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

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

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

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

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

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

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

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

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

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

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

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

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