Full-text - Norsk entomologisk forening

Norwegian stoneflies II 227
Table XVII. The stonefly association at different altitudes and vegetation belts in area 5, Kautokeino
Lower
Higher
Vegetation belts Sub-Alpine Low-Alpine Low-Alpine Middle-Alpine
Siphonoperla burmeisteri
X
lsoperla difformis
X
lsoperla grammatica
X
Diura nanseni
X
Taeniopteryx nebulosa
X
Amphinemura borealis
X
Amphinemura standfussi
X
Amphinemura sulcicollis
X
Leuctra digitata
X
Nemoura cinerea
X
Nemoura flexuosa
X
Nemoura sahlbergi
X
Nemoura viki
X
Capnia pygmaea
X
Capnia-vidua
X
Nemoura avicularis X X
Nemurella picteti X X
Protonemura meyeri X X
Leuctra hippopus X X
Leuctra nigra X X
Capnopsis schilleri X X
lsoperla obscura X X
Diura bicaudata X X X
Arcynopteryx compacta X X X
Capnia atra X X X
Nemoura arctica X X X X
Number of species 26 11 4
from 26 to 11 species; above the Salix belt
the fauna were reduced to 4 species (Table
XVII). Three of these were the same species
taken in the corresponding vegetation belt in
south-eastern Norway, Diura bicaudata, Arcynopteryx
compacta and Capnia atra. The
fourth, N emoura arctica, is confined to northern
Norway.
Discussion of vertical zonations
In all three zonations there was a reduction
in species, generally paralleled by the reduction
in Salix vegetation along the streams
with increasing altitude and by the reduction
in organic allochthonous matter in the streams.
In all three areas there was a reduction to
one or two herbivorous species in streams
someway into the Middle-Alpine belt. These
were N emoura cinerea and Amphinemura
standfussi in south-western Norway, Amphinemura
standfussi and Capnia atra in 0vre
Heimdal and N emoura arctica around Kautokeino.
The zonation in area 1 showed that Capnia
pygmaea and Amphinemura borealis were
not present above the coniferous forest and
that Siphonoperla burmeisteri also seems to
belong to the same vegetation belt. These
species were not taken in the Sub-Alpine
belt of 0vre Heimdal, although they are all
taken in the coniferous forests in the surrounding
areas and in the rest of eastern
Norway. However, around Kautokeino all
four species were taken in the Sub-Alpine
belt, but not higher.
Horizontal distribution of species
The decrease in species from inner fjords of
Rogaland to the coastal areas which was
documented above was examined further from
1966 to 1971.
The intention was to choose streams where
all factors were as constant as possible, although
temperature varied greatly. The
temperature differences are shown in general
terms in Table XVIII.
Stream descriptions
The streams chosen were: Byrkjelandselva