67 



TSI(AVG) and 5 were correlated with pH. Eunotia spp. (S-EUN) and 

 Gomphonema spp. (S-GOMA) composed a cluster that was 

 significantly correlated with percent-volume infestation, but plots 

 revealed that both of these taxonomic groups had low sedimentary 

 concentrations except for unusually high concentrations in Lake Carr. 

 Emergent biomass was significantly correlated with a cluster 

 composed of Asterionella spp., Aulacoseira islandica, Tabellaria 

 flocculosa and T. fenestrata as it was prior to partialling covariant 

 effects. Another cluster composed of Caloneis sp. A and Nitzschia 

 capitellata was correlated with emergent biomass, but these taxa 

 demonstrated opposite slopes over the range of emergent biomass. 

 None of the 66 remaining correlation coefficients between diatom 

 clusters and macrophyte variables was significant. 



Cluster analysis of diatom taxonomic groups based on annual 

 diatom accumulation rates produced 11 clusters. Four of these 

 clusters were significantly correlated with TSI(AVG), and three of 

 these plus a fourth cluster were significanly correlated with pH. Four 

 clusters were correlated with shoreline length and two clusters were 

 correlated with specific conductance. Of the 55 correlation 

 coefficients between diatom clusters and macrophyte variables, only 

 one correlation coefficient was significant. Floating-leaved biomass 

 was found to be negatively correlated with a cluster composed of 4 

 periphytic and 3 planktonic taxonomic groups (Appendix 3.8). These 

 diatom groups were used in a stepwise regression procedure to 

 predict floating-leaved biomass. 



The last cluster analysis was based on diatom accumulation rates 

 with the effects of TSI(AVG) and pH partialled out, and it produced 



