7 April 2012 What is Tundra?

We have used the word tundra just about everyday since I arrived at the study site, but what defines tundra? Why don’t we have tundra in other places? The tundra is one of the biomes on our planet. A biome being a large area where the climate, geography, and the organisms are generally the same. So the tundra is defined by these factors.

Arctic tundra is found in all of the land areas surrounding the North Pole. These are areas that have permafrost as a subsoil, and receive very little sunlight during part of the year. The word tundra means “treeless plain”. The soil will not support large plants such as trees in these flat lands. In fact, the numbers of species the tundra will support is typically low. The frozen ground will not let roots very deep, and the nutrients are kept locked up from the plants most of the year. Most of the plants that do grow are in a dwarf size and are composed of shrubs, sedges, grasses, mosses, and lichens. Some scattered trees may be found in areas of tundra.

As we have talked about, the area around Healy gets down to 4 hours of sun during the winter, and has permafrost. The ground however does thaw out at times here. The top lay, or the active layer, does go down to 50 cm. As it turns out, our study site is in an area of discontinuous permafrost. There are areas north and south of us that do not have permafrost. We are studying in this area because here we are on the edge of permafrost zone. The ground temperature is only a degree or so below freezing. In a world of climate change and warming, this is the place where change stands to be the greatest. We are already seeing a faster change in the polar regions than we are further toward the equator. Many scientists believe that when this area warms another 2-3 degrees, the permafrost will thaw much more and begin to release the stored CO2 in the soil through increased respiration.

It is not accident that Dr. Natali chose this place to study. We are here monitoring the permafrost and the tundra to look at how the balance of carbon will be affected. The tundra has been a carbon sink for what appears to be tens of thousands of years. Over that time the carbon in the dead organic material has been frozen in the ground. Warming may release that carbon, as CO2, faster than the plants can take it up, which in turn will turn this sink into a carbon source.

Why is there no tundra in Huntington Beach?