Type 3 vegetation of Carex aquatilis, Eriophorum 
angustifolium, Dryas integrifolia and several Salix 
species. 
The following dichotomous key, which is 
based on plant rather+than geomorphic or 
habitat parameters, illustrates the simplicity of 
the identification process: 
Key to the most common vegetation types 
of the Prudhoe Bay area 
1. Lichens abundant 
Lichens rare 
2. Many fruticose and crust lichens 
Mostly fruticose lichens ......... Type 2 
3. Dryas and/or Salix spp. abundant .. Type 3 
Dryas and/or Salix spp. rare ue 
Ame VIOSSEStaleh sku yn e.c een eee Type 6 
Mosses abundant 2 
5. Drepanocladus species dominant Type 4 
Scojplaiunmaominant ese eee Type 5 
We plan to develop a key to all vegetation types. 
Other functional keys using a variety of para- 
meters could be made, but we want to avoid 
mixing descriptors to reduce the problem of 
circular reasoning when maps are subsequently 
analyzed and used. Nevertheless, vegetation, 
habitat, and geomorphology are intimately inter- 
related, and it is difficult to map them separate- 
ly at this scale (1:3,000) because of the fine 
mosaic and patterning of this tundra. But we 
believe our method will allow a separate analy- 
sis. 
85 
We have set up and sampled a number of 
permanent vegetation plots in both disturbed 
and undisturbed areas. These plots will serve as 
baselines for any subsequent changes. We have 
also set up specimen plots of each vegetation 
type which can serve as training and reference 
samples for other potential vegetation users or 
mappers; these will also serve as permanent 
baseline plots. 
Mapping Method 
The maps were initially constructed in the 
laboratory using July 1972 CRREL, 1:3,000, 
black-and-white, air photographs on which 
major landscape units were then outlined. These 
units were identified on the basis of uniform 
tone, texture, and pattern. Each of these units 
was visited in the field, their boundaries checked 
and changed as necessary, and their vegetation 
and geomorphologic features described. The inti- 
mate interrelatedness of geomorphic and plant 
patterns makes it difficult to produce separate 
vegetation and geomorphic maps. Our map 
(Plate |), however, shows the prevalent or most 
abundant vegetation type for each landscape 
unit and also records the geomorphic features 
and other frequent vegetation types which occur 
within a unit. The vegetation and geomorphic 
record is given by a formula of letters and 
numbers. The numbers in the formula indicate 
the vegetation types. On polygonal ground the 
vegetation types are listed in 2 or 3 groups of 
microsites separated by semicolons (;). The first 
group is the vegetation on the polygon centers; 
the second, vegetation on the rims, and the 
third, vegetation in the polygon troughs. A dash 
indicates the absence of a group or microsite 
category. The letter for the most abundant 
vegetation type is underlined. The letters preced- 
ing the numbers in the formula indicate the 
geomorphic features of each map unit: P — 
polygonal ground; F — flat or gently sloping 
terrain where ice-wedges are masked or ill- 
defined; R — small ridges and hills; S — streams 
and stream margins; W — dunes; L — lakes and 
ponds, and H — pingos. Often a subscript is used 
to further define the geomorphic feature: F — 
flat polygons; L — low centered polygons; H — 
high centered polygons; M — mixed polygons; B 
— river bluffs; f — frost boils; s — sandy soil; t — 
thermokarst pits; and r — reticulate-ridged flats. 
