Introduction to Ecosystems

What is a SYSTEM?

• A system is a set of parts which link together to make the system work.

• There are inputs and outputs to the system.

• A car's engine is an example of a system. An input to a car is petrol and an output is exhaust gases.

What is an ECOSYSTEM?

• An ecosystem is a group of living things plus the non-living things they need.

• The parts of an ecosystem are linked together.

• For example: in a woodland ecosystem, rain is an input which makes the trees grow. Evaporation is an output.

• Copy the diagram and add examples to each box.

Examples of inputs/outputs/processes

• Inputs:The inputs into an ecosystem may be water, CO2 (carbon dioxide), O2 (oxygen), matter, nutrients.

• Processes:Processes can be transpiration, growing, eating, absorption, respiration, photosynthesis, etc.

• Outputs:

Outputs are waste or unwanted products such as O2 (oxygen), water, dead matter, CO2 (carbon dioxide).

At what SCALE do ecosystems operate?

• There are many different ecosystems in the world.

• Some are small-scale, such as a pond.

• Others are large-scale and cover vast areas, such as a rainforest.

STORES and FLOWS

• An ecosystem has a series of stores and flows.

• In the woodland ecosystem, energy and matter is stored in the wood and the leaves.

• There is a flow of nutrients from the soil to the leaves.

• These are part of cycles such as the nutrient cycle and the water cycle.

FOOD CHAINS

• Living things in the ecosystem are linked together by the flows of energy and matter as things eat each other.

• These links can be shown as food chains

FOOD CHAINS

This shows a food chain in the sea. Removing one animal from this would seriously harm the system.

HOW?

FOOD WEBS

This shows a food web in a woodland area.

What would happen if the RABBITS were removed from the ecosystem?