Importance of mire protectionPrint
Mires are predominantly northern ecosystems, especially abundant in continental boreal and sub-arctic regions, but they are also found in the tropics (see figure bellow) The total area of boreal and sub-arctic mires is estimated to be 3,460 -103 km2.62 The global peatland area is about 4 million km2, but these estimations remain uncertain owing to different typologies in different countries. Europe has suffered the largest losses of mires, both absolutely and relative to its former mire extent. Approximately 80% of both the original tropical and non-tropical mires are still in a nearly pristine condition. Net peat accumulation may have stopped 25% of these pristine mires, both in permafrost and in tropical peatlands, because of natural processes and recent climate change. Peat is accumulating just on 60% of the former global mire extent.
Outside the tropics, human exploitation has altered 500,000 km2 of mires so severely that peat accumulation has stopped completely. The global mire resource is decreasing by approximately 0.1% net per year. 80% of global mire losses are attributable to the agriculture and forestry.
High population pressure and climatic suitability for agriculture have made Europe the continent with the largest mire losses. Peat has ceased to accumulate in over 50% of the former mire area. Almost 20% of the original mire area no longer exists as peatland. In many European countries 1 % of the original resource remains.
Lithuania has lost one third of its mires and peat accumulation is taking place only in ~27% of peatland area.
Functions of mires and peatlands
Production function of peatlands for human beings is well recognized. Peat is extensively used for agriculture, horticulture, energy generation, medicine etc. Other functions are much less recognized among people even though peatlands have a function in the regulation of essential environmental processes and life support systems i.e. in the maintenance of adequate climatic, atmospheric, water, soil, ecological and genetic conditions. They may provide clean water, regulate water flow, recycle elements and affect both local and global climates.
Mires act as sinks of atmospheric carbon dioxide and peatlands constitute large reservoirs of carbon and nitrogen. Because of their extent and the large volumes of carbon stored in their peat, mires and peatlands play a major role in the global carbon balance. At present approximately the same amount of carbon is stored in the world's peatlands as in the whole atmosphere. The dominant effect of peatland drainage for agriculture or cutting for energy production or other similar uses is that carbon dioxide is released and emitted to the atmosphere.
Mires have an impact on local climate as well as they have a specific microclimate, which often differs from that of their immediate surroundings. Their microclimate is characterized by a greater variation in temperature, higher air humidity, greater fog frequency and greater risk of night frosts compared with that of mineral soils. There are slight differences between the maximum temperatures and pronounced differences between the minimum temperatures of mires compared with surrounding mineral areas.
Mires impact local hydrology and hydrochemistry as well as soil conditions. They store ~10% of global fresh water resources. They have recreational, aesthetic and spiritual functions.
Mires and peatlands also provide home for numerous plant and animal species. Great number of them is rare or endangered.
Proper understanding and valuation of mires and peatlans is crucial. Their impact on Earth and human lives goes far beyond well known production function, thus need to be seriously taken into consideration while making any development decisions that might affect these functions.