Cold Environment Characteristics & Interdependence Flashcards

All 7 cards in this deck

What is permafrost?

Permanently frozen ground, frozen for at least two years.

What is the active layer in a tundra soil?

The thin surface layer of ground that thaws in summer and refreezes in winter.

Give two climate characteristics of the tundra.

Long cold winters and short cool summers; low precipitation (under 200 mm a year) with dry winds.

Why are tundra soils thin and infertile?

Cold slows decomposition, so there is little organic matter, and permafrost keeps them frozen or waterlogged.

True or false? Tundra soils are often waterlogged in summer.

True. Meltwater cannot drain through the permafrost beneath, so only hardy plants like moss cope.

Why does thawing permafrost speed up global warming?

Frozen ground stores carbon from dead plants; as it thaws, carbon dioxide and methane are released, which causes more warming and more thawing (positive feedback).

How does a polar climate differ from a tundra climate?

Polar areas are colder and usually drier: in most places no month rises above 0 degrees C, winters are far colder than in the tundra, and most of the land is covered by ice sheets all year, so there is little exposed soil.