Fróðskaparrit - 01.01.2008, Síða 176

174
DISTRIBUTION AND THE IMPACT OF OUTFIELD DRAINACE ON CARABIDS
(COLEOPTERA, CARAB/DAE) IN NORTH WESTERN EYSTUROY, FAROE ISLANDS
salina, Patrobus septentrionis and Carabus
problematicus are the most abundant spe-
cies above 150 m altitude; Patrobus atroru-
fus is also quite abundant. Below 150 m
altitude Nebria salina, Patrobus atrorufus,
Carabus problematicus and Calathus fuscipes
were the most abundant species.
UD area
Fourteen species were found in the UD area
(Eiði 2) see Table 3. From Table 3 we see that
Nebria salina is the most abundant species
above 125 m altitude followed by Patrobus
septentrionis, Patrobus atrorufus, Nebria ru-
fescens and Trechus obtusus, which all have
an abundance between 8.2 and 11.5 percent.
Below 125 m altitude the most abundant
species are Calathus fuscipes and Nebria
salina; Carabus problematicus and Patrobus
septentrionis are also quite abundant
ND area
Thirteen species were found in the ND area
see Table 4. From Table 4 we see that Nebria
salina is the most abundant species above
157 m altitude, followed by Patrobus septen-
trionis; Nebria refescens, Trechus obtusus and
to some degree Notiophilus biguttatus are
also abundant. Below 125 m altitude Trechus
obtusus is the most abundant species fol-
lowed by Nebria salina and Patrobus septen-
trionis; Patrobus atrorufus is also abundant.
Influence ofaltitude
Calatusfuscipes was found to be significantly
more abundant at the lower altitudes, this
was seen both in the OD (P=0.000) and UD
(P=0.003) area see Tables 2 and 3. Both
Nebria salina and Nebria rufescens were
significantly more abundant at the higher
altitudes, this was seen in the UD area
(P=0.013 and P=0.015 respectively) and ND
area (P=0.007 and P=0.000 respectively), but
not in the OD area, see Tables 2, 3 and 4.
Patrobus atrorufus was also significantly
(P=0.002) more abundant at the lower alti-
tudes, this was seen in the OD area (P=0.043)
and ND area (P=0.003), but not in the UD
area, see Tables 2, 3 and 4. Patrobus septen-
trionis was found to be significantly
(P=0.0025) more abundant at the higher
altitudes in the OD area, but no difference
was found in the ND and UD area. Trechus
obtusus was found to be significantly
(P=0.006) more abundant at the higher alti-
tudes in the UD area, but no difference was
found in the OD and ND area. No other spe-
cies were found to have significantly different
distribution regarding altitude except Lori-
cera pilicornis which was found to be signi-
ficantly more abundant at higher altitudes;
but since we found so few Loricera pilicornis
(see Tables 2, 3 and 4), we decided not to
regard this result as valid.
Influence ofseason
Calathus fuscipes and Patrobus septentrionis
were both significantly (P=0.05 and P=0.000
respectively) more abundant in the early
part of the season; this was seen both in the
OD and UD area regarding Calathusfuscipes
and in all 3 areas regarding Patrobus septen-
trionis, see Tables 2, 3 and 4. Carabus proble-
maticus, Nebria salina and Notiophilus bigut-
tatus were all found to be significantly
(P=0.001; P=0.000 and P=0.001 respectively)
more abundant in the late part of the sea-
son, this was seen for Nebria salina in all
areas, for Carabus problematicus in OD and
UD and for Notiophilus biguttatus in ND and