156 F. S. Chapin III et al. 



TABLE 5-3 Correlation of Production Parameters with 

 Nutrient Composition of the Plant Part in 

 Tillers Sampled along a Moisture-Nutrient 

 Gradient 



Note: Numbers are correlation coefficients. 

 *Significant at the 0.05 level of probability. 

 tSignificant at the 0.01 level of probability. 

 Source: Calculated from Tieszen (unpubl.). 



with nitrogen concentration and negatively correlated with phosphorus 

 concentration (Table 5-3), whereas leaf length shows the reverse correla- 

 tion. No clear trend is evident with leaf number. This suggests that the 

 intercalary and rhizome meristems respond quite differently and perhaps 

 are limited by different nutrient balances. Apparently, leaf intercalary 

 meristems are stimulated by favorable phosphorus status and/or a low 

 nitrogen-to-phosphorus ratio. A high phosphorus content might be an- 

 ticipated in meristematic cells because of the high requirement for mem- 

 brane phospholipid and phosphorylated sugars. The high leaf meristem- 

 atic activity under such nutritional circumstances would lead to strong 

 apical dominance and could partially explain the concomitant low rates 

 of rhizome growth and vegetative reproduction. 



Translocation is inhibited by low temperature only temporarily, 

 even in temperate plants (Swanson and Geiger 1967). Temperature does 

 influence the rate of active loading and unloading of phloem cells, an ef- 

 fect that is indistinguishable from the temperature effect upon source 

 and sink strength (Crafts and Crisp 1971). In contrast to temperate 

 plants, Dupontia is capable of translocating ""C to root and rhizome pri- 

 mordia frozen in soil (Allessio and Tieszen 1975a), as discussed above. 

 Similarly, low temperature inhibits translocation of sugars from leaves in 

 C4 grasses growing at their upper elevational limit but not in alpine gram- 



