The Prudhoe Bay area, like other areas on the coastal plain of northern Alaska, includes 

 numerous ponds and lakes. The perimeters of many of these showed the effects of fertilization by 

 waterfowl. Eiders (Somateria) and old squaw (Cianguia hyemalis) were seen resting on the banks, 

 and feces of larger waterfowl were present in abundance. The vegetation of such areas showed a 

 lush, green moss layer and included a greater diversity and density of flowering plants than 

 adjacent nonfertilized tundra. Thus, the waterfowl must act as significant mediators of nutrient 

 exchange between the aquatic and terrestrial segments of the ecosystems. 



Soil nutrients 



The Prudhoe sites were selected to determine the seasonal variation in available soil nutrients 

 after disturbance. The sites were located adjacent to the BP Pit no. 1 discovery well (Fig. 34, 

 Location D). Three disturbed sample sites were randomly located on an abandoned winter airstrip 

 which was used for landing C-130 Hercules cargo aircraft. This had produced markedly minor 

 physical disturbance, although disruption of the surface organic matter layer was evident. Three 

 undisturbed (control) sampling sites were randomly located in an area contiguous with the airstrip. 

 Both groups of sites are located adjacent to the revegetation site (Fig. 34, Location E). 



Early, mid-summer and end-of-summer samples were obtained for the upper 15 cm of mineral 

 soil. Table XXXV gives results of the sampling. With the exception of the phosphate concentrations 

 at the 10 September sampling time, the soils from the disturbed site showed significantly higher 

 nitrate and phosphate concentrations than soils from the undisturbed sites. Although the disturbance 

 at the site sampled on 10 September was relatively minor, the surface thermal regime was undoubtedly 

 altered to the degree where increased soil temperature might be associated with an increase in 

 microbial activity. This would result in a more rapid turnover of nitrogen and release of phosphorus 

 in the disturbed sites as compared with the undisturbed, adjacent areas. Similar trends were sug- 

 gested on the controlled manipulations at Barrow. 



Table XXXV. Concentrations of selected nutrients in 

 disturbed and undisturbed tundra soils. 



mg nuthent/g dry wt ol sample 



♦Difference between control and disturbed means significant at 1% level as determined by 



I test. 



Microbiology 



MicrobiologicaDy, the Prudhoe Bay area at first glance has a tundra area considerably different 

 from that at Barrow. Three control areas and two revegetation areas were sampled adjacent to loca- 

 tions D and E (Fig. 34). Results are given in Table XXXVI. Except for minor differences in numbers, 

 the three control areas were identical mycologically. The oiled revegetation area and the revegeta- 

 tion area free of oil show striking differences from each other and from the control areas. The 



94 



