Rit (Vísindafélag Íslendinga) - 01.06.1939, Blaðsíða 18

18
Observation 6 was made on ”Eggjar” (Háin) on July
15th 1933, h. above sea level ca. 100 m. Observation 7 was
made on ”Stórhöfði” on July 14th 1933, h. ca. 100 m.
Observation 8 was made round ”Helgafell” on July 14th
1933, h. ca. 100 m.
1. The Lava (1—5). This peat formation is, as far as
regards the soil, dry, gravelly, and in many places only a
shallow layer on top of rock, but with a thick and loose
covering of moss. Most prominent are Empetrum nigrum
L. and Thymus serpyllum L. var prostrata Hornem., Poly-
gonum viviparum L., Salix herbacea L., Festuca ovina L.
and Anthoxanthum odoratum L. are also very prominent.
The biological spectrum shows a high A %, up to 46.7 at
the highest, and a corresponding Ch %, up to 45.6- The
high A3 %, 20.0—39.4, with the comparatively higher
E1 %, 5.4—21.5 is also noticeable; this is very much in
accordance with the great extremes of heat and cold to
which the dry soil is subject from day to day over the
summer and winter. Otherwise the Th % is low, but the
H and G % indifferent.
2. Peat formation not in the lava. Obs. 6 was made
in a smooth, tuftless peat formation; the soil is shallow
but covered with a thick carpet of moss. Other charact-
eristic plants like Elyna Bellardi (All.), Koch. and Festuca
rubra L. now appear. The biological spectrum does not show
any great changes from the one above. Obs. 7 was made in
a very tufty peat formation on deep soil and Elyna Bellardi
(All.) Koch. and Festuca rubra L. are still most prominent
but Agrostis canina L. is added to the number of character-
istic plants and the A % is much lower, down to 24.1 and
with it the Ch %, down to 21-5. Obs. 8 was made near the
lava in the deep soil overgrown with tufts around the hill,
i.e. Helgafell, and now Thymus serpyllum L. var prostrata
Hornem., Anthoxanthum odoratum L., Festuca ovina L.
and Luzula spicta (L.) D.C. are the characteristic plants.
If the peat formation in the lava and that not in the lava
are compared then the chief difference proves to be in the