26 



Forest Club Annual 



to demonstrate the invasional aggressiveness which takes place 

 under conditions of average favorability in a single year. These 

 plots were denuded in September, 1913, and charted in August, 

 1914, the density and character of the vegetation at that time 

 being shown in the figures. 



The number of individuals on these plots emphasizes the 

 fact that the investigator is able definitely to follow the structural 

 changes only of a limited number of such units as shown. Prac- 



. Polygonum 

 A Achillea 

 T Taraxacum 

 S Sophia 



DENUDED PLOT NO. 18. 



Leg-end 



R Delphinium 

 C Chenopodi um 

 PI Plantago 

 S't Stipa 



K Trisetum 



G Galium 



A g Agropyron 



