Contents xvii 



8: The Microflora: Composition, Biomass, and Environ- 

 mental Relations 255 



F. L. Bunnell, O. K. Miller, P. W. Flanagan, and 

 R. E. Benoit 



Introduction, 255 Taxonomic Structure: Its General 

 Character and Heterogeneity, 257 Microflora Biomass: 

 Its Distribution in the Environment and Changes 

 Through Time, 268 Environmental Controls on 

 Microfloral Biomass, 281 Summary, 288 



9: Microflora Activities and Decomposition 291 



P. W. Flanagan and F. L. Bunnell 



Introduction, 291 Potential of the Microflora to Utilize 

 Substrates, 294 Abiotic Variables and Microflora Ac- 

 tivities, 298 Decomposer Activities and Decomposition, 

 309 Summary, 333 



10: The Herbivore-Based Trophic System 335 



G. O. Batzli, R. G. White, S. F. Maclean, Jr., 

 F. A. Pitelka, and B. D. Collier 



Introduction, 335 Herbivory at Barrow — Lemmings, 337 

 Predation on Lemmings, 360 Factors Influencing Lem- 

 ming Populations, 371 Herbivory at Prudhoe Bay — 

 Caribou, 384 Comparison of Grazing Systems, 399 

 Summary, 409 



11: The Detritus-Based Trophic System 411 



5. F. Mac Lean, Jr. 



Introduction, 411 Abundance and Biomass of Soil In- 

 vertebrates, 412 Life Cycles of Tundra Soil Inverte- 

 brates, 424 Energetics of Soil Invertebrates, 432 

 Energy Structure of the Detritus-Based Trophic System, 

 436 The Role of Soil Invertebrates in Nutrient Cycles, 

 441 Abundance, Productivity, and Energetics of Avian 

 Insectivores, 444 Summary, 456 



