CONTENTS (Cont'd) 



Page 



Primary production and vegetation 90 



Consumers 93 



Soil nutrients 94 



Microbiology 94 



ni. Bioenvironmental gradients 97 



Abiotic 99 



Producers 101 



Consumers 110 



Decomposers: Microbiology and nutrient cycling 113 



Soil microbiology 113 



Soil nutrients 117 



Nitrogen fixation - Alpine site 118 



Appendix A: Sampling schedule 123 



Appendix B: The Barrow word model 127 



Appendix C: Provisional checklist to plants found in the vicinity of Barrow and 



Prudhoe Bay, Alaska 131 



Appendix D; Barrow intensive site visitors- summer 1970 137 



Appendix E: Data processing and storage 139 



ILLUSTRATIONS 



Figure 



1. Location map of sites involved in 1970 field observations 3 



2. Location map of major study sites involved in the 1970 Barrow investigations . 7 



3. Major ecosystem sites investigated in summer 1970 8 



4. Site 2 9 



5. Site 1 10 



6. Major pathways of exchange of energy and nutrients in the wet arctic tundra 



ecosystem 13 



7. Aerial oblique photograph of sites 1 and 2 and Footprint Creek channel showing 



the snow cover on 4 June 1970 15 



8. Daily minimum, maximum and mean air temperatures, Barrow, Alaska 17 



9. Close-up of air canopy probes 18 



10. Progression of soil thaw on site 1 plots 23 



11. Progression of soil thaw on site 2 plots 23 



12. Plots of measured and computed soil temperature 25 



13. Plots of measured depth of thaw and computed thaw depth 25 



14. Seasonal primary production values, site 2 control plots, Barrow, Alaska .... 30 



15. Seasonal chlorophyll contents, site 2 control plots, Barrow, Alaska 31 



16. Seasonal phosphorus contents, site 2 control plots, Barrow, Alaska 32 



17. Seasonal nitrogen contents, site 2 control plots, Barrow, Alaska 33 



18. Seasonal LAI values, site 2 control plots, Barrow, Alaska 34 



19. The diurnal oxygen consumption rate for a lemming 44 



20. View of a site 2 clip and clear plot with emergence traps in opposite comers . 61 



21. View into partly opened greenhouse on site 1 61 



22. Close up of heated soil experiment 62 



23. Idealized section of heated soil experiment and plot of temperature fields at 



selected sample periods 62 



