EFFECTS OF DIFFERENT SYSTEMS OF GRAZING. 



21 



the western needle grass. They also show to a limited degree the 

 effects of grazing upon the different species. Plate II, Figure 2, 

 and Plate III. Figure 1. show the native vegetation as it appeared 

 on the quadrats in the 100-acre and the 30-acre pastures, respec- 

 tively, in 1915. Plate III, Figure 2, shows the quadrat in the 30- 

 acre pasture after six years of severe grazing. 



■While maps have been made to show all species, two charts. Fig- 

 ures 7 and S. are included, which show only the blue grama and 

 western needle grasses. These are the two most important grasses 



Fig. 7. — Square-meter quadrat in the 100-acre pasture, showing the relationship of Bou- 

 teloua and Stipa. Charted near the close of the grazing season in 1916. Bouteloua 

 gracilis is indicated by B and Stipa comata by 8. 



from the standpoint of grazing, since they furnish the largest per- 

 centage of the feed. These maps were made in the 100-acre and the 

 30-acre pastures in 1916 and show the relationship of these grasses 

 before the effects of grazing had become apparent. There is con- 

 siderable difference noted between the same quadrats mapped in 1916 

 and 1920. 17 This difference is mainly in the size of the mats of blue 



17 The quadrat maps have been drawn free-hand. In 1918 a pantograph was obtained 

 and tested for charting. However, it has not yet been used for this purpose. Its use in 

 charting has been described bv Hill. See Hill. Robert R., Charting quadrats with a 

 pantograph. In Ecology, v. 1, pp. 270-273. 1920. 



