Ecosystem Earth
Most natural ecosystems are constantly changing. The types and abundance of organisms in the ecosystem change because the abiotic and biotic factors change. For example, changed weather conditions, such as heavy rain or prolonged dry weather, change the availability of food or the presence of disease-causing organisms. However these changes are rarely permanent, and the ecosystem usually recovers over a period of time.
Human activity, on the other hand, can dramatically change the type and composition of an ecosystem. In many cases, the activity can change the ecosystem permanently. For example, much of the lowland coastal forests along the Queensland coast have been cleared for agriculture, particularly sugar cane. Humans can change both the biotic and abiotic factors in an ecosystem. They can alter the food source through the clearing of vegetation and introduce predators such as cats and dogs to food webs. Clearing also alters soil fertility, and household and industrial wastes can change the quality of the air and water.
Can humans balance their activities and needs as well as conserving, protecting and maintaining the quality of the environment?
Aspects Covered
- Living in Ecosystems
- Survival in Ecosystems
- The Earth as an Ecosystem
Resources
Student Outcomes
| Student Outcomes | Text References | Elements of SACSA Framework |
|---|---|---|
| Examples of evidence include that the student: | ||
| gathers information to identify and describe the factors that led to disturbance of a local ecological system, and explores alternatives for the future | p 276 (Act) | Life Systems 3.5 and Futures (F) |
| interrogates and debates issues associated with species diversity, including contemporary rates of species loss and human use of natural environments | p 277-280 | Life Systems 4.6 and Interdependence (In) |
| explains why there is a limit to the number of links in food chains within an ecosystem | p 272-273 | Life Systems 5.5 |
| identifies the biotic and abiotic factors that influence the survival of organisms | p 275 | |
| explains how a great diversity of species increases the chance that at least some organisms will survive large-scale changes in the environment | p 277-278 | |
| discusses how changes in biodiversity can be affected by conservation or preservation, introduced species and human influence | p 277-278 | |
| compares and contrasts natural and urban ecosystems | p 279 | |
| uses a case study of the Gippsland Lakes to illustrate the impact of human activities | p 280 | |
| charts the transfer and transformation of material and energy through a food web | p 271-274 | Life Systems 5.6 |
| interprets evidence and examines causes of the depletion of the ozone layer, using a range of resources | p 287-288 | Earth and Space 4.1 |
| recalls the names and characteristics of the three main layers of the Earth's atmosphere | p 282 | |
| evaluates the potential impact of global warming and ozone depletion | p 282-288 | |
| explains the greenhouse effect in terms of the transmission and reflection of heat energy | p 283 | |
| describes the major effects of ozone depletion | p 287 | |
| demonstrates understanding of the reactions that occur in the ozone layer | p 287 | |
| uses graphs to illustrate and compare various global warming scenarios | p 286 Wbk p 100 | KC5 Using Maths |
| writes a problem-solution essay about the hole in the ozone layer | Wbk p 99 | KC2 Communicating Ideas and Communication (C) |
Assessment
| Summative Assessment | |
|---|---|
| Assessment Type | Weight |
| Skills Worksheet | 2.5% |
| Practical Skills Lab Skills | 2.5% |
| Test | 5% |
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CRICOS Name: Department of Education and Children's Services T/A South Australian Government Schools | CRICOS Number: 00018A