The frozen tundra regions of the world are home to billions of microorganisms that have adapted over thousands of years to survive and grow in the extremely low temperatures of the tundra. Each grain of soil found in the tundra holds billions of microorganisms that are fed by dead organic material.
The Earth has two areas known as the tundra biome, which are the Arctic tundra and the Alpine tundra. Both areas are known for their frost-molded landscapes; the soil of the tundra remains frozen throughout the year, with only the top layer thawing in the short summer season. The frozen soil of the tundra is known as permafrost. The growing season for the Arctic tundra has a summer growing season for plants of between 50 and 60 days, with temperature in the winter reaching minus 30 F and summer temperatures of between 37 and 54 F. The Alpine tundra covers areas at the top of mountains throughout the world, where conditions are too severe for trees to grow. In the Alpine tundra nighttime temperatures usually reach freezing and the summer growing season is longer, reaching around 180 days, according to the University of California Museum of Paleontology.
A number of types of microorganisms have adapted to life in the frozen tundra soil, these include bacteria, fungi, yeasts and molds. These microorganisms survive in layers of dead organic material, such as moss that provides nutrients to sustain life. Microorganisms are positioned at the bottom layer of the food web, feeding on the dead material that grows in the short summer growing season. For example, in the Arctic tundra yeasts survive by feeding on the nutrients, such as sugar and water, that are produced in the short summer season when the top layer of the frozen soil thaws.
During the summer growing season microorganisms become more active where they grow and feed and release carbon dioxide. At Colorado State University, scientists investigating the effects of climate change discovered that as the summer growing season is extended by the rising temperatures of the Earth, the release of carbon dioxide increases and may outstrip the amount of carbon that can be stored by the plants of the planet.
The maintenance and growth of microorganisms within the tundra is accelerated in the warm summer season. During the winter season, some forms of bacteria and fungi are capable of growing and maintaining cell development without large amounts of food to sustain them, and where carbon dioxide is released by these microorganisms it is stored in the frozen soil.