Where are there tundras

Temperatures are frequently extremely cold, but can get warm in the summers. The temperatures are so cold that there is a layer of permanently frozen ground below the surface, called permafrost.

This permafrost is a defining characteristic of the tundra biome. In the tundra summers, the top layer of soil thaws only a few inches down, providing a growing surface for the roots of vegetation. Precipitation in the tundra totals to mm a year, including melted snow. That's less than most of the world's greatest deserts! Still, the tundra is usually a wet place because the low temperatures cause evaporation of water to be slow.

Tundras are classified as either Antarctic tundra, Alpine tundra, and Arctic tundra. The treeline is what separates the forest from the high-altitude, cold, temperate latitude tundras. Arctic tundras are found in the northern hemisphere, which have frozen ground supporting low growing plants. Antarctic tundras are mostly covered in ice, and found in the South Pole regions, including the South Georgia and Kerguelen Islands.

Alpine tundras are frost-free, but still cold temperatures persist, allowing only low-growing vegetation to grow, and are found in mountains worldwide. Historically, tundras have been inhabited by humans for thousands of years. The first tundra dwellers, which were an early human subspecies who also had body fur, were the Homo glacis fabricatus who lived in the low vegetation.

Then came the people from the many indigenous tribes of Asia, Europe, and elsewhere in the Northern Hemisphere. Some of these tundra dwellers were nomadic, while some had permanent dwellings. Russia has its own tundra dwellers called the Nenets, who live in the northern Russian Arctic. Norway and Sweden also have their nomadic tundra dwellers called the Samis, or the Lapps. Early research into the tundra had triggered significant modern interest in the people who have continually lived in these regions for generations.

You cannot download interactives. Extinction is the complete disappearance of a species from Earth. Species go extinct every year, but historically the average rate of extinction has been very slow with a few exceptions. The fossil record reveals five uniquely large mass extinction events during which significant events such as asteroid strikes and volcanic eruptions caused widespread extinctions over relatively short periods of time.

Some scientists think we might have entered our sixth mass extinction event driven largely by human activity. Our planet is dependent on an interconnected system. If we lose one species, how does that impact the whole system? What if we lose hundreds? Help your students understand the gravity of extinction with these classroom resources. Barren tundra lands are home to hardy flora and fauna and are one of Earth's coldest, harshest biomes.

Biomes are typically characterized by the resident biota within them. Currently, there is a disagreement in the scientific community about what exactly makes a biome. Join our community of educators and receive the latest information on National Geographic's resources for you and your students. Skip to content. Image Yukon Tundra A defining feature of the tundra is the distinct lack of trees.

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