Náttúrufræðingurinn - 1981, Blaðsíða 46

ásætugróðurs, sem háður er loftinu um
upptöku vatns.
í Austur-Skaftafellssýslu er ásætu-
gróður þroskameiri innan til í dölun-
um, þar sem vindáhrifa gætir væntan-
lega minna, en úti við ströndina. Einnig
fer það saman, að birki er þar þroska-
legra og skógurinn ekki eins þéttur og
fyrir opnu hafi.
HEIMILDIR
Baldursdóttir, Sigríður. 1980. Athugun á blað-
og runnfléttum í nokkrum skógum í A.-
Skaftafellssýslu. Rannsóknarverkefni við
Háskóla íslands, líffræðiskor: 26 s.
Degelius, G. 1957. The epiphytic lichen flora
of the birch stands in Iceland. Acta
Horti Gotoburgensis. 22(1): 1—51.
Kristinsson, Hörður. 1981. Additions to the
lichen flora of Iceland II. Act. Bot. Isl.
6: 23-28.
Lynge, B. 1940. Lichens from Iceland. I.
Macrolichens. Norsk Vidensk. Akad.
Oslo, skrifter. Math. Naturv. Kl. 7: 1 —
56.
SUMMARY
New or rare species of lichens on
birch in Austur-Skaftafellssýsla,
Iceland.
by Hórður Kristinsson and Sigríður Baldursdótt-
ir, Institute of Biology, Grensásvegur 12, 108
Reykjavík and Hálfdán Bjömsson, Kvískerjum,
A -Skaftafellssýslu.
In the summers of 1979 and 1980, seven
species of epiphytic lichens new to Iceland,
and several rare species were found in the
region of Austur-Skaftafellssýsla, South-
east-Iceland. All were growing on birch,
and some were widely distributed through
the area where suitable birch stands were
found. The species new to Iceland were
Bryoria fuscescens (Gyelnik) Brodo & D.
Hawksw., B. simþlicior (Vain.) Brodo &
Hawksw., Cetraria pinastri (Scop.) S. F.
Gray, Evemia prunastri (L.) Ach., Platismatia
glauca (L.) W. Culb. & C. Culb., Pseud-
evemia furfuracea (L.) Zopf, and Usnea sub-
floridana Stirt. Of other rare species Cetraria
chlorophylla (Willd.) Vain. may be mention-
ed, previously only found in one locality in
Iceland on rocks; Hypogymnia tubulosa (Scha-
er.) Hav., hitherto only found as an alien on
imported wood; and Parmeliopsis ambigua
(Wulf.) Nyl.
This region apparently has more favour-
able conditions for epiphytic vegetation,
than elsewhere in the country. This is
probably due to extreme oceanic climate,
providing the essential air humidity, com-
bined with suflicient wind shelter in the
valleys, which are surrounded by high
mountains at the edge of Vatnajökull Glaci-
er. The epiphytic vegetation was richer on
SW-facing slopes, than those facing the
dominating oceanic winds from E and SE.
188