V. A SKETCH OF THE CHIEF PLANT-FORMATIONS 



OF ICELAND. 



WE will now give a brief account of the commonest and, from 

 a geographical point of view, most important plant-formations 

 of the land-vegetation of Iceland, without, however, entering into 

 details or into local deviations of the different plant-associations. 

 This account is based partly on my own observations and partly 

 on those published by others; I have especially made use of Dr. 

 Helgi Jonsson's numerous excellent descriptions of the vegeta- 

 tion-forms of Iceland. Here I shall confine myself to the purely 

 geographical distribution without entering more closely into rela- 

 tions of causation, or into questions of general ecology, which will 

 no doubt be exhaustively discussed later on. The division into 

 plant-formations and -associations is as yet, in many respects, de- 

 pendent upon individual opinion. In the following, with the ex- 

 ception of a few deviations, I am adopting Dr. H. Jonsson's main 

 divisions. Dr. Jonsson is the most experienced investigator of the 

 vegetation of Iceland, and has described the plant-life from many 

 more parts of Iceland than has anyone else. But much work re- 

 mains to be done by future investigators ; the vegetation-conditions 

 from more than one-half the total area of the island are still to be 

 described, and so manv local variations, and such varied associa- 



/ 



tions occur within the larger formations that it will be a long time 

 before the details from everywhere are well-known. The following 

 is only a brief account for the general orientation of the larger 

 plant-formations and of the chief points regarding the distribution 

 of the higher plants according to present knowledge 1 . 



1 Besides the above-mentioned works on the flora of Iceland, there are the 

 following descriptions of the vegetation: Chr. Gronlund: Karakteristik of 



Plantevsexten paa Island, sammenlignet med Floraen i Here andre Lande (Natur- 

 historisk Forenings Festskrift, 1890 [printed 1884], pp. 107 145 . C. H. Ostenfeld: 

 Skildringer af Vegetationen paa Island (Botanisk Tidsskrift, XXII, 1899, pp. 227- 



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