Erkki Kivinen

Maapallon soista ja niiden käytöstä

Kivinen E. Maapallon soista ja niiden käytöstä.

Tiivistelmä

The estimates of the total of peatlands in the world have changed considerably during the past decades. In 1929 their total area was approximately 100 mill. ha, in 1964 112 mill. ha, in 1969 150 mill. ha. in 1974 230 mill. ha and in 1979 350 mill. ha. The recent estimate is 422 mill. ha, but also that seems to be too small, because tropical and arctic peatlands have not been fully included. Thus the current estimate for the total area of world’s peatlands would be ca. 450 mill. ha. The proportion of virgin, intact peatlands has diminished especially in areas of Iong traditions of peatland reclamation for agriculture or drainage for forestry or other forms of peat utilization. In many European countries only a very low percentage of the original peatland area has remained in more or less virgin condition, e.g. in East Germany (GDR) 2 %, Denmark 3 %, Poland 6 %, and West Germany (FRG) 9%. In Great Britain (30 %), Finland (42 %), Ireland (53 %) and Czechoslovakia (56 %) the proportion of virgin peatlands is greater, but also utilization plays a significant role. In the major peatland countries, the USSR, Canada, and the USA (incl. Alaska), still more than 90 % of the peatlands remain in virgin state. In the late 1970’s the total drained area for peatland forestry was 9.35 mill. ha and the annual increase 0.47 mill. ha, the total area of peatlands reclaimed for agricultural purposes was over 6 mill. ha and the annual drainage rate only 70 000 ha. In the USSR the peatland area used by peat industry is considerable, at 4.35 mill. ha, but the total of other countries is only 0.15-0.2 mill. ha. The total area of forestry, agricultural and industrial drainage, about 20-25 mill. ha, appears relatively small when compared to the estimated total area of world’s peatlands (450 mill. ha), but particularly in densely populated areas both in industrial and developing countries, the need for peatland conservation has been emphasized. The amount of peat in thick deposits (minimum depth varying from 1-2 m) in the four major peatland countries (the USSR, Canada, the USA and Finland) is ca. 300-400 x 109 tons at 40 % moisture content. Taking into account the other countries and unsurveyed regions we can estimate the world's peat resources at 400 bill. tons with an energy content of 5 x 109 GJ. Although the energy crisis has increased pressure towards intensive utilization of peat reserves, only part of the total amount is economically exploitable.

Vastaanotettu 31.10.2017 Julkaistu 1.1.1982

Katselukerrat 1259

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