Ecosystems: Hot Deserts — GCSE Geography Revision

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What is Ecosystems: Hot Deserts?

Hot deserts are arid environments that receive less than 250mm of rainfall per year. They are typically found in subtropical regions, roughly 30° north and south of the Equator, in areas of high atmospheric pressure. Temperatures are extreme, with very hot days and surprisingly cold nights. Plants (xerophytes) and animals have a range of adaptations to cope with the lack of water and extreme temperatures.

Board notes: AQA, Edexcel, and OCR all require the study of a hot desert ecosystem. Key themes include plant and animal adaptations, the causes of desertification, and strategies used to combat it. A case study of a specific desert (e.g., the Thar Desert or the Sahara) is usually required.

Worked example

Common mistakes

• 1Thinking all deserts are hot and sandy. Some deserts, like the Gobi Desert in Asia, are cold deserts, and many have rocky or stony surfaces rather than vast sand dunes (ergs).
• 2Assuming deserts are empty and devoid of life. Deserts support a surprising amount of biodiversity, with many species of reptiles, insects, and mammals, and highly specialized plants like cacti and acacia trees.
• 3Believing that desertification is the physical expansion of deserts. Desertification is the process by which fertile land becomes desert, typically as a result of human activities like deforestation, overgrazing, and inappropriate agriculture, especially in semi-arid areas bordering deserts.

Ecosystems: Hot Deserts exam questions

Exam-style questions for Ecosystems: Hot Deserts with mark-scheme style solutions and timing practice. Aligned to AQA, Edexcel and OCR specifications.

Frequently asked questions

• Why is it so cold at night in the desert?

  Deserts have very little cloud cover and low humidity. During the day, the sun intensely heats the ground, but at night, this heat radiates away very quickly back into space, with no clouds to act as an insulating blanket, causing temperatures to plummet.

• What is desertification and what causes it?

  Desertification is the degradation of land in arid and semi-arid areas, making it less productive and more desert-like. The main causes are human activities, including overgrazing by livestock, removal of trees for fuelwood, and unsustainable farming practices that exhaust the soil, all often exacerbated by climate change-induced droughts.