Not all habitats are friendly. Earth is home to several "extreme" environments where mere survival is a constant struggle. Two such habitats are deserts and tundra, where extremes of temperature and rainfall are the norm.
Tundra temperatures can plunge to bone-chilling lows; deserts can go to either extreme—hot or cold. Many animals, such as the kit fox and the spotted skunk, have adapted to sizzling desert days by being active at night, when it's cooler. In summer, the Arctic fox may store food in tundra's permafrost, which freezes the food and keeps it available for winter when the ground is covered with snow.
Both deserts and tundra receive very little rainfall—usually as little as 10 inches (25 centimeters) a year. Desert plants may have to go without fresh water for years at a time, but their ability to adapt can boggle the mind. Some plants have roots that reach water deep underground. Others have shallow root systems that spread out near the surface and can soak up rain from passing showers.
Plants in the cold, northern desert-like tundra—ground-hugging grasses, sedges, shrubs, moss, and lichens—have adapted by remaining small, resistant to wind, and able to grow in poor soil.
Frigid or scorching temperatures and lack of water push wildlife to the very edge of survival in these lands of fire and ice. Yet they adapt. In Earth's harshest environments you'll find some of its most amazing plants and animals.
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Arizona-Sonora Desert Museum
Take virtual tours, learn about desert habitats, and more.
Biomes of the World: Tundra
Get the cold, hard facts on one of Earth's extreme habitats.
Deserts: Geology and Resources
Learn about the features and types of deserts around the world at this U.S. Geological Survey site.
DesertUSA
Learn about the animals and plants that live in U.S. deserts.
Sonoran Desert Conservation Plan
Print out coloring book pages, play games, take quizzes, and more.
Tundra: The Not-So Barren Land
Survival on the tundra isn't easy, but these plants and animals have it down cold.
