Fróðskaparrit - 01.01.1998, Síða 302

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ENVIRONMENTAL CHANGEIN ICE-FREE GREENLAND: A REVIEW
Little information is available about the
history of the Greenland vertebrates (Ben-
nike, 1997), but the early-mid Holocene
non-marine fauna included reindeer, wolf,
arctic hare, Lapland longspur and stickle-
back. By the time of the arrival of the frrst
people at around 4.3 cal. ka BP, most, if not
all, of the present-day vertebrates had im-
migrated to Greenland.
The early Holocene non-marine inverte-
brate fauna included seven named insesct
species (Bocher and Bennike, 1996; Ben-
nike and Bocher, unpublished) and a num-
ber of named crustaceans and bryozoans
(e.g. Bennike and Funder, 1997).
Some species, such as the reindeer and
the wolf, could simply walk to western
North Greenland from Ellesmere Island in
Canada, across the sea that is covered by
fast ice during the winther. Other species,
such as most birds and butterflies, could fly
to Greenland. The wind could carry spi-
ders, small insects, spores and small seeds
to Greenland. Sea currents, aided by drift-
ing logs, sea ice, ice bergs and ice islands,
could carry some plants and animals to
Greenland. However, birds and storms, per-
haps in combination, are considered under-
appreciated dispersal vectors for vascular
plants and other organisms. Long distance
chance dispersal of species during the
Holocene rather than survival is also com-
patible with the rarity of endemic species
on Greenland.
The onset of the Neoglaciation has been
dated to around 4.5 cal. ka BP (Weidick et
al., 1996; Bennike, unpublished). Outlet
glaciers from the Inland Ice expanded, lo-
cal ice caps formed, and ice shelves devel-
oped in North and Northeast Greenland. In
Northeast Greenland some straits and
fjords became blocked, so that corpses of
marine mammals and drift wood could no
longer wash up on the shores. At the same
time, the relative sea level rose a few metres
(e.g. Bennike, 1987). Whereas the »Little
Ice Age« led to a marked growth of the
Greenland Ice Sheet and local glaciers, any
effects on the terristrial biotas have been
difficult to document, but it may have led to
wetter conditions (Bennike, 1992).
References
Bennike, O. 1987. Quarternary geology and biology of
the Jørgen Brønlund Fjord area, North Greenland.
Meddelelser om Grønland, Geoscience 18: 1-23.
Bennike, O. 1990. The Kap København Formation:
sttratigraphy and palaeobotany of a Plio-Pleistocene
sequence in Peary Land, North Greenland. Medde-
lelser om Grønland, Geoscience 23: 1-85.
Bennike, O. 1992. Paleoecology and paleoclimatology
of a late Holocene peat deposit from Brændevins-
skær, central West Greenland. Arctic and Alpine Re-
search 24: 249-252.
Bennike, O. 1995. Palaeoecology of two lake basins
from Disko, West Greenland. Journal of Quarter-
nary Science 10: 149-155.
Bennike, O. 1997. Quartemary vertebrates from Green-
land: a review. Quaternary Science Reviews 16:
899-909.
Bennike, O. and Bócher, J. 1992. Early Weichselian
interstadial land biotas at Thule, Northwest Green-
land. Boreas 21: 111-117.
Bennike, O. and Bocher, J. 1994. Land biotas of the last
interglacial/glacial cycle on Jameson Land. East
Greenland. Boreas 23: 479-487.
Bennike, O. and Funder, S. 1997. Macrofossil studies of
Holocene lake sediments from Jameson Land, East
Greenland. Geology of Greenland Survey Bulletin
176: 80-83.
Bennike, O., Bjórck, S., Bócher, J., Hansen, L., Heine-
meier, J. and Wohlfahrt, B. in press: Early Holocene
plant and animal remains from Northeast Greenland.
Journal of Biogeography.
Bennike, O., Hansen, K.B., Knudsen, K.L., Penney,
D.N. and Rasmussen, K.L. 1994. Quatemary marine