164 
Table 8 
Percentage distribution of vegetation types along four transects of 15,168 m in total 
length. Also shown is the distribution across sand dunes excluding free-water cover 
% of land cover). 
Designation from 
Vegetation types vegetation map~ 
Dryas integrifolia heath type F,—>F3 
Salix rotundifolia snowbeds Fyw9 
Dupontia fisheri brook/meadow S12>F 3,4 
type 
Eriophorum angustifolium 
polygon marsh type 
Pi43; 4d >F 2,8 
Carex aquatilis marsh type 
Sand dunes (Salix ovalifolia) 
Water 
Roads 
Lg>L,, or aeons 
D15—D17""* 
% of 
Webber/Walker Transect land 
scheme 1 2 3 4 Mean(SD) cover 
Types 1,2,3 6 5 1 8 5(2.4) 5 
Type 9 8} 05 — = 0.2 - 
Type 12 4 2) — Ald 4(4) 4 
Type 3 72 56 46 30 51(15) 52 
Types 4,5,6 8 23 41 50 31(16) 31 
Types 15,16,17 = = 
9 13 11 1 8.5(4) = 
1 1 1 ~ 0.7 - 
“See prefix and suffix descriptions, Webber and Walker (this volume). 
ee . 
Tentative numbers. 
Transects were established in mid- to late July 1972. 
SD, standard deviation. 
intervals to determine the vegetation types 
through which they grazed. 
In late June a preference was shown for the 
Dryas heath and the adjacent snowbeds. These 
communities were slightly elevated, were well 
drained, and provided an early source of cal- 
ciphilic vegetation composed of Carex scirpoidea 
on the heaths, with herbs, flowers of Dryas 
integrifolia and Saxifraga oppositifolia, \ichen 
and Salix rotundifolia in the more protected 
depressions. Later in the season (after mid-July), 
the Dupontia fisheri wet meadow was preferred, 
perhaps because it had then contained a rich 
variety of herbs, salices, and grass-like species. 
The combined observations of caribou dis- 
persion in relation to plant vegetation types for 
the 1972 field season are shown in Table 9. 
Thus, 42% of all animals were noted on the 
Eriophorum marsh, the most available com- 
munity (52%); almost 20% were grazing the 
Dryas heath/Salix rotundifolia snowbed com- 
munity, and 12 to 14% were grazing the other 
communities. An assessment of caribou disper- 
sion in relation to vegetation type was also 
available from the behavior study, and the distri- 
bution was confirmed. For example, 59% of 
caribou grazed the Eriophorum and Dupontia 
types; 15% grazed the Dryas heath and snowbed 
types; 8% grazed the Carex marsh, and 18% 
grazed the sand dunes. The latter observations 
were confined to periods of insect harassment. 
When distribution is expressed as a function 
of the availability of the vegetation type in the 
area, it is clear that the Dryas heath/snowbed 
and the Dupontia wet meadows’ were used at 
almost 3 times their availability and the sand 
dunes at almost 2 times their availability, while 
the main community, the Eriophorum marsh, 
was used almost in proportion to availability. An 
apparent discrimination against the Carex marsh 
was noted. However, the Carex marsh was not 
available for grazing early in the summer because 
of the high water levels in it, which suggests the 
type may not be as available as shown in Table 
7. From the above discussion, it is clear that the 
ratio of caribou dispersion in relation to vegeta- 
tion type (Table 9, column 13) should not be 
interpreted as showing grazing preferences with- 
out accounting for the seasonal trends in the 
vegetation types with respect to phenology, and 
the probable presence of a prime mosquito 
habitat. Thus, the evident lack of preference for 
