Photosynthesis 105 



TABLE 4-2 



Maximum Photosynthetic Rates of the Major Plant 

 Growth Forms Among all Biomes 



'Sestak et al. (1971). 

 Tieszen et al. (1981). 



'Kallio and Heinonen (1973), Oechel (1976), Oechel and Collins (1976), Oechel and 

 Sveinbjornsson (1978). 

 'Kallio and Karenlampi (1975). 



subarctic and antarctic mosses (Stalfelt 1937, Hosokawa et al. 1964, 

 Rastorfer 1972, Kallio and Karenlampi 1975). 



The proportion of shrubs decreases and that of graminoids increases 

 with increasing latitude in tundras. This may reflect the higher ratio of 

 potentially productive to supporting tissue (e.g. stems) in the graminoid 

 growth form. In Dupontia the leaf is obviously the most important pho- 

 tosynthetic component; however, other components (Figure 4-1) are 

 photosynthetically active and contribute to the total amount of carbon 



