Fróðskaparrit - 31.12.2000, Blaðsíða 101

105
Dominant Species Abundance Related to
Environmental Factors on Rocky Shores in
the Faroe Islands
Títtleikin av vanligastu føroysku dýra- og tarasløgunum á klettastrond
í mun til ymisk umhvørvisviðurskifti
Tor Eiliv Lein', Leif Christian Stige2 and Grethe Bruntse3
1) Correspondence address: Marine Biological Station, Espelandsveien 232,
N-5258 Blomsterdalen, Norway. E-mail: Tor.Lein@ifm.uib.no Telephone: +47 55983961 Fax: +47 55983950
2) Division of Zoology, Department of Biology, University of Oslo,
P.O.Box 1050 Blindern, N-0316 Oslo, Norway. E-mail: l.c.stige@bio.uio.no
3) Kaldbak Marine Biological Laboratory, FO-180 Kaldbak, Faroe Islands
(present address: Kolstrup 44E, 6200 Aabenraa, Denmark). E-mail: Gbruntse@hotmail.com.
Úrtak
Upplýsingar um títtleikan av 22 dýra- og tarasløgum av
168 harðbotnsstøðum í sjóvarmálanum í Føroyum vóru
kannaðar við kanóniskari korrespondansuanalysu
(CCA) og líkum kanningarháttum. Kanningarnar vístu,
at alduábæri hevði størsta týdningin, meðan onnur við-
urskifti so sum lendi og hvar á firðinum støðimar lógu
eisini sýntust at hava týdning, møguliga í lutfalli til
ávirkan teirra í sambandi við alduábæri. Kanningamar
vístu eisini, at flóð og fjøra eins og streymur høvdu eina
ávísa ávirkan, meðan lendishall, horving og vernd á
staðnum ikki høvdu nakra ávirkan. Urslitini bendu eisini
á aðra ókenda orsøk til frábrigdið í úrslitunum. Víst
varð, at lívfrøðiligi ábærisstigin, sum Bruntse o.a. (1999
b) gjørdu úr somu dátum, líkist fyrstu ás í ’Detrended’
-korrespondansuanalysuni (DCA). Hesar kanningar
stuðla metingini av, at tann lívfrøðiligi ábærisstigin í
høvuðsheitum endurspeglar alduábærið.
Abstract
Abundance data on 22 species at 168 intertidal sites with
hard substrate in the Faroe Islands were analysed using
Canonical Correspondence Analysis (CCA) and related
ordination techniques. Wave exposure was shown to be
the single most important factor. Substrate type and the
position in fjords were the other major variables, possi-
bly related to their effects on exposure. Current and tidal
amplitude had minor effects. No effects were detected
from slope, aspect, or local protection. The results also
indicated the presence of an unknown factor responsible
for some of the variation. The biological exposure scale,
which was developed by Brantse et al. (1999b) and
based on the same data, was shown to resemble the first
axis in Detrended Correspondence Analysis (DCA).
The present analyses supported the interpretation that
the biological scale mainly reflects wave exposure.
Fróðskaparrit 48. bók2001: 105-124