1. Natural Sciences and Technology Grade 6
Term 1: Life and Living
Ecosystems and Food Webs

2. Topic 5 Ecosystems and Food Webs
Ecosystems – Part 2
Gr 6 Natural Sciences and Technology – Term 1, Topic 5

3. Living and Non-living things in an Ecosystem
A rocky shore is an example of an ecosystem.
It includes both
non-living and
living things.
Gr 6 Natural Sciences and Technology – Term 1, Topic 5

4. Living and Non-living things in an Ecosystem
The non-living part of a rocky shore ecosystem includes
water,
rocks,
sunlight,
air,
sand and soil.
Gr 6 Natural Sciences and Technology – Term 1, Topic 5

5. Living and Non-living things in an Ecosystem
The living part of a rocky shore ecosystem includes
Barnacles,
Algae,
Seaweeds,
Mussels,
Crabs,
Penguins and
Seagulls.
Gr 6 Natural Sciences and Technology – Term 1, Topic 5

6. Living and Non-living things in an Ecosystem
In an ecosystem, living things can be grouped into:
Plants
Animals / people
Micro-organisms
Gr 6 Natural Sciences and Technology – Term 1, Topic 5

7. Micro-organisms in an Ecosystem
Micro-organisms are organisms that:
can only be seen through a microscope;
consist of only a single cell;
are the most important part of any ecosystem.
Examples include: certain fungi and algae, bacteria and protozoans.
Gr 6 Natural Sciences and Technology – Term 1, Topic 5

8. Interdependence
Relationships between plants and animals as well as other things (non-living materials, air, water, etc.) in their habitat are important for their survival. We call this interdependence.
Gr 6 Natural Sciences and Technology – Term 1, Topic 5

9. Biodiversity
Biodiversity, refers to the different species of plants and animals in a given ecosystem.
Gr 6 Natural Sciences and Technology – Term 1, Topic 5

10. The importance of water in an ecosystem
Animals depend on water in their ecosystems.
Water provides a habitat for different plants and animals.
Water is important for photosynthesis.
Water plays a role in plant production – some seeds are dispersed by water.
Gr 6 Natural Sciences and Technology – Term 1, Topic 5

11. Balance in ecosystems
An ecosystem depends on the right balance of plants, animals and elements to stay healthy.
The introduction or removal/destruction of certain elements can result in an unhealthy ecosystem.
In unhealthy ecosystems the animals and plants start to die.
Gr 6 Natural Sciences and Technology – Term 1, Topic 5

12. Threats to ecosystems Type Threats Rivers Mountains Seas Wetlands
Water pollution, drought, green algae, etc.
Mountains
Soil erosion, locust invasions, fires, etc.
Seas
Water pollution, red tide, poaching, etc.
Wetlands
Drought, pollution, extinction of birds, etc.
Ponds
Drought, weeds, etc.
Rocky shores
Theft of sea shells, rubbish, etc.
Gr 6 Natural Sciences and Technology – Term 1, Topic 5

13. Threats to ecosystems Type Threats Grasslands Forests
Fires, poaching, over-grazing, land use for farming, etc.
Forests
Fires, poaching, chopping down trees for timber, clear forest for road building, etc.
Deserts and semi-deserts
Droughts, poaching, land use for housing, etc.
Arctic and alpine tundra
Global warming, land encroachment, etc.
Fynbos
Acid rain, fires, land encroachment, etc.
Gr 6 Natural Sciences and Technology – Term 1, Topic 5