88 
D or d indicates either heavy or light disturbance 
respectively, the nature of which may be further 
defined by a subscript: | — organic or inorganic 
litter from road construction; g — gravel, equip- 
ment tracks, dust from road; and i — areas of 
impounded water. The disturbance symbols may 
stand alone or follow the vegetation numbers. 
The following examples illustrate the nature 
and interpretation of the formulae: 
F,2,8 Flat terrain with frost boils supporting 
type 2 vegetation of Dryas and fruti- 
cose lichens and type 8 vegetation of 
Saxifraga oppositifolia and Salix 
reticulata; the latter vegetation type 
predominating. Familiarity with the 
vegetation and the region permits 
further interpretation that type 2 
vegetation occurs on stable surfaces 
while type 8 is restricted to the frost 
boils. 
Pi 1-73 A region of lightly disturbed, high 
center polygons with type 1 vegeta- 
tion of Dryas and crust lichens on the 
raised centers, with no distinct rims, 
and with type 3 vegetation of Carex 
aquatilis, and/or Eriophorum augustr- 
folium, and dwarf shrubs in the 
troughs. 
Discussion 
Vegetation. Neiland and Hok (this volume) 
and White et al. (this volume) have provided 
useful descriptions of the Prudhoe Bay vegeta- 
tion. The units presented here, although slightly 
different in content and concept, can be cross- 
matched with these studies. A detailed compart- 
son is beyond the scope of this report. Table 3, 
however, attempts a brief comparison of the 
units recognized by T. Skogland in White et al. 
(this volume). 
The 6 most common vegetation types occur 
along a complex site moisture gradient. This 
sequence from dry (Type 1) to wet (Type 6) can 
be seen in Table 3. A moisture ranking for all 13 
types reported here from dry to wet would be: 
Types 1 and 10, Type 8, Type 2, Type 9, Type 
3, Type 11, Type 13, Type 4, Type 12, Type 5, 
Type 6, and Type 7. This sequence is not linear. 
Fig. 1 shows the topographic and spatial inter- 
relations of each vegetation type. It shows that 
the principal environmental control on the veg- 
etation is site moisture as controlled by top- 
ography. 
There is a strong correspondence between 
the vegetation map and the soil map (Plate |) of 
the same area (Table 4). Admittedly, there is 
some circularity involved in the latter statement 
because the same photographic base and a land- 
scape unit approach was used for both maps, but 
the soil-vegetation and site moisture correspon- 
dence is inescapable. 
The vegetation at Prudhoe Bay can be relat- 
ed to that of the whole Coastal Plain (Wiggins 
1951; Britton 1957) and even with vegetation of 
other arctic regions; for example, the Eastern 
Table 3 
Approximate equivalents between the vegetation units used by White et al. (this volume) and 
those in this report. 
White et al. (this volume) Webber and Walker (this report) Notes 
Dryas integrifolia heath 
Eriophorum angustifolium polygon marsh 
Carex aquatilis marsh 
Salix rotundifolia snowbed 
Dupontia fisheri brook/meadow 
Salix ovalifolia sand dunes 
Type 1 very dry 
Type 2 dry 
Type 3 moist 
Types 3 and 4 extensive 
Type 4 wet 
Type 5 very wet 
Type 6 emergent 
Type 9 and/or 11 
Type 12 not extensive 
Types 15, 16, and 17 provisional numbers; not 
elaborated here 
