In this article we will know the most important characteristics, the origin, formation and importance of peat bogs as an ecosystem and in the formation of peat.
What are peat bogs?
Peatlands consist of a topsoil with a high organic content that is formed by the accumulation of large volumes of plant debris and partially decomposed organic matter. This organic material accumulates in an environment deficient in oxygen, high acidity and deficient in nutrients.
Peatlands by definition are natural ecosystems that have formed due to special and unique climatic, geographic and topographic conditions.
This accumulation of plants and plant material, due to certain biochemical and mechanical transformations together with slow and incomplete decomposition, forms a hard soil that can be used as fuel since it contains at least 50% carbon. This hardened soil or accumulation of plant material is known as peat.
Therefore, a peat bog is a geological formation, layer or stratum made up of remains of plants and plant material, which has been consolidated, thus forming peat. It can be said that the first material in the cycle of coal formation.
Brief characteristics
Actually, there is currently no agreement on the minimum thickness of the organic layer of the soil surface and the minimum percentage of organic matter among the different definitions of peatlands.
For example, according to the US Department of Agriculture Soil Classification, a peatland consists of an organic soil (Histosol) that has at least a minimum of 20% to 30% organic matter, and 60% it consists of clay. Other authorities have adopted definitions that a peat bog has an organic matter content greater than 30% and a thickness greater than 30 cm.
Origin and environment of formation of peat bogs
The global distribution of peatlands It is grouped into two main groups of biogeographic zones linked to particular climates and linked to the water balance. The first group originates from certain equatorial and tropical wetlands (Amazon, Indonesia and Malaysia, etc.). High temperatures prevail in these areas, but also heavy rains (several meters per year). Here the large forested peat bogs are formed.
The other group covers the middle or fairly high latitudes of the two hemispheres in a temperate boreal climate. They appear, for example, in Canada, the British Isles, Fennoscandinavia, the Baltic countries and Russia, or even Patagonia, Chile and the Kerguelen Islands.
No peat bogs in extreme climates, either in a desert that is too dry, or in very high latitudes and altitudes that are too cold
Peatlands in temperate, boreal and subarctic regions
In this type of environment it is the low temperatures that dominate especially in the long periods in winter. These low temperatures reduce the rate of decomposition and peat bogs are formed due to the decomposition of bryophytes (sphagnum mosses), grasses, shrubs and small trees.
In humid lowland tropics
In this environment the peat bogs are formed due to the decomposition of leaves, branches, trunks and roots that come from tropical forests in constant temperatures throughout the year.
In coastal areas
In coastal areas, the peat bog formation environment responds to areas of accumulation of organic material in restricted environments within the extensive mangrove swamps.
In general, all types of peat bogs are formed in environments with an accumulation of organic material that undergoes decomposition in the absence of oxygen.
Training conditions
Despite the great variety of environments in which peatlands are formed, things in common can be drawn to understand their formation. For example, they need sufficient water that it remains in the system; thus, in a hot climate, a lot of rain is needed, while in a cold climate, less precipitation is enough, because evapotranspiration is less.
Other favorable factors are topography and the nature of the mineral subsoil ;incoming water should be stored for a long time, not flowing too fast downstream or into a porous substrate.
At the local level, there are peat bogs on ridges or slopes, or in filter zones, but then the cloudiness or the contribution of sources are almost constant.
Importance of peatlands
Peat bogs are very fragile natural ecosystems that are home to unusual animal and plant species. Therefore, it is important to know their origin and function in order to care for and appreciate these ecosystems:
- Biological value : They are ecosystems where types of environments and endangered species (specific flora and fauna) are preserved.
- Hydrological value : they are integrated into wetlands that contribute to the hydrological balance of our regions. Like a great sponge, they retain water and redistribute it every month of the year.
- Scientific value : the very acidic nature of these formations prevents the decomposition of plants, thus favoring fossilization (pollens, spores, invertebrates and vertebrates), which makes it possible to trace the botanical landscape and climate of the last 15,000 years.
- Fight global warming : Peatlands on Earth store carbon and slow down the greenhouse effect. All the peat accumulated on Earth over millennia contains about 500 gigatonnes of carbon (5 x 1011 tons), the equivalent of seventy years of anthropogenic greenhouse gas emissions!
Peat bogs in coal formation
If we remember how coal is formed, we will see that this rock first begins with the accumulation of large volumes of organic material (mainly plant remains), then this organic material is gradually buried until it forms peat, then lignite, then coal, bituminous coal and finely anthracite.
The peat bogs they are part of the initial cycle in the formation of coal, just when large amounts of organic and vegetable material accumulate in the soil and in the formation of peat.