Full resolution (JPEG) - On this page / på denna sida - Sidor ...
<< prev. page << föreg. sida << >> nästa sida >> next page >>
Below is the raw OCR text
from the above scanned image.
Do you see an error? Proofread the page now!
Här nedan syns maskintolkade texten från faksimilbilden ovan.
Ser du något fel? Korrekturläs sidan nu!
This page has never been proofread. / Denna sida har aldrig korrekturlästs.
OBSERVATIONS (IN THE VEGETATION Ol- TUE VNTARCTIC SeA 253
The regional distribution of the marine Hora.
According to my observations on Antarctic algæ the classification
of Kjei.I.MAN 1 into three regions, littoral, sublittoral and elittoral may
be used (Kjellman first used the word Gebiet instead of Region »).
Other authors have a somewhat different opinion. It seems to me
natural that the tide must be of decisive importance for the limitation
of the littoral region. ROSENVINGE’ puts the upper limit where
vegetation begins, and this according to him is at high water mark at neap
tide; and the lower boundary then will be found at the corresponding
low water mark. For the Færoes BORGESEN 3 approves the same
limitation. I am not able to decide if these limits can be used in the
Antarctic too; I am obliged to follow the rough definition, i. e. littoral
region = the space between high and low water.
The sublittoral region extends according to KjELl.MAN 4 to a depth
of 20 fathoms, then begins the elittoral. ROSENVINGE (1. c. p. 237)
proposes to move the lower boundary down to the depth, in which
the macroscopic flora ceases; consequently the elittoral region supports
110 such vegetation. BøRGESEN (1. c. p. 749) is of the same opinion.
Concerning the conditions in the Antarctic Sea I will keep to the old
boundary, because of the Desmarestia-formation which characterizes the
sublittoral region in its old sense. I propose 40—50 meters as the
lower limit. Still deeper we find some spots with algæ, belonging
to an elittoral region.
The littoral region.
As mentioned above, this region is exposed to very pernicious
influences and is for the most part devoid of vegetation, just as
according to Kjei.i.man ’* in the Arctic Sea. On sheltered coast we find a
rather rich flora, at least on individuals, that seems to me superior
to that of Arctic, except on the coasts of Greenland and in Arctic
Norway. Certainly the tracts laid dry at low water, are not very rich,
but the numerous lagoons, pools and caves, where some water is always
1 Alg. Murin. Meer. p. 57.
2 Om algevegetationen ved Grönlands kvster Meddel. 0111 Grönland. XX.
Köbenhavn 1898), p. 189.
3 The algæ-vegetation of the Færöese coasts. (Botanv of the Færöes. iii
Köbenhavn 1905), p. 709.
4 Alg Murm. Meer., p. 57, Alg. Aret. Sea, p. 8
Alg. Aret. Sea. p. 9.
<< prev. page << föreg. sida << >> nästa sida >> next page >>
