Náttúrufræðingurinn - 1963, Síða 14

8
NÁTTÚRUFRÆÐINGURINN
HEIMILDARIT - REFERENCES
Bjarnason, Hákon. 1944. Um útbreiðslu skóga og skógarnytjar. Ársrit Skóg-
ræktarfélags Islands, bls. 10—35.
Einarsson, Þorleifur. 1957. Frjógreining fjörumós úr Seltjörn. Náttúrufr. 26:
194-198.
Hannesson, Pálmi. 1958. Frá óbyggðum. 325 bls. Reykjavík.
Kjarlansson, Guðmundur. 1943. Árnesingasaga, bls. 1—250. Reykjavík.
— 1958. Langisjór og nágrenni. Náttúrufr., 27: 145—173.
Landnáma. 1948. 408 bls. Reykjavík.
Pálsson, Einar B. 1961. Séð og heyrt á öræfum. Fræðslulör Náttúrufræðifélags-
ins 18,—20. ágúst 1961. Náttúrufr., 31: 174—192.
Steindórsson, Steindór. 1944. Árnesingasaga, bls. 251—268. Reykjavík.
Sveinsson, Runólfur. 1958. Sandgræðslan 50 ára, bls. 255—276. Reykjavík.
Þórarinsson, Sigurður. 1957. Mórinn í Seltjörn. Náttúrufr., 26: 179—193.
— 1961. Uppblástur á íslandi í ljósi öskulagarannsókna. Ársrit Skógræktar-
félags íslands 1961, bls. 17—54.
SUMMARY
On the vegetation of the highland
by Sturla Friðriksson
University Research Institute, Department of Agriculture.
At the end of the glacial period when the main glacier was retreating to
the soutlieast from the highlands the sea level was standing up to 120 m
higher in the southern part of Iceland than at present.
At that time tlie inland district Kjölur was relatively low and was rather
easily invaded by the different species of the Icelandic flora. Thus the Elymus
arenarius found the access through the glacial outwash plains to become an
inland mountain plant.
The sea level dropped gradually wliile the reclaimed land which was level
and boggy was mostly invaded by grasses and sedges. On thc liighland and all
drier parts of the lowland, however, the Betula pubescens predominated,
with the upper limits at around 500 to 600 m. Above that line the highland
became covered with grasses while alpine plants grew on the higher moun-
tains.
At the time of thc settlement there was a great change in the vegetation
as the woods were burned ancl grazed. The cleared woodland had a fertile
virgine soil and was turned into a productive grassland. Tlie grassland, liow-
ever, deteriorated gradually and soil erosion started.
During the late middle ages there was a change towards a cooler climate
and an advance of the glaciers to a maximum presumably at around 1890.
It is believed that the Kjölur district is mainly eroded during this cool
period.