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.
1(54
sven o. björkman
marina, Ruppin maritima, R. spiralis, Scirpus parvulus, Sc. maritimas,
Cakile maritima, 1 satis tinctoria and Myosotis baltica (see Eklund 1931;
Samuelsson 1934). Eklund (pp. 93 106) declares tliat the presence
of many species much farlher lo the norlh ön the Finnish side than ön
the Swedish side, is due to the direction of the currents in Ihe Gull’ of
Bothnia. Whether we presume a recenl spread of a species, or consider
it having already reached ils limit lo the norlh, we have to look upon
this factor as very imporlant, since these constaiit currents determine
the salinity of the surface water as well as its temperature. A limitation
of the distribution of Ch. tomentosa by a cerlain isohalin seems not to
exist. Though Ihe course of some isotherms might be interpreted
»favourably» (see »Allas der deutschen Seewarle», 1927), ihe
distribulion of the species in the Finnish Bay does not speak in favour of such
a schematic interpretation. Nor are we able to express any opinion ön
the distribution of the species in relation tf) Ihe pH-conditions in this
area as these are known from Buch (1945). — As all statements of
Ch. tomentosa in brackish water refer lo shallow localities, we have to
presume the considerable fluctuations of the sea level in Ihe inner
parts of the Gulf of Bothnia and the Finnish Bay being one of the
factors limiting Ihe distribution of such a species. — Beside all factors
mentioned above we must also presume Ihe solid freezing as limiting
Ihe distribution of some water plants in these cold parts of Ihe Baltic.
In fresh waters of Sweden, Ch. tomentosa (f. sta<jnalis = Cli.
cerato-phylla Wali.R.) occurs in the prov. of Skåne, Västergötland,
Östergötland, and Uppland, also in Öland and Gotland. In Finland we find il
in some small lakes in Åland (Cedercreutz 1936, p. 191) and also
at Borgå, but this statemenl seems to be doubtful. In Denmark it is
known only from fresh water, and il is not at all found in Norway
(Wahlstedt 1875 and 1909; Hasslow 1936). Three sheels with Ch.
tomentosa in Ihe Bolanical Museum of Uppsala have the annotation
»K r i s t i a n i a,1 Sept. 1881, L. ,1. Wahlstedt». However, this
state-ment is verv doubtful and might refer lo Krislian st a d (Skåne);
from this place and from the same linie several specimens of Ch.
tomentosa collected by Wahlstedt are lo be found in Ihe museums of
Gothenburg, Lund and Stockholm. The annotations ön the specimens
in Uppsala do not originate from Wahlstedt, who has written the
olbers. — Oulside Fennoscandia and Denmark the species is known
as an inhabitant of fresh water in Latvia, Lithuania, Poland, Germany,
1 K r i s I i a n i a is an earlier nanie for O s 1 o.
<< prev. page << föreg. sida << >> nästa sida >> next page >>
