Transcript Inputs, Processes and Outputs in Ecosystems

Ecosystems as a System
Aims
• To understand that ecosystems operate as a system.
• To learn what the inputs, processes and outputs of
ecosystems are.
Inputs, Processes and Outputs in Ecosystems
The ecosystem is our environment, our surroundings. In an
ecosystem, materials are exchanged from one part to other
parts e.g. vegetation needs water, carbon dioxide and
nutrients from parts of its ecosystem. In exchange, the
vegetation enriches the soil when it dies and decomposes.
An ecosystem may be very large, such as a tropical rainforest,
or very small, such as a single oak tree, but all ecosystems
have their own systems of exchange and their own special
environments.
All ecosystems have:
Inputs – Things entering it – eg sunlight, rainfall
Processes – Things operating within it – photosynthesis,
weathering of rock into soil, decomposition
Outputs – Things leaving it – the scenery/landscape,
evaporation
People can also damage and pollute the ecosystem through
their activities e.g.
• Oil spills at sea.
• Warm water from power stations being put back into rivers.
• Deforestation.
• Air pollution from factories.
Activity: An Oak Tree Ecosystem
TASK:
Label the inputs,
processes and
outputs then colour
code them using the
key below
KEY
Inputs
Processes
Outputs
The Balancing Act
Ecosystems are delicately balanced but they can change over
time. This may be because new plants arrive, the climate
changes or because of human activity.
In most of the populated areas of the world, the natural
vegetation has been cleared, often by fire.
When trees are cut down or grasses are ploughed up for
agriculture, the natural ecosystem is destroyed. The nutrients
that went into the soil from dead leaves or roots no longer
exist and have to be replaced by fertiliser or manure. The
protection given by continuous plant cover from wind and rain
no longer exists, so erosion becomes a problem. As plants are
cleared and animals are killed, food chains are disrupted.