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TOPIC 1 Lesson 3. Ecosystems at a variety of scales. Syllabus Link 1.1.2 - Apply the systems concept on a range of scales. . What do we mean by scales?. Global? Regional? National? Local?. Ecosystems at Different Scales. We will look at Ecosystems that are at 3 separate scales:
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TOPIC 1 Lesson 3 Ecosystems at a variety of scales. Syllabus Link 1.1.2 - Apply the systems concept on a range of scales.
What do we mean by scales? Global? Regional? National? Local?
Ecosystems at Different Scales We will look at Ecosystems that are at 3 separate scales: • GAIA – The “global” ecosystem. • BIOME – Large / national scale ecosystem. • POND – Local scale ecosystem.
Gaia Intro 1 http://www.youtube.com/watch?v=xVGuRX0xNaI • Gaia Intro2 http://www.youtube.com/watch?v=4tXfX4qpGjc up to 2:32
GAIA • 1979 – James Lovelock “the Earth is a planet-sized organism, and the atmosphere is its organ that regulates it and connects all its parts”. • He argued that the biosphere keeps the composition of the atmosphere within certain boundaries by negative feedback mechanisms. Interactive Simulation: http://library.thinkquest.org/C003763/flash/gaia1.htm Wider Reading: http://www.scienceclarified.com/Ex-Ga/Gaia-Hypothesis.html
His argument was based on: • Earth’s surface temperature remains constant, even though the sun is emitting 30% more energy than when the Earth was formed. • The composition of the atmosphere is constant (79% Nitrogen, 21% Oxygen, 0.03% CO2). Oxygen is a reactive gas but its proportion in the atmosphere doesn’t change. • Ocean salinity is constant at around 3.4%.
The Biosphere • Stretches from the bottom of the oceans to the lower layer of the atmosphere. Hydrosphere Biosphere Lithosphere Atmosphere
BIOME “A large naturally occurring community of flora and fauna occupying a major habitat” • Log on to www.worldbiomes.com as a starting point. • What are the major biomes around the world? • Create a mind-map that covers all the major types and sub-types, including examples and key characteristics.
LOCAL SCALE - POND http://www.thewaterpage.com/pond-ecosystem.htm Draw a system diagram for the pond here at KGV. You may wish to take photographs / make notes around the pond to bring back to help you.