50-minute lesson
Year 9 Geography: Biomes of the world
Lesson objective
- Define biome and identify the world's major terrestrial biomes.
- Explain how climate shapes the distribution of biomes.
- Describe how people have modified biomes for food production.
Success criteria:
- I can name and locate at least five major biomes.
- I can explain how temperature and rainfall influence biomes.
- I can give an example of a biome modified for agriculture and describe the consequences.
Materials
- A world biome map (atlas)
- Climate graphs for several cities
- Notebook
Introduction
5 minIntroduce today's words:
- biome: A large region with a distinctive climate, vegetation and animal life.
- savanna: A tropical grassland with scattered trees and distinct wet and dry seasons.
- tundra: A cold, treeless biome with permanently frozen subsoil (permafrost).
- anthrome: A biome significantly altered by human activity, such as farmland or cities.
- deforestation: The clearing of forests, usually for farming, logging or settlement.
Ask your child what they already know about biomes of the world.
Explanation
10 minA biome is a large region with a distinctive climate, plants and animals. Climate, especially temperature and rainfall, is the main factor that determines where biomes occur.
Major land biomes include:
- Tropical rainforest: hot and wet all year, extremely high biodiversity (e.g. the Amazon, Congo Basin, parts of Southeast Asia and far north Queensland).
- Savanna: tropical grassland with scattered trees and wet and dry seasons (e.g. much of northern Australia and East Africa).
- Desert: very low rainfall, plants adapted to dry conditions (e.g. the Sahara and much of inland Australia).
- Temperate forest and grassland: moderate rainfall and four seasons (e.g. south-eastern Australia, Europe, the North American prairies).
- Boreal forest (taiga) and tundra: cold climates of the far north, with conifer forests (taiga) and treeless tundra.
People have changed biomes on a massive scale, especially to grow food. Large areas of grassland and forest have been converted to cropland and pasture. Geographers sometimes call these human-shaped landscapes anthromes. Deforestation for agriculture can reduce biodiversity, cause erosion, alter water cycles and release carbon dioxide.
Worked examples
8 minIdentifying a biome from climate data
A place has average temperatures of 26–28 °C all year and rainfall over 2,000 mm a year spread across all months. Which biome is it?
Step 1: Hot all year: tropical.
Step 2: Very high rainfall in every month: wet all year.
Step 3: Tropical + wet all year = tropical rainforest.
Answer: Tropical rainforest.
Consequences of modification
Explain two consequences of clearing tropical rainforest for cattle grazing.
Step 1: Environmental: loss of habitat and biodiversity, and release of stored carbon.
Step 2: Soil: rainforest soils are often thin and lose fertility quickly once the forest is removed.
Answer: Biodiversity loss and carbon release; rapid soil degradation.
Guided practice (do together)
10 min1. What is the main factor determining where biomes occur?
(a) Population (b) Climate (c) Language (d) Roads
2. Which biome covers much of northern Australia?
(a) Tundra (b) Boreal forest (c) Savanna (d) Temperate rainforest
3. Which biome has the highest biodiversity?
(a) Tropical rainforest (b) Desert (c) Tundra (d) Boreal forest
4. What is an anthrome?
(a) A type of desert (b) An ocean current (c) A cold forest (d) A biome significantly altered by humans
Independent practice
12 min5. Which is a consequence of deforestation?
(a) Loss of habitat (b) More biodiversity (c) Less erosion (d) More stored carbon in trees
6. A cold, treeless biome with permafrost is called ____.
7. Another name for the boreal forest is the ____.
8. A tropical grassland with scattered trees is called a ____.
Questions to check understanding
- Can you name and locate at least five major biomes?
- Can you explain how temperature and rainfall influence biomes?
- Can you give an example of a biome modified for agriculture and describe the consequences?
- What was the trickiest part today?
Answer guide
1. Climate — Temperature and rainfall shape biomes.
2. Savanna — Northern Australia is largely tropical savanna.
3. Tropical rainforest — Tropical rainforests are the most biodiverse land biome.
4. A biome significantly altered by humans — Anthromes are human-shaped biomes such as farmland and cities.
5. Loss of habitat — Clearing forests destroys habitat.
6. tundra — Tundra is found in the Arctic and high mountains.
7. taiga — Taiga is the boreal coniferous forest.
8. savanna — Savannas have wet and dry seasons.
Review
5 minRecap the success criteria together. Watch for these common misconceptions:
- Many think deserts are always hot. Antarctica and the Gobi are cold deserts; deserts are defined by low precipitation.
- Biome boundaries on maps look sharp, but in reality biomes merge gradually.
Extension activities
- Create an annotated world biome map with climate graphs for one location in each.
- Investigate how one biome in Australia has been changed by agriculture.
- Research an Indigenous-led land management project in a biome outside Australia.
Suggested follow-up
- Revisit biomes of the world tomorrow with two or three quick questions from memory.
- Try the online practice check for this topic and look at any questions that need another go.
Tips for parents
- Compare climate graphs of two places your family has visited or has connections with.
- Watch a nature documentary and identify the biome shown.
- Discuss food labels: where in the world, and in which biome, was this grown?