The Earth's Four Spheres
What are the four spheres of the Earth called?
Atmosphere, Biosphere, Hydrosphere, Lithosphere
What does “biodiversity” mean?
The variety of living things in an environment.
Name one natural event that changes the biosphere.
Flood, drought, bushfire, earthquake.
What is climate change?
A long-term change in the Earth’s temperature and weather patterns.
How has climate change affected the Great Barrier Reef?
Coral bleaching caused by warmer sea temperatures.
Which sphere contains all living things?
Biosphere
Do tropical rainforests have high or low biodiversity? Why?
High, because of warm, wet conditions all year.
Name one human activity that changes the biosphere.
Deforestation, farming, mining, urbanisation.
How does land clearing for farming affect the biosphere?
Removes vegetation, reduces habitats, increases soil erosion.
What is one sustainable way humans can use land?
Crop rotation, conservation farming, national parks.
The water cycle mainly occurs in which sphere?
Hyrdosphere
Why do deserts have less biodiversity than rainforests?
Lack of rainfall and extreme heat make survival difficult.
How does deforestation affect biodiversity?
Destroys habitats and reduces species numbers.
What are invasive species, and why are they a problem in Australia?
Non-native plants or animals that harm ecosystems (e.g. cane toads, rabbits).
Why are coastal ecosystems like mangroves important?
They protect shorelines, filter water, and support marine life.
When a volcano erupts, which two spheres are directly interacting?
Lithosphere and Atmosphere
This country is near the equator, hot and wet with thick forests — what type of biodiversity does it have?
Tropical biodiversity – many plants and animals.
The 2019–2020 Australian bushfires destroyed millions of hectares of forest. Which spheres were affected?
Biosphere, Lithosphere, Hydrosphere, Atmosphere.
How does pollution affect ocean ecosystems?
Plastics and chemicals harm marine life and coral reefs.
What happens when invasive species outcompete native species?
The native species can decline or become extinct.
A drought affects plants and animals. Which spheres are involved and how?
Hydrosphere (less water), Biosphere (living things suffer)
Why is northern Australia more biodiverse than central Australia?
Northern areas are wetter and warmer; central areas are dry desert.
How can land use for farming or cities lead to soil degradation and loss of biodiversity?
Clearing land removes vegetation and tree roots, leading to erosion, poor soil health, and loss of habitats for plants and animals.
Explain how rising global temperatures affect biodiversity.
Warmer climates change habitats — species may migrate, die out, or lose food sources.
How can individuals reduce their impact on the biosphere?
Recycling, planting trees, using less energy, reducing waste.