Table 3 

 Abundance of Three Classes of Algae, Lake Mendota, Wisconsin 



Note: Readings for August were not available for the table. 



in February to 8.6 (surface level) in August and October. In Feb- 

 ruary, readings for carbonates at 21 meters have been as high 

 as 43 ppm. Fixed carbon dioxide is relatively high, 36-37 ppm. 

 Hardness is 163 mg. per liter (American Public Health Unit). Inor- 

 ganic nitrogen is 0.08-0.36 ppm, whereas total nitrogen varies from 

 13.1 ppm at the surface to 15.2 ppm at 22 meters depth (June). Sol- 

 uble phosphorus occurs in 0.01-0.02 ppm. Correlated with these 

 physical-chemical characteristics, the algal flora is predominantly 

 the cyanophyte-diatom type, although during summer months there 

 may be a dense growth of Staurastrum (a desmid genus), which 

 gives the Chlorophyta a larger representation as far as number of in- 

 dividuals is concerned. The over-all bulk of algal vegetation is not so 

 great in Lake Mendota as in some of the other bodies of water in the 



[18] 



