Climates and Ecosystems of the Planet
Dryland Climates and Desert Ecology
A closer look at the climatic mechanisms behind the world's arid zones and the specialized ecosystems that survive within them.
60-Second Review
Express reviewA condensed, point-by-point summary of the module, for reviewing right before a test or exam.
- Hot Desert versus Cold Desert Climates. Deserts split into hot (BWh) and cold (BWk) types under Köppen, defined by aridity, not just heat.
- The Subtropical High-Pressure Belt and Rain Shadows. Descending Hadley cell air near 30° latitude and mountain rain shadows both starve regions of rainfall.
- Desert Flora and Water-Conserving Adaptations. Desert plants conserve water through CAM photosynthesis, deep or wide roots, and rapid ephemeral life cycles.
- Desert Fauna and Nocturnal Survival Strategies. Desert animals avoid heat through nocturnality, burrowing, and physiological tricks that conserve every drop of water.
- Semi-Arid Steppe and Transitional Ecosystems. Steppe belts like the Sahel and Eurasian grasslands form a fragile, historically vital transition beyond true desert.
- Flash Floods and Ephemeral Desert Rivers. Rare, intense desert storms can turn dry wadis into sudden, dangerous floods within minutes.
- Desert Ecosystem Fragility and Human Pressure. Deserts recover from disturbance extremely slowly, making them acutely vulnerable to human overuse.
- Drylands and Global Dust Transport. Desert dust carried by wind travels continents, feeding the Amazon and shaping weather far from its source.
This module continues after "Mountain and Highland Ecosystems" in the syllabus. If you haven't reviewed it yet, it may help set the context.
Key points
11. Hot Desert versus Cold Desert Climates22. The Subtropical High-Pressure Belt and Rain Shadows33. Desert Flora and Water-Conserving Adaptations44. Desert Fauna and Nocturnal Survival Strategies55. Semi-Arid Steppe and Transitional Ecosystems66. Flash Floods and Ephemeral Desert Rivers77. Desert Ecosystem Fragility and Human Pressure88. Drylands and Global Dust Transport
Visual module map
1Hot Desert versus Cold Desert Climates
2Desert Flora and Water-Conserving Adaptations
3Semi-Arid Steppe and Transitional Ecosystems
4Flash Floods and Ephemeral Desert Rivers
5Drylands and Global Dust Transport
Alternative visual view: a simplified sequence of some of the module's key points, in their order within the syllabus.
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Further reading
Bibliography and cited sources used to create this module.
- Peel, M.C., Finlayson, B.L., and McMahon, T.A. (2007). Updated world map of the Köppen-Geiger climate classification. Hydrology and Earth System Sciences, 11, 1633–1644.
- Goudie, A.S. (2013). Arid and Semi-Arid Geomorphology. Cambridge: Cambridge University Press.
- Louw, G.N. and Seely, M.K. (1982). Ecology of Desert Organisms. London: Longman.
- Middleton, N. and Thomas, D. (Eds.) (1997). World Atlas of Desertification (2nd ed.). Nairobi/London: UNEP/Arnold.
- Yu, H., Chin, M., Yuan, T., Bian, H., Remer, L.A., Prospero, J.M., Omar, A., Winker, D., Yang, Y., Zhang, Y., Zhang, Z., and Zhao, C. (2015). The fertilizing role of African dust in the Amazon rainforest: A first multiyear assessment based on CALIPSO lidar observations. Geophysical Research Letters, 42(6), 1984–1991.
- Schmidt-Nielsen, K. (1964). Desert Animals: Physiological Problems of Heat and Water. Oxford: Oxford University Press.