 Bio-indicators are living organisms that can be used to monitor the health of an environment or ecosystem.
Examples include:
 Canaries used by coal miners
 Invertebrates in streams e.g. Mayfly nymph

I have a flattened body
What is a lichen?
I have no roots
I have no stem
I have no leaves

Lichens – Two lives in one
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A lichen is a partnership between a fungus and an alga.
The fungus (mycobiont) provides protection and the alga (photobiont) provides food.
 Reproduce by fragmentation or through soredia

Symbiosis or controlled parasitism ?

By existing together they can live in places they couldn’t survive on their own.

Where do lichens grow?
• Anywhere – even in the most extreme environments
Hot
African deserts Rocky shores
Cold
Alpine peaks

Lichen biodiversity
• 18,000 identified worldwide 1,700 in Britain
Bushy Leafy Crusty
• Some lichens are more tolerant to pollution than others
I nitrogen!
I hate nitrogen!

Spot the lichen
1
2
3

Activity 1 – lichens on trees
 Sample 4 deciduous trees – un shaded
1
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Identify the tree species
Measure the girth of the tree
Identify all indicator lichens on one face of the trunk
Look at the twigs of the tree – record lichens
Record insects that you see
2 3 4

Tar spot
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Fungus Rhytisma acerinum
Sensitive to pollution
Growth is reduced by sulphur dioxide and oxides of nitrogen
The more tar spot the less polluted the air
Count as
2 spots

Make your results count
Website : www.OPALexplorenature.org
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