Only about three percent of the landmass on earth - that comes out to about 4 million km² - is covered with moors. As the graphic shows, the areas with the greatest amounts of peat formation are in Eastern North America, Northern Europe, Central Europe, and Western Russia. It is clear that moor formation is associated with high rainfall (SUCCOW, M. (2001)).
Peat is formed in growing moors, meaning that vegetation dies and is deposited. Due to the constant presence of water close to the surface, however, the plant matter does not decompose, but rather accumulates. More material is deposited than decomposed - meaning that material is always being added to growing moors. As a result of this process, 30 percent of the total carbon worldwide is stored in just 3 percent of landmass (in the moors). When wide swathes of moor dry up, these areas transform into sources of carbon, becoming detrimental environments. The presence of oxygen causes plant matter to decompose, thus releasing large quantities of CO2 and methane, which contribute to the greenhouse effect.
Natural moors are like water reservoirs, with the peat and vegetation retaining a great deal of water. They thus have a balancing effect on the environment. Drained moors, however, can be hazardous during the heavy downpours that tend to occur with increasing frequency. The drainage ditches act as canals, collecting rain and directing it. Furthermore, drainage also destroys the typical characteristics of the peat - it loses its high capacity for water retention, the peat becomes water-repellent, and it is no longer able to retain water. When the moors are dried out, vegetation native to the moor is also lost - peat mosses are capable of storing many times their own weight in water.
The closeness of standing water at or above ground level creates special conditions for the vegetation and animals living in moors, or wetlands to be exact, whether it is a meadow or marsh area, a swamp or bog. As a result, moors are inhabited by highly specialized organisms that will be unable to survive if external conditions are changed.
One example is the peat mosses located only in high moors. They require a place with high water levels all year coupled with an extremely acidic and nutrient-deprived environment. Sometimes peat mosses will even create these conditions themselves by releasing H+ ions into the surrounding water, thus further reducing the pH value and making the moor water even more acidic. In this way, peat mosses are able to gain an advantage over competing plants that are not able to handle these extreme conditions.
From a geological history point of view, moors are relatively young landforms - with the first evidence of formation from about 10,000 to 12,000 years ago - when masses of ice were receding in the Alps and Scandinavia. Since moor growth as well as vegetation composition depends predominantly on climatic factors such as temperature, humidity, rainfall, and evaporation, changes in climate conditions can be reconstructed based on analyses of peat. Plant matter in the peat can leave clues about the living conditions in the past. Since the exclusion of oxygen and the acidity of the peat tends to preserve things, pollen from grains has been identified in peat drill samples. This can provide information, for example, about the point in time when humans started engaging in agriculture in order to secure their survival. Approximately 600 finds of human remains have been documented in European moors (COLDITZ, G. (1994)). The majority of these people met a violent end.
Flower pollen found in peat drill samples have been completely preserved by the lack of oxygen and high acidity of the moor water. They are examined under a microscope and identified based on their characteristics. The depth at which the specimen was found also indicates the time at which the pollen was deposited. This can be used to draw conclusions about the vegetation of the past. Since flora always develops in tandem with the climate, it is also possible to reach conclusions about the climatic conditions of the time.