No. 9 1998 ARC TIC IN SECT NEWS - Department of Biological ...

4 ARCTIC INSECT NEWS No. 9, 1998
FEATURE LOCALITY: TRUELOVE LOWLAND, DEVON ISLAND, CANADA
James K. Ryan
Ryan and Hilchie Biological Consultants Ltd., 8613 - 108 A St., Edmonton, Alberta Canada T6E 4M7
Truelove Low land, north coast of Devon Is land,
N.W.T., Can ada 75°33′N, 84°40′W
Tem per a ture (1970-73): 278 de gree days above
0°C, 75 days above 0°C, July mean tem per a ture
6.3° C.
Hab i tats: Mo saic of sedge-moss mead ows,
cush ion plant com mu ni ties, dwarf shrub
heath; beach ridges; hummocky tun dra;
lakes, ponds, streams; rocky coast;
Pre cam brian shield.
Veg e ta tion: 96 pe ren nial vas cu lar plant
spe cies, 182+ li chen spe cies, 126
di a tom taxa, 132 moss spe cies, 30
hepatic spe cies.
Ver te brates: 7 mam mal and 35 bird
spe cies (17-19 spe cies ac tu ally
nest ing), one fish spe cies.
In ver te brates, known spe cies: pro to zoans
61, platyhelminths 1, cestodes 4,
nem a todes many, ro ti fers 66,
annelids 7, tar di grades 13,
crustaceans 13, spi ders 10, mites 22,
Truelove Lowland is the most thoroughly
studied biological research site in the Canadian
Arc tic. The In ter na tional Bi o log i cal
Programme (IBP) studies conducted there from
1970-74, led by Lawrence C. Bliss, generated a
great range of ecological information. Centred
on the con cept of energy flow through this eco -
system, IBP investigations ranged from perma -
frost, soils and climate through plants, an i mals
and decomposers, and human impacts. The syn -
thesis of four field seasons of research was thor -
ough, com pre hen sive and compactly presented
by all participating investigators in the project
sum mary (Bliss 1977). Pre vi ous and sub se -
quent stud ies, many by former IBP participants,
have added significantly to the knowledge of
this site and of arctic science.
The Truelove Lowland (Fig. 1) is a 43 km 2
coastal plain, one of a series of five lowlands on
the northeast coast of Devon Island. The site is
bi o log i cally di verse com pared with the sur -
rounding lands, most of which are high pla teau.
The Lowland may be called an oasis of diver -
sity as it is representative of the especially rich
sites that form about 1% of the Queen Elizabeth
Islands land area. The tall est vegetation rarely
reaches 5 cm above dry soils—15 cm in mead -
ows—and consists mostly of sedges, mosses,
cush ion plants, prone woody shrubs and li -
chens. A variety of meadows dom i nates the
land, separated by more than 20 steps of relict
beach ridges cre ated as the Lowland uplifted
from the sea 9700-7500 years B.P. Devon Is -
land, 54,100 km 2 , has no permanent hu -
man residents.
Biota
The biota of Truelove, summarized in ap -
pendices of the project book (Bliss 1977), bears
review and updating.
The flora includes 96 species of perennial
vascular plants. Of these, 7 species were con -
sidered dom i nant, 30 common, 44 moderately
abundant, and 15 were rare. Diatoms were not
included in the appendices, but Wolfe and King
(1990) report 126 taxa from 29 genera and 7 or -
ders of freshwater diatoms at Truelove. There
were 132 species of mosses and 30 of he pat ics.
Lichens in clude 182 listed species, with sub se -
quent additions. Altogether 92 species of fungi
were iden ti fied from soils, dung, and other
sources. The age distribution of freshwater arc -
tic char was studied by James Trask. Thirty-five
species of birds were sighted on the Lowland,
of which 17-19 species ac tu ally nested during
1970-74. Mam mal in hab it ants con sisted of
musk oxen and fluctuating low pop u la tions of
arctic hare, groenland lemming and short-tailed