To the north of the taiga, the tundra spread its expanses. The name of this zone came to us from the Finnish language. The word tundra is translated as "treeless, bare hill". In Russia, a similar name denotes sections of the plain on which neither trees nor shrubs grow. There are a lot of small ponds and swamps. The climate of this zone is quite severe. You can often hear: "Why are there many swamps and lakes in the tundra?" To answer this question is not so difficult.
The climate of the tundra
So, why are there so many swamps and lakes in the tundra? A large role in their formation is played by the climate of the area. A harsh and very frosty winter is observed here, which lasts almost 9 months. During this period, the air temperature often drops to 50 ° C below zero. The tundra soils freeze deep to great depths and simply do not have time to thaw in a short summer.
The plant world in this area is rather scarce. If in a typical tundra you can still find dwarf trees and mosses, then in the Arctic almost nothing grows.
As for precipitation, they are rare in this climate zone. Here they drop out to only 300 millimeters per year. In comparison, rainfall is much greater in tropical forests. Here they fall to 2000 millimeters per year. However, swamps and lakes are much smaller. What is the secret? Why are there many swamps and lakes in the tundra with such meager rainfall?
First reason
At the moment, there are three main reasons for this phenomenon. The very first is a fairly large amount of water. Vapors in the area from the surface of water bodies are insignificant. Of course, the sun in the tundra also shines, but there is no heat. But one of the conditions for the active evaporation of moisture is a rather high air temperature.
There is little rainfall in the tundra. But at the same time, this indicator exceeds the rate of evaporation. As a result, moisture accumulates on the surface of the earth and forms small lakes and swamps.
Other reasons
Tundra soils are infertile. Under the poor soil, due to the scarce number of plants, there is simply a huge layer of permafrost. Its thickness is approximately one and a half kilometers. This is also one of the main reasons that the tundra has a lot of lakes and swamps. Due to the frozen layer, melting snow in summer and precipitation are simply unable to penetrate the soil. As a result, moisture remains on the surface, swamping the area or feeding nearby lakes and rivers. It should also be noted that the tundra soils are clay and heavy in themselves. They pass moisture very poorly.
Another reason why there are many swamps and lakes in the tundra is the unique relief of the climate zone. This area is almost flat, and only in some places there are small indentations and depressions.