In Greece, peat forms mainly in topogenous mires (fens) located in intermontane basins while no recent fens in paralic environments are known. The fens form by terrestrialization, i.e. by infilling of lakes, and/or by paludification, i.e. by flooding of flat areas due to the relative rise of the groundwater table. The main peat-forming plants are reeds and sedges; they comprise mainly Phragmites australis, Typha angustifolia, T. latifolia, Cyperaceae, namely Cladium mariscus, Carex spp., Scirpus spp., and subordinately Alisma plantago-aquatica, Lythrum salicaria, Iris pseudacorus, species of the genera Sparganium, Equisetum, Eleocharis, and Salix, as well as aquatic and subaquatic plants, such as Nuphar lutea, Nymphaea alba, species of Myriophyllum, Ceratophyllum, Potamogeton etc. On the mountains of the northern country part and at altitudes higher than +1400 m, some small transitional mires occur in hollows on the slopes around springs (spring and sloping mires). The vegetation cover consists of Sphagnum squarrosum, Sph. flexuosum, Polytrichum commune, Bryum neodamense, Calliergon sarmentosum, Mnium elatum, Philonotis fontana, Eriophorum latifolium, Carex spp., Equisetum spp.

Since ancient times, the Greek mires have been drastically changed by human intervention, which diminished their extent. The country is mountainous and fertile soil suitable for crop production is limited to the few plains. As mires and, in general, wetlands occupied a significant part of the plains, they were considered hostile environments promoting also malaria.

 The first interventions were undertaken some 3,500 years ago by the Minyans, the prehistoric inhabitants of the Kopais basin. They drained out and started cultivating the plain, which flooded again in the 15^th or 16^th century AD. Finally, in 1887, the area (~20,000 ha) has been drained permanently. In the dry seasons of the next years, the drained peat, up to 4 m thick, has been totally burned up by self-ignition.

 The drainage of wetlands was practiced to a larger scale during the 20^th century, especially in times when refugees came to Greece and the demand for agricultural land increased. Unfortunately, there are no accurate data about the extent of the drained areas over the country. It is estimated that in the time span from 1930 until the World War II, only in Macedonia, which was the richest in wetlands part of Greece, 94.3% of the area ever occupied by mires, i.e. around 93,000 ha, were drained out and cultivated.

 This kind of wetland amelioration for land reclamation was applied until 1970, when some environmental problems became evident. For example, the brackish soils of the drained lake and mire of Agoulinitsa were proved unsuitable for cultivation, the surface of the Philippi peatland rapidly subsided, and the organic matter of the Chimaditida fen disappeared. From that time on, a time coinciding with the begin of the general environmental awakening, the ecological value of the wetlands started being gradually recognized. Wetland amelioration was cancelled and discussions about conservation and re-wetting of already drained wetlands started.

The largest fen in Greece and the thickest one all over the world is the famous Philippi peatland (surface 55 km², peat thickness 190 m, reserves 4,300 million m³). The peat along the whole profile consists of reeds and sedges. It started accumulating during Cromerian around 700,000 years ago and continued up to the drainage of the peatland for agricultural use between 1931-44. Immediately after peat has been drained contraction began, resulting in the destruction of infrastructure works, such as bridges over canals, roads etc. In 1960, after only 15 years of cultivation, the former fen surface was already subsided to a maximum depth of 3.5 m. Actual data on the recent subsidence do not exist. Except of this enormous subsidence of the surface, which causes a continuous demand for the improvement of the drainage system and also the infrastructure, another serious problem is the decrease of the harvesting rates as a result of the intense cultivation. In order to keep crop production stable, the demand for continuously increasing amounts of fertilizers is necessary, which results in the increase of the production cost and the pollution of the groundwater.

In the seventies, the Greek Public Power Corporation (P.P.C.) planned to exploit this peat deposit up to a depth of only 15 m for electric power generation, but due to socio-political problems the project is still in abeyance. However, the discovery of the big lignite deposit of Drama in the north of the Philippi peatland makes possible a combined future exploitation. Between 1990 and 1993, the Public Mining Company (G.E.M.E.E.) produced small amounts of milled peat from a 10 ha pilot area and after mixing with Finnish and Russian bog peat sold it for agricultural and horticultural uses.

In the Nissi fen (surface 9 km², peat thickness 15 m thick, reserves 50 million m³) peat started accumulating since Late Glacial. In the late seventies, peat mining was planned in order to feed a thermoelectric power plant. Later on, plans were made to utilize peat for agricultural and horticultural purposes. Due to protests by the inhabitants both projects have been cancelled. The fen surface is rather intact and it is used as meadow and pasture.

Before 1930 the mire north of the Chimaditida Lake covered an area of 28 km². After the drainage, 25 km² of the whole area started being cultivated for corn and trefoil. Drilling carried out in 1975-76 resulted in the discovery of a peat formation up to 3.5 m thick with reserves of one million m³ of natural peat. Meanwhile, the organic matter is lost due to oxidation or self-ignition. Today, only some peatland relics exist, while the fen is restricted to a narrow zone along the north-western and northern shores of Chimaditida Lake. The helophytic communities consisting mainly of Typha spp. grow in the greatest part of the shallow lake resulting in its infilling. The process is accelerating by eutrophism, which is caused by the washing-out of fertilizers, insecticides, pesticides etc. used by the farmers in the surrounding land.

The Small Prespa fen (surface 4-km², maximum peat thickness 0.3 m) is located at the shores of the homonymous lake located in north-western Macedonia. The fen remains intact, because the broad area became a National Park since 1974, protected by the Ramsar convention. However, the lake and the fen suffer from eutrophism caused by the agricultural activities in the surrounding area.

The Kalodiki fen (surface 2-km², maximum peat thickness 10 m, reserves 5.5 million m³) is located in Epirus, western Greece. Between 1989-93, the general aridity in Greece, as well as the intense water pumping from surrounding wells, especially during summer, resulted in lowering of the water table about 2 m below the fen surface. The whole fen was dried-out every year during summer and autumn. Subsidence and self-ignition phenomena occurred on the fen surface, while fauna (beavers, carps, birds) was totally eliminated and flora was strongly diminished.

The Ioannina fen (surface 2 km², maximum peat thickness 2.5 m, reserves 1 million m³) is located at the northern shore of Ioannina Lake. Until 1991, both the fen and the lake have heavily suffered from eutrophism caused by waste disposal of the town of Ioannina into the lake. Since then a unit for treatment of wastes is in operation.

The Koroni fen (surface 1.2 km², average peat thickness 5 m, reserves 5 million m³) is partly covered by alluvial sediments. In 1950 the fen was drained and converted into agricultural land, mainly for growing corn.