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, CO 2 (carbon dioxide), O 2 (oxygen), matter, nutrients. Processes: Processes can be transpiration, growing, eating, absorption, respiration, photosynthesis, etc. Outputs: Outputs are waste or unwanted products such as O 2 (oxygen), water, dead matter, CO 2 (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?