Fróðskaparrit - 01.01.2008, Page 167

ÚTBREIÐSLA AV SVARTAKLUKKUM (COLEOPTERA, CARABIDAE)
/ ÚTNYRÐINGSEYSTUROY 0C HVUSSU ÁVIRKAST HON AV AVVEITING
165
Map 2. The map shows the locations ofthe pitfall-
traps. ES 1, ES 13 and ES 31 refer to the intakes at
the rivers where pitfall-traps were placed, these are
the localities from the OD area (Eiði-1). NS 53, NS
57 and NS 66 refer to intakes at the localitiesfrom
the UD area (Eiði-2). Ff 1, F/2 and Ff3 refers to the
intakes at the rivers in the the ND area (Eiði-3g).
Altitudes as in map 1.
drained (ND) area has been drained since
2000, and lastly Eiði 2 an undrained (UD)
area was examined (see Map 2). The drained
study sites are situated on the NW part of
the island Eysturoy, which is the next largest
island in the Faroe Islands. The drained areas
are used as catchment areas for a hydropo-
wer plant. The two drained areas face in dif-
ferent directions, the older drained area is
facing southwest, while the newer drained
area is facing northeast. The undrained area
is in direct continuation of the older drained
area, and thus also facing south west (Map
2).
The Faroe Islands are an archipelago sit-
uated between the Shetland Islands and
lceland (approx. 62°N, 7°W). There are 18
basaltic islands ranging in size from 1 to 374
km2 (total area:1400 km2), and the highest
peaks of the different islands reach 370-880
m a.s.l. The climate is highly oceanic. The
main vegetation types in the study areas are
heaths, moss heath, blanket mires and mires.
The geology of the areas is different, since a
geological intrusion a so called sill is the
major part of the undrained area. The area is
treeless as the whole Faroe Islands, and has
been treeless since the last iceage (Jóhansen,
1985). The warmest months in the Faroe Is-
lands are July and August with 11°C (low-
land), while February is the coldest with a
mean of 4°C (lowland). The mean precipita-
tion of the lowland is 1500 mm per year. The
mean precipitations reflect the topography
of the islands such that the costal area re-
ceive 1000 mm per year, increasing to more
than 3000 mm per year in the central parts
(Cappelen and Laursen 1998).
Sampling
To collect carabids we used pitfall-traps.
They were made of plastic-beakers (7 cm di-
ameter, 10 cm deep) containing 2 dl forma-
lin solution (3.5 % vol). The bakers were in-
serted into a hole, the upper edge at soil
surface level. A lid was placed over the cups
(we used stones), taking care that the lid did
not stop the insects from entering the traps
(Sutherland, 2002). It was decided to place
the pitfall traps along rivers. This is because
the riverside banks are likely much affected
by draining, since it is at the rivers that SEV
(National Electricity Supplier) has placed the
water intakes. Three rivers in each area were
chosen in a way that enabled us to place
traps as long as possible down towards the
coast-line, but so that we were still in the
outfields. At 5 or 6 altitudes a.s.l. stations
containing 5 pitfall-traps were placed on