Human Influence

in Ecosystems

Humans impact upon ecosystems in a multitude of ways – many of which are irreversible, most of which

are controversial.

Humans impose their lifestyles upon the environment with varying degrees of respect. Regardless of the impact, the

environment is forced to respond.

The abiotic environment has very little defence against the devastating conditions humans can create. If it is continually

imposed upon it will begin to break down and will not be able to support biotic elements. If left alone, over time it may regain its ability to support life. When a natural environment reclaims its

territory, it is known as succession.

The biotic environment also has minimal defence but can respond to human impact in one of 3 ways: change

location, adapt, or become extinct.

Change location: plants can spread their seeds further a field in order to escape the unfavourable conditions of their physical environment. If possible, animals can move to another habitat that is favourable for

survival.Adapt: organisms can do this either physically, behaviourally or

physiologically. Most organisms require slow changes in the environment (like the evolutionary changes linked to the changing climate caused by the movement of the continents) to be able to adapt physically or physiologically. The types of changes humans cause are usually too rapid for the organism to adapt to the new

environment. Animals might be fortunate to adapt their behaviour to make living in a changed environment favourable.

Extinction: If an organism is unable to change location or adapt to the changes humans have created, then it will not be able to

survive and will die out or become extinct.

•Use the following slides to discuss with your class the impact humans have had in the various ecosystems. Some points to cover…

•Talk about the effects and responses of the abiotic and biotic elements.

•Look for examples of adaptations of living things in response to the human impact.

•See if you can find evidence of succession.

•Make suggestions for a better future.

•Debate the ‘necessity’ of the various forms of human activity.

•Imagine positive ways forward.

The End!