No Httempt was made during 1970 to isolate and identify anaerobic microaganisms ; however, 

 in the buried organic layers of site 2 the anaerobic organisms appear to play a significant role in 

 the cycling of nutrients and the formation of organic matter. This observation was based upon 

 direct microscopic counts using aeridine orange. High numbers of viable bacteria were observed 

 but we were unable to culture them under aerobic conditions. Significant quantities of methane 

 may be produced by anaerobic bacteria which are decomposing organic matter at the bottom of the 

 thawed portion of the soil profile. 



Subsamples of soil were collected for caloric examination of the soil from many of the samples 

 which were used for microbial examination and respiration determinations. These values will be 

 useful in determining the total potential energy available to soil organisms. In the litter layer of 

 the intensive site 4015 cal/g dry wt soil were observed. 



Special emphasis was placed on that portion of the decomposer microflora which is capable 

 of decomposing cellulose, lignin, and water-soluble polyphenols. A large pwtion of the organic 

 matter consists of cellulose; therefore, many bacteria and fungi which are capable of decomposing 

 cellulose were isolated from site 2. The size of this population varied from 10^ to 10^ organisms/ 

 g dry wt of soil. Other selective media were used to isolate microorganisms which degrade lignin 

 or tannin; a variety of fungi were isolated which have that potential. The quantity and activities 

 of these organisms at the Barrow site are not known. 



One hundred selected bacterial cultures are being examined using a factor analytical approach. 

 These cultures will be compared at Uppsala with cultures gathered from the various IBP sites. 



Soil nutiients 



Paul Gersper* 

 Rod Arkley* 

 Hans Jenny 

 Arnold Schultzt 

 Fred Bunnel 



University of California 

 University of California 

 University of California 

 University of California 

 University of California 



Josephine Challinor 



Alex Simmon 



Karen Fuller 



R.E. Hughes, Sr and Jr 



University of California 

 University of California 

 University of California 

 Nature Conservancy, 

 Bangor, U.K. 



Little is known of the dynamics of soils in tundra ecosystems. Considerable changes un- 

 doubtedly occur in the concentration of available nutrients in the soil solution as a result of 

 fluctuations in soil temperature, moisture, and biological activity which occur during the active 

 season in arctic soils. The importance of soil dynamics in the tundra ecosystem, particularly 

 fluctuations of nutrient concentrations in the soil solution, is germain to our understanding of the 

 total ecosystem. The soil solution is the intermediary between the decomposers and the primary 

 producers and functions as an important, but complex, link between these two ecosystem components. 

 Activities of decomposers and primary producers have direct, dynamic effects on the properties 

 of the soil solution whUe fluctuations in properties of the soil solution have direct effects on the 

 decomposers and producers. 



The primary purpose of the soil nutrient studies was to determine the magnitudes and directions 

 of nutrient concentration changes in the soil solution and to determine quantitatively the relation- 

 ship between the soil solution and soil, decomposers, primary producers, and below-ground and 

 above-ground microenvironments. 



Studies of soil dynamics and nutrient cycling consisted of several coordinated parts: 1) chem- 

 ical, physical, and morphological measurements of soil cores (15-cm diameter by 5-cm depth inter- 

 vals); 2) chemical measurements of soil solution extracted from each soil core segment; 3) moni- 

 toring of soil moisture and temperature fluctuations from buried sensors; 4) chemical, physical, 

 and morphological measurements of 7. 5-cm and 15-cm diam soil-vegetation tesseras, by 5-cm depth 

 intervals; and 5) chemical analysis of soil core (15-cm diameter by 2.5-cm depth intervals) samples 

 from Schultz's gasline plots. 



* Principal authors 



t Not at Barrow during 1970 



5S 



