POLLEN-ANALYTICAL STUDIES 363 



Betula in contrast to the herb pollen (shaded) after the Cyperaceae pollen 

 have been subtracted (i^P-Cyp.). The diagram shows clearly the second great 

 5erj//a-maximum, whose optimum lies between H4 and H3, i.e. 4000-2700 

 B.P. The Betula dechnes thereafter toward the "landnam" but the herbs 

 increase (cf. Rosaceae). The Salix-c\iv\Q goes as high as to 10-20 per 

 cent in Skalholt, and the Gramineae make up 5-10 per cent. With the "land- 

 nam" the "wild" Gramineae increase very rapidly and are very characteristic 

 of the influence of man in Iceland. A similar increase of "wild" grasses was 

 found by Iversen (1934, 1953) in the vicinity of the Nordic ruins in western 

 Greenland, and by Thorarinsson (1944) in Thjorsardalur, southern Iceland. 



Column D shows the differentiated herb curve, calculated on the total 

 pollen minus Cyperaceae (ZT-Cyp.). The number of "anthropophilous" 

 plants increases. These are Polygonum (cf. aviculare), Caryophyllaceae 

 (cf. Stellaria media, cf. Cerastium caespitosum), Rumex, Compositeae, 

 Ranunculaceae, Galium (cf. verum), Plantago (cf. maritima) and new species 

 like Valeriana, Linum (one grain from Skalholt), Myrica Gale and Artemisia. 

 The last two plants do not grow wild in Iceland today, but have probably 

 been raised in older times as medicinal plants, or been used for the brewing of 

 ale. 



Another interesting plant is Horcieum, cultivated in Iceland during the first 

 centuries of historic times. After the fifteenth or sixteenth centuries Hordeum 

 was not grown any more in Iceland, perhaps because the cHmate became 

 worse or for some economical or other unknown reasons. At the end of the 

 seventeenth century the Gramineae-curve shows a new rise at Skalholt and 

 the small Cerealia-msiXimnm perhaps indicates attempts to raise crops. 

 Pollen of Elymus arenarius is a serious source of errors in studies of the 

 Cerealia, since this species grows all over the country today, in coastal parts 

 as well as in the highlands in loose eohan sand deposits. Hordeum and 

 Avena sativa thrive in Iceland today again. 



Plants which decreased after the beginning of the "landnam" besides 

 Betula and Salix, are the Rosaceae (Comarum and Filipendula) and the 

 Umbelliferae (Archangelica officinalis, Angelica silvestris). After the deflation 

 had cleared the soils down to the barren-ground moraines, pollen of Thalictrum 

 increases in many profiles. 



Column E indicates a relatively small long-distance pollen transport 

 of mainly Pinus and Alnus (ca. l%o). There is apparently much more of long- 

 distance transport in prehistoric times than later, perhaps because of the 

 higher pollen production in Iceland after the "landnam" or because of the 

 deforestation of the nearest countries: Iceland lies 1000 km from Norway and 

 800 km from Scotland. 



Column F concerns the evidence of spores. Filicales are decreasing with 

 the "landnam", but Selaginella (selaginoides) is increasing. The highest part 

 of the Atlantic SphagnutJi-nvdximum is clearly seen (300 -^ 60 per cent). 



