Ecosystems

What is an ecosystem?An ecosystem is a community of living organisms

(plants and animals) sharing an environment. The largest ecosystems are called biomes.

What is a biome? A biome is a very large ecosystem e.g. the tropical

rainforest.

DESCRIBE the distribution of world biomes.EXPLAIN their distribution.

Simplified map to show world biomes

B

BB

B

water

Inputs stores outputsAnimals migrating into

the area

Rock weathering

precipitation

Soil weathering

biomass

photosynthesis

carbon

transpiration

Animals migrating out

drainage

Inputs, stores and outputs of an ecosystem

The earth receives about one one-billionth of the sun’s energy output.

71% powers physical processes such asheating the soil, air, & water,

wind, ocean currents, evaporation, etc.

28% of which is reflected by atmosphere & sea surface,

1% is trapped by photosynthesis (available to life).

What happens to the sun’s energy?

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Energy Transfer & Loss

• Energy enters the ecosystem as visible light,

• Transfers to chemical potential, to kinetic, to heat,

• Loss from system as heat or infrared radiation.

Energy flow in an ecosystemThe sun is the source of all energy for all life on earth. The initial process in energy flow is that of photosynthesis where light energy from the sun is trapped by green plants and turned into chemical energy, which can then be used for plant growth. Energy is then passed along through the ecosystem as food in a food chain or in a more complex food web.

An ecosystem is also made up of different groups of producers and consumers and decomposers. From the plants providing food to the bacteria breaking down the DOM

Autotrophs: create their own food supply e.g. plants

detritivores

omnivores

How does energy move through an ecosystem?

Label the autotrophs (producers), herbivores, carnivores omnivores and decomposers in this food web.