Finally, measurements on a number of sites which have been under investigation in previous 

 years were conducted so that comparisons with past and current investigations could be drawn 

 (Fig. 2). 



Table II. Sites, plots and treatments employed during 1970 Barrow program. 



Plot no. 



Treatment 



Plot nn. 



Treatment 



Site 1 



106 Control 



107 Control 



111 Heated air (green house) 



112 Heated soil (hot pipe) 



113a Oil and fertilizer (5 liters oil/ m^) (20-10- 



113b Oil and fertilizer (5 liters oil/m^) (20-10- 



114a Oil (5 liters oil/m^) 



114b Oil (5 liters oil/m^) 



115 Intense physical disturbance 



116 Light physical disturbance 



Site 2 



201 Control (nondestructive) 



202 Control (nondestructive) 

 803 Control (nondestructive) 



204 Control (nondestructive) 



205 Control (nondestructive) 



206 Control (destructive) 



207 Control (destructive) 



208 Control (destructive) 



209 Control (destructive) 



210 Control (destructive) 



226 Clip and clear 



227 Clip and clear 



228 Clip and uncleared 



229 Clip and uncleared 



230 Mulch (light) 



231 Mulch (intense) 



232 Fertilizer (20-10-10) 



233 Fertilizer (8-33- 16) 



234 Wind (not sampled) 



235 Orazeci f^not sampled) 



236 

 Site 3 



301 



311 



312 



313 



314 



303 



305 



306 



315 



316 



317 



326 



327 



Site 4 



401 



402 



403 



404 



405 



406 



Site 7 



B 



C 



D 



E 



F 



G 



H 



I 



Grazed (not sampled) 



Control for oil 

 Oil (12 1iters/m^) 

 Oil (1.4 liters/ra^) 

 Oil (5 liters/m^) 

 Oil (0.7 liter/m^) 

 Track (Intermediate) 

 Track (wet) 

 Track (dry) 

 Not sampled 

 Not sampled 

 Not sampled 

 Not sampled 

 Not sampled 



Wet meadow 

 Polygon trough 



Meadow (tundra, low centered polygon) 

 Meadow (unpolygonized) 

 Polygon top (eroded) 

 Polygon top (not eroded) 

 (ponds) 



Control 



Control 



Phosphorus additions 



Oil spill 



Shallow pond 



Artificial thermokarst pit 



Control 



Control 



Modeling 



An important aspect of the integrated ecosystem research and its design is the interactions 

 of field observations, data synthesis and ecological modeling. Modeling is actively underway at 

 several distinct levels. The initial phase of modeling was the early formation of a word model - 

 a verbal description of the structure and function of the wet tundra ecosystem. The word model 

 is subject to a continuing process of expansion and revision as our understanding of the tundra 

 becomes more precise. The most recent version of the word model appears in Appendix B. 



The interrelationships between the major abiotic and biotic components of the wet, arctic 

 ecosystem are emphasized in the graphic model illustrated in Figure Bl (App. B). 



Interactions within and between the abiotic and biotic subsystems of the ecosystem are made 

 more explicit in Figure 6. This model reveals the important compartments which contain the bound 

 energy and nutrients of the system, and the pathways by which energy and nutrients are transferred 

 within the system. In some places, as in the well-studied terrestrial consumers, important species 



12 



