12 



Carbon and Nutrient 

 Budgets and Their Control in 

 Coastal Tundra 



F. S. Chapin III, P. C. Miller, 

 W. D. Billings, and P. I. Coyne 



INTRODUCTION 



Arctic tundra ecosystems are characterized by low productivity, 

 slow energy flow, slow nutrient cycling, and, in many cases, peat accum- 

 ulation, despite a diversity of parent material and variable species com- 

 position (Billings and Mooney 1968, Bliss et al. 1973, Rosswall and Heal 

 1975, Dowding et al. 1981). These common features derive in some 

 fashion from the low annual solar irradiance and consequent low tem- 

 peratures that prevail at high latitudes. Earlier chapters have shown that 

 most organisms inhabiting the wet meadow tundra have adaptations that 

 minimize the effect of low temperature upon vital processes. How then 

 do low irradiance and associated low temperature help to generate the 

 unique characteristics of coastal tundra, and to what extent are other fac- 

 tors responsible? In this chapter we summarize, from information pre- 

 sented in earlier chapters, pool sizes and average annual fluxes of carbon 

 and selected inorganic nutrients. Through comparisons with other eco- 

 systems we attempt to identify those aspects of energy flow and nutrient 

 cycling that are peculiar to the Arctic and consider the nature of causal 

 links with climate. 



STANDING CROPS 



Two sets of standing crop data are presented for Barrow. Pool sizes 

 and fluxes at the intensive study site in a Carex-Oncophorus meadow 

 were measured in considerable detail in 1970 and 1971(Figures 12-1, 12-2 

 and 12-3). Biomass was also measured in 1972 in all major microtopo- 

 graphic units and then weighted by relative abundance to give average 



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