The Botany of Iceland - 01.12.1914, Page 50

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TIIORODDSEN
only 20°—25°, but upon the other side 30°—35°. There are, how-
ever, a few basalt mountains which are mucli steeper than this:
for instance Skessuhorn near Borgarfjörður, which has an inclination
of 48°. In the numerous erosion-channels on the mountain sides,
where gravel and stones are constantly rattling down and avalanches
are frequent, it is difíicult for the plants to gain foothold. The
ridges between the mountain streams are therefore more closely
covered with plants hut, as already mentioned, a continuous plant-
Fig. 13. Basalt mountains witli snow-wreaths (Isafjörður).
covering rarely extends higher than half-way up on the basall
mountains. In olden times the mountain sides were in very many
places clad with coppice woods, but these disappeared at an early
date, partly owing to the havoc wrought by sheep and partly to
man’s lack of foresight. Now only some stunted shrubby birches
are to be seen upon inaccessible cliffs, where they are beyond reach
of man and beast, even with the utmost exertion. Upon mountain-
sides deprived of their bircli-copses, avalanches of snow and stones
have sutfered no hindrance, so that all soil and plant-growth have
disappeared, thus turning the mountain-sides into naked, gravelly
and rocky slopes. In some districts such changes have taken place