76 



P. C. Miller et al. 



-^---^ -| FIGURE 3-3. Seasonal progres- 

 sion of the development of the 

 foliage area index of leaves plus 

 stems o/Eriophorum angustifo- 

 lium, Dupontia fisheri, Carex 

 aquatilis, other graminoids, and 

 all dicotyledonous plants in 

 1970 and 1971. 



the horizontal (Figure 3-5). Carex was the most steeply inclined, with 

 most leaves inclined 80° to 90° from the horizontal, followed by Dupon- 

 tia with inclinations between 50 ° and 90 °, and Eriophorum with foliage 

 distributed almost equally through all leaf inclinations. The dicotyledons 

 and understory plants, for example, Salix pulchra and Petasitesfrigidus, 

 usually have more horizontally incHned leaves. By late July the canopy of 

 the grasses and sedges was made up of the leaves and stems of the in- 

 dividual tillers, each with four to six new leaves and the dead leaves of 

 past years. The density of individual tillers was 2600 to 4800 m"^ (Dennis 

 et al. 1978). 



Belowground live biomass was 5 to 10 times that above ground and 

 was concentrated near the soil surface. Over 50% was in the upper 5 cm 

 of soil and over 80% in the upper 10 cm (Dennis 1977, Dennis et al. 1978) 

 (Figure 3-6). In the upper 5 cm, stem bases made up 8 to 22% and rhi- 

 zomes 9 to 25% of the belowground biomass. The remaining biomass 



