Apr. IS. 1930 Native Vegetation of Northern Great Plains 67 



was as abundant as in western South Dakota. Pound and Clements {4) 

 said in regard to buflfalo grass: 



The buffalo-grass was, until recently, supposed to have once covered the greater 

 portion of Nebraska; its disappearance has, as a matter of sentiment, been connected 

 with that of the buffalo. The patches of buffalo-grass, which are foimd scattered here 

 and there over the State, are to be regarded as intrusions rather than stragglers left by 

 a retreating species. 



Griffiths (2) says in regard to Bulhilis dactyloides : 



Bouteloua gracilis, especially when not in head, is very similar and frequently mis- 

 taken for it. On this account the true buffalo grass is very much overestimated in 

 importance, because there are so many things included with it in the popular mind. 

 Much of the credit given this species is due to the gramas, which in age especially 

 look much like it. On the other hand, the species is an important one throughout 

 its range. 



In southwestern South Dakota, at the Ardmore Field Station, where a 

 grazing experiment is now being conducted, the important grazing 

 grasses are Bulhilis dactyloides, Bouteloua gracilis, and Agropyron smithii. 

 This association is dominated by the Bulbilis. 



It often happens that a species that is of little grazing value in one 

 section is of value in another area. For example, Aristida longiseta is of 

 little grazing value at Mandan, since it is the last plant that cattle will 

 take even when the pasturage is short, as illustrated in Plate 13, B. 

 However, in other sections, Griffiths, Bidwell, and Goodrich (2) report 

 this species as being of considerable value. 



Some species are indicators of overgrazing, as Artemisia frigida at 

 Mandan. In pastures where this plant occurs in abundance it usually 

 will be found that the area has been overstocked for several seasons. 



In the vegetation of this area no poisonous plants are abundant 

 enough to be harmful. However, in areas farther west in North Dakota, 

 the common "loco weed" (Oxytropis lamberti) is abundant and causes 

 serious losses of stock in certain seasons. 



All the plants mentioned in the list on page 65 enter more or less into 

 the feed of grazing animals, but, as noted, only a few species produce 

 a considerable percentage of the total forage. One of the reasons for 

 this fact is the inability of many plants to produce more than a limited 

 second growth after they have once been removed by grazing. 



DENSITY OF VEGETATION 



In a consideration of plant density in relation to grazing problems 

 it is desirable and necessary to make clear and concise distinctions 

 between frequently recurring terms. Plant density should refer to the 

 "stand" or thickness of plants upon the ground surface. The ground 

 surface is the total area of land under consideration, whether vegetated 

 or unvegetated. Bare ground should be understood to refer to the un- 

 vegetated portion of the ground surface or the spaces in the cover between 



