100 

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 ^ 30 

 [2 20 

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I 90 

 O 80 



a. 70 



60 

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I 23456789 10 



0^ FOOT CANDLES 



Figure Legends 



Figure 1 . Photosynthesis-light intensity curves for (A) individual phytoplankton organisms and entire 

 phytoplankton populations (from Ryther, 1956) and (B) individual pine needles and entire seedlings (from 

 Kramer and Clark, 1947) . 



74 



