^^ 



Figure 33. Close-up of the transect with the oil seep in the background. 



3. Transect 3 was at the lower part of the slope where only the Carex community was present. 

 The transect began at the edge d' the seep. This was the wettest of the transects. Figure 33 

 shows the areas adjacent to the transects and the seep. 



Each transect was sampled to determine plant composition and to gain information as to what 

 might be causing the change in vegetation types. The species present in the transect were identi- 

 fied and their numbers counted. To facilitate comparison, the transect was divided into four sec- 

 tions 1 meter in length and 30 cm in width. The soil was probed for thaw penetration every 25 cm 

 along each transect. Five-centimeter-diameter cores of soil were taken at each meter along the 

 transect. These cores were then analyzed fa the presence of hydrocarbons by the fluorometric 

 comparator method. In order to eliminate contamination from coring, samples were taken from the 

 center of each core after it had been split with a razor blade. 



A ten-point thermistor temperature recorder was placed on transect 1. The probes were installed 

 at meter and meter 4 along the transect, with three probes in frozen ground, two in tliawed ground, 

 two in the vegetation, and two on stakes 1 meter above the soil surface. Another probe was also 

 located in the seep. 



The following species were found along the three transects: Carex aquatilis, Arctagrostis 

 latifolia var. latitolia, Salix rolundifoUa, Poa arctica, Senecio atropurpureus subsp. (rigidus, 

 Ranunculus sulphureus, Hierochloe pauciflora, Petasites (rigidus, Salix pulchra, Stellaria longpipes, 

 and AJepecurus alpinus subsp. alpinus. Carex community which was predominant aU along the 

 lower portion of the slope as well as the seep (transect 3) was also dominant along the edge of 

 the seep in transects 1 and 2. 



The abruptness in the shift of communities was noted by the marked differences in the numbers 

 of plants of Carex aquatilis and Arctagrostis latifolia, especially between the second and third 

 section of transects 1 and 2, Large differences were also observed with several of the less-num- 

 erous members, specifically Senecio atropurpureus. 



83 



