Summary
The Antarctic ecosystem is a unique and fragile environment characterized by extreme cold, minimal precipitation, and powerful winds, making it one of the harshest places for life on Earth. Despite these conditions, the surrounding Southern Ocean supports a rich marine ecosystem with complex food webs.
- Antarctica — the southernmost continent on Earth, located at the South Pole. Example: It is surrounded by the Southern Ocean and has no permanent human residents.
- Polar Desert — a region with extremely low precipitation, despite being covered in ice and snow. Example: Antarctica receives less than 50mm of precipitation annually.
- Abiotic Factors — non-living components of the environment affecting living organisms. Example: Extreme cold, wind, and limited sunlight in Antarctica.
- Biotic Factors — all living organisms within an ecosystem interacting with each other and their environment. Example: Penguins, seals, krill, and phytoplankton in the Antarctic ecosystem.
- Keystone Species — a species with a disproportionately large effect on its ecosystem. Example: Krill, which are crucial for the Antarctic food web.
Exam Tips
Key Definitions to Remember
- Ecosystem
- Abiotic Factors
- Biotic Factors
- Food Web
- Keystone Species
- Adaptation
Common Confusions
- Confusing the direction of energy flow in the food web
- Forgetting the role of krill as a keystone species
Typical Exam Questions
- Why is Antarctica classified as a polar desert? Answer: It receives less than 50mm of precipitation annually, making it drier than the Sahara Desert.
- What would happen to the Antarctic food web if krill populations suddenly declined by 50%? Answer: All species that feed on krill would face starvation, causing ecosystem collapse.
- Explain how the angle of the sun affects Antarctica's temperature. Answer: Sunlight hits Antarctica at a low angle, spreading energy over a larger area, delivering less heat per square meter than at the equator.
What Examiners Usually Test
- Understanding of why Antarctica is so cold
- Ability to link abiotic factors to their effects on organisms
- Knowledge of the Antarctic food web and the role of krill
- Examples of adaptations in Antarctic animals