150 F. S. Chapin III et al. 



FIGURE 5-5. Seasonal changes in concentrations 

 of total nonstructural carbohydrates (a), polysac- 

 charides (a), lipids (o) and sugars (•) in leaves of 

 Dupontia fisheri and in stem bases and rhizomes 

 of composite samples of all moist meadow 

 graminoids. Vertical bars indicate standard error. 

 (After McCown 1978.) 



area (Tieszen, unpubl.), populations show markedly similar TNC con- 

 centrations (Table 5-2). Total nonstructural carbohydrate concentration 

 tends to be higher in habitats with low tissue phosphorus and low pro- 

 duction. These observations suggest that Dupontia 's growth is limited 

 more strongly by nutrients than by carbohydrate availability. Computer 



