It is hard for us people below the tree line -- which is what we call the boundary between the thick spruce and larch forest of the taiga (right below tundra) and the openness of the tundra -- life without wood. Take a minute and look around you...Do you see lots of stuff made of wood? Now imagine what you would do without it!

But why is the Arctic tundra treeless?

Most people think it is the extreme cold which keeps the black and white spruce you find along the tree line at bay. But they are actually able to withstand temperatures down to minus 90 degrees F (-68 C). If next coming to your mind as possible factors limiting the growth of trees are wind and permafrost -- you are right. Notice how the trees on this painting look like one sided Christmas trees pruned to stand in a tight corner! It is the harsh, bitter and plentiful wind with its sharp crystals of ice that cuts and kills trees. If you look at the map you may notice that the tree line is not a straight line around the globe. It fluctuates, largely depending on the force of COLD winds…of which there are plenty in Inuit country!

Another important factor is the permafrost. Permafrost is the name for ground which is permanently frozen. Throughout the arctic tundra it is usually within 3 ft (1 m) of the top layer of soil and goes up to 3,250 feet (1,000 m) deep. The farther north you are the closer to the surface the permafrost creeps. As a result the trees are forced to anchor themselves with roots so shallow that eventually they are too week to prevent the tree from tipping over!

The most important factor though, is the lack of sunlight – the very short summer. A tree needs so many warm summer days of at least 50 F (10 C) to survive or actually to be able to grow, and only few of the hardiest trees can complete their annual growth cycle under the prevailing conditions in these areas.

That explains why the arctic tree line is a broad boundary sometimes many miles deep unlike the clear-cut alpine tree line you will find on most mountain sides.

Especially when you travel on a dogsled you are going at just the right pace to notice how the trees gradually get fewer and smaller and smaller. Some trees are only knee high and maybe 80 years old, but they have not had much time each year to grow! Finally the trees surrender and disappear.

Tundra actually covers a fifth of the Earth's surface! There are several different types of arctic tundra. Let’s take a look at the 3 you can meet most often.

The most "typical" one is sedge meadow which is found all across the lower Arctic. It looks like a normal grass field, but it is made up  mostly of "sedges" which are marsh plants, not grasses because it is so wet here. Each summer when the sun melts the snow and ice, the water cannot get away..because of the permafrost right underneath which acts like a barrier stopping the melting water from being able to sink underground.

This makes Tussock tundra the worst nightmare for hikers in the summertime as it is for a dog musher in the winter. Imagine this; tough clumps of marsh plants growing in clumps the size of basketballs attached to the ground by a flexible stalk so that when you step on top of them they TILT OVER, throwing you totally off balance. Now that’s a challenge.

Much easier is the Mesic tundra. Its nickname is Rock garden and as you probably guessed for a good reason, since it is mostly bare ground and rocks. Though in the summertime it is almost the prettiest form of tundra when covered in more than 100 species of blooming wildflowers.

Also very pretty is the Shrub Tundra which is characterized by an abundance of low-to-the-ground bushes, such as willows, cranberries and blueberries turning bright red, orange and yellow in the fall.

The high Arctic on the other hand is without much stuff as we enter the polar desert. The harsh climate and short growing season eliminate all but the hardiest plants of all: lichens. Growing on rocks and between stones it is still very colorful though. Water is unavailable here during most of the year. It is a cold desert that receives very little precipitation – in some places only 3 to 4 inches (7-10 cm) a year which is less than what falls at places in Sahara! And remember there is "no water" in the ground.. only frozen solid permafrost.

Because of the permafrost houses in the high Arctic cannot be built directly on top of the ground. If they were, then the heat from the house through the floor would melt the permafrost and the house would start to tilt or sink into the ground!

Permafrost is good for something though. It is a great, big deep freezer. If you need to store your meat, you "just" dig a hole. And you can find some pretty cool Ice Age mammals buried in here such as extinct horses and bison. Not long ago scientists even found a whole woolly mammoth buried in Siberia.