Flóra: tímarit um íslenzka grasafræði - 01.05.1967, Side 92

SUMMARY.
This fourth and last part of this paper deals with tlie following formations of
the vegetation in the central higland of Iceland: The shrub vegetation, the vegeta-
tion on open soil (Icel. Bersvæðisgróður) sucli as Clayey flats, the sand vegetation,
and gravelly flats vegetation. Then there is a short survey on the Tundra moor, and
finally Chapter IV which deals with the vegetation according to different height
above sea-level.
The shrub vegetation is divided into two formations; A. Salicetum phylici-
joliae with two sociations: S. phylicifolia-Deschampsia flexuosa soc. 80, and S. phyli-
cifolia-Carex Goodenoughii soc. 81. The Salicetum is only found in rather moist
soil, especially Soc. 81, and occurs rarely above ca. 400 m. B. Beluletum tortuosae
with three sociations: B. tortuosa-Deschampsia flexuosa soc. 82, B. tortuosa-Salix la-
nata soc. 83, and B. tortuosa-Deschampsia flexuosa-Vaccinium uliginosum soc. 84.
The observations are made at 430—500 m. above sea-level, and the localities are
among the highest places where continuous Betulashrubs are founcl in Iceland.
The Vegetation of open soils falls into three main formations: A. Clayey flats,
which are rare in the central highland. The only formation is Koenigietum islandi-
cae, with one sociation, the Koenigia islandica-Sedum villosum-Agrostis stolonifera
soc. 85. B. The Sand vegetation. Two sociations are described: Elymus arenarius-Fest-
uca rubra soc. 86 and Festuca rubra-Equisetum arvense soc. 87. C. In connection
with the sand vegetation, regrouith on two toind-eroded localities is described, and
an attempt is made to give a survey of the succession of the sociations. D. The
vegetation of gravelly flats is described, and a survey of the vegetation is given in
Tables XXXVII and XXXVIII. Four sociations are mentioned and described: Si-
lene acaulis-Festuca rubra soc. 88, Salix herbacea-Cerastium alpinum soc. 89, Thy-
mus arcticus Poa glauca soc. 90, and Dryas octopetala-Thymus arcticus soc. 91.
The Tunclra moor (Icel. Flá) wliich is identical with the Scandinavian and arc-
tic Palsenmoor, is described and compared with a Palsenmoor in Tornetrásk, Swe-
den. Some observations on the destruction of the Palsen are described and stated
that the Palsen will be destroyed as soon as the icecore in them melts away on ac-
count of warm summers. When the Palsen are sunk, the whole moor often will be
dried out, and the soil eroded away by the wind.
In the last chapter (IV) is given a short survey of the changes of the vegeta-
tion at ever rising levels at a single locality at Kjölur.
HEIMILDARRIT.
Hér eru einungis talin þau rit, sem beinlínis er vitnaS í í þessari ritgerð auk nokkurra
Flóra. En auk þessa hefur verið höfð hliðsjón flestra þeirra rita, sem getið er í bókaskrá við
fyrri ritgerð mína um hálendisgróður íslands frá 1945.
Auer, V. (1920): Úber die Entsteluing der Stránge auf Torfmoorcn. Acta forest. Fenn. 12.
Helsingfors.
90 Flóra - tímarit um íslenzka grasafræði