Rit (Vísindafélag Íslendinga) - 01.06.1975, Qupperneq 15

than any other single area in the country. These districts are also
the most significant volcanic areas in Iceland. Plant remnants in
Icelandic peat have not been extensively studied. For the most part
it consists of Cyperacéa, moss remnants are slight and particularly
Sphagnum as compared with peat found in other countries. Still it
seems that Sphagnum is much more conspicuous in the lower layers
°f the peat than in those closer to the surface. This peat, however,
formed in the co-called earlier mire period at which time the
climate was both much warmer and more humid than it is now.
Knots from Salix and Betula nana are widely found in the peat,
and in most mires there are two log layers of Betula pubescens
which testify to warm and dry climatic periods. No research is
available which would indicate whether these log layers are as
distinctly separated everywhere in Iceland, and I remember that
Jn peat mires in Eyjafjörður logs could be found almost throughout
the peat layers, although the two forementioned layers contained
by far the largest quantity.
Soil
In Icelandic mýri tracts there is always a layer of soil, usually
0-5—1.0 m. in thickness, on top of the peat. According to available
chemical analyses it has been found to be high in potassium per-
centage, but poor in calcium, phosporus and nitrogen. Its ash con-
tent is high for the same reasons as apply to the peat. Bjöm Tóhann-
esson (1960, p. 42) states that the soil samples which he took for
research purposes were selected so “as to exclude, as far as possible,
'dluvial additions of mineral matter and the effect of volcanic ash
layers,” apart from that “most of the mineral matter contained by
these samples is presumably due primarily to loessial deposits and
to bog iron that is commonly precipitated at the surface when bog
water containing ferrous iron comes in contact with the atmos-
phere.”
The acid content of Icelandic mýri tracts is generally rather low,
although they are low in calcium percentage and the fluctuations
ln their acidity are rather slight. According to research conducted
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