Flóra: tímarit um íslenzka grasafræði - 01.02.1964, Page 50

andi, og allra efst er lítils háttar einikjarr (Juniperus communis).
Skjól og snjódýpt er hér meiri en títt er um þursaskeggsbrekkur, og má
raunar segja hið sama um bletti X. 2—3 sem eru á Skjaldbreið og Egils-
áfanga.
Lítill vafi er á að gróðurhverfi þetta telst til Kobresieto-Dryadion
(Nordhagen 1943 s. 573).
ON THE VEGETATION OF THE CENTRAL HIGHLAND
OF ICELAND
By Steindór Steindórsson, Akureyri College, Akureyri
This articlc is the first part of a paper dealing with the vegetation of the central
highland of Iceland. It is based on investigations rnade in the years 1940—1949 along
with some additions Irom recent years. The article is to be continued in the next
volumes of „Flóra“.
The areas wliich are described are shown in fig. 1.
The plant formations.
After a brief topographical survey the author goes on to describe the plant
formations as follows:
The freshwater vegetation (vatnagróður). An account is given of the vegetation
in some small lakes and pools, but no sociations are described. On the whole the
bigger lakes are very poor in vegetation, but in small pools the vegetation often is
comparatively rich. Over 500 metres above sea level the vegetation in lakes and
pools almost disappears.
The marsli vegetation (mýrlendi). Marshes are widely distributed over the area
investigated. They are divided into three main formations: the swamp (flói), the
inundated marsh (flæðimýri) and the bog (mýri).
The swamp formation covers by far the widest area of the marsh. The soil is so
wet that the surface is covered by water for the greatest part of the year, and the
water is mostly stagnant. In the swamp formation following associations are descri-
bed: a) Eriophoretum angustifoliae, sociations 1—5, b) Caricetum Lyngbyei, soc. 6—
10, c) Caricetum rostratae, soc. 11—14, d) Caricetum rariflorae, soc. 15. The Eriopho-
rum association is in the wettest soil and has the widest distribution, the C. rarillora
association is closely related to it, and might possibly be taken as a variant. The C.
Lyngbyei association has some relation to the inundated marsh and is rarely found
outside deltas, in lakes and pools. The C. rostrata association has its main distribu-
tion in the lower parts of the highland. Tliis formation grows in almost as wet a
soil as the Eriophorum association, but the water is not complctly stagnant as there.
The inundated tnarsh (flæðimýri). This type of marsh is only found on river
sediments and on the banks of lakes. When the formation is tully developed, Carex
Lyngbyei becomes dominant. In the liigliland the C. Lyngbyei association is very
48 Flóra - tímarit um íslenzka grasaeræði