Ecosystem Changes – Lesson Summary

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Learning Objective

In this lesson we will learn how ecosystems change due to natural events as well as human activity.

Learning Outcomes

By the end of this lesson you will be able to:

  • Describe predator-prey cycles.
  • Describe the ecological impacts of natural disasters such as drought and bushfires.
  • Describe the ecological impacts of human activities such as land clearing, agriculture, hunting and fishing, introduced species and pollution.
  • Discuss how certain species are adapted to cope with natural environmental changes, but not the accelerated rates of change due to human activities.

 
changes to ecosystems lesson contents

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Lesson Topics

1 | Changes to Ecosystems

2 | Predator-Prey Dynamics

3 | Droughts

4 | Bushfires

5 | Human Impacts on Ecosystems

6 | Land Clearing and Agriculture

7 | Hunting and Fishing

8 | Introduced Species

9 | Pollution and Climate Change

10 | Summary

Lesson Summary

  • As dynamic systems, ecosystems are constantly changing.
  • Changes to ecosystems can be the result of natural events or human activity.
  • Primary changes can induce a cascade of secondary changes.
  • The population sizes of predators and their prey are interrelated and follow a cyclical pattern know as a predator-prey curve.
  • Natural events, such droughts and bushfires, can have significant impacts on ecosystems.
  • Droughts reduce water availability in soil and waterways, leading to the death of plants and animals, loss of food sources and habitat, and soil erosion.
  • Bushfires impact ecosystems through the direct death of plants and animals, as well as the loss of food sources and habitat.
  • Many species have evolved to adapt to or even rely on these types of ecosystem changes.
  • Human activity has resulted in enormous impacts on natural ecosystems, through activities such as land clearing, agriculture, hunting and fishing, introduction of new species, and pollution.
  • The resulting loss of habitat and food sources, competition and predation has lead to countless extinctions worldwide and left many more critically endangered.
  • Today, climate change due to carbon emissions poses the biggest threat to biodiversity globally.

 
epicormic sprouting eucalyptus

(Image: CSIRO Science Image)

(Header image: pavlobaliukh, Adobe Stock)