Information Concept in Ecology 



159 



MEAN 



PHOTOSYNTHESIS 



PER UNIT 



ILLUMINATION 8 

 CHLOROPHYLL 

 ( gcal kcal"' ug"') 



(2,10,10.9) 



f-IO 



-5 



(2,2,3.9) (10,10,9.2) 



( 10,6,6.1) 



10,2,2.6) 



COLLECTION DEPTH (ft) 



Fig. 10. Photosyntliesis per unit illumination and chlorophyll as a function of 

 sample collection and suspension depths (means for ten experiments). 



To test the significance of these relationships, the vertical co- 

 ordinate of the Figure 10 points was divided into that of the 

 Figure 9 points to obtain the ixiean chlorophyll concentrations 

 required to give unit efficiency: 4.86, 4.41 and 4.05 /xg", respec- 

 tively, for samples collected at 2, 6 and 10 ft. These values indicate 

 less chlorophyll to be required as sample depth is increased. Only 

 the first two means were significantly difTerent, however, estab- 

 lishing that the chlorophyll at 2 ft. was less efficient that that at 

 6 ft. Because of the high variance associated with the 10 ft. samples, 



