Greinar (Vísindafélag Íslendinga) - 01.01.1942, Qupperneq 28

Greinar (Vísindafélag Íslendinga) - 01.01.1942, Qupperneq 28
24 E ...................... 64.0 55.0 59.0 59.7 Ph ...................... - 0.8 1.0 1.1 Ch ...................... 9.0 15.8 17.0 15.2 H ....................... 56.0 53.0 52.0 52.4 G ....................... 16.0 15.4 15.0 10.6 HH ...................... 6.0 6.7 6.0 9.2 Th ...................... 13.0 8.3 9.0 11.5 This table shows, firstly that the flora of Æðey is much richer in southern species than the flora of ísafjarðardjúp and the flora of the country as a whole, as may also be expected for the island is all lowland, but it shows also a higher E% than the flora of Isafjarðardjúp 0—100 M. Then it is also noticeable how the Ch% is lower but the H%, Th% and G% higher in Æðey than in the other spectra. It is, therefore, possible to distinguish the flora of Æðey as especially southern and rich in Hemichrypto- phytes as compared with the West fjords and, indeed, with the country as a whole. The causes of this departure in the biological spectrum are to be found in the climate. The purely insular climate is very unfavourable to Chamaephyte vegetation. But probably the influence of the human habitation is still stronger in exterminating Ch. It is very noticeable, both in the spectrum and especi- ally in the aspect of all the vegetation of the island how much poorer it is in shrubby plants than the mainland on both sides, where the Chamaephyte associations are domi- nant over large areas and, at least at the upper end of the Djúp, the predominating plant associations between the mountains and the sea. I find it possible to conceive that the great number of Therophytes, on the other hand, is to be attributed to the human habitation, as among them are most of the species of weeds to be found in the gardens and cultivated meadows of the country, but, on the other hand, it is likely that the summer is longer here on the is- land than up on the mainland, or in other words that there are fewer night-frosts there, so that annuals find it easier to ripen their seeds here than elsewhere. It would be en-

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Greinar (Vísindafélag Íslendinga)

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