ORDINATION OF MACROINVERTEBRATE COMMUNITIES 



761 



13 



•l4 

 12* % 

 , 11 . 



10 



JUNE 



(a) 



11 14 



8« • ^.9 



12 



5 6 10 



•I • I / •! 



13 14 



X 



\. 



SEPTEMBER 





\ 



(0 



12 



^^•-/ 



4- 



8 10 ' 



/ .. 



AUGUST 



9 7 



3 

 4 1 



5 



W2 



(b) 



-•X 



\ 



Fig. 5 Polar ordination of Great Miami 

 River system macroinvertebrate communi- 

 ties for June, August, and September 1976. 

 Samples located in relation to two axes by 

 relative similarity (coefficient of com- 

 munity) to end-point samples; units of 

 ecological distance marked on axes are 10% 

 coefficient of community. The first axis is x, 

 and the second axis is y. Dashed lines 

 (August and September) £ire gradients of 

 pollution disturbance. 



