323 GRAZING INDICATORS. 



New investigations. In connection with grazing studies throughout the 

 grassland and scrub cUmaxes of the West, it is proposed to extend experi- 

 ments in reseeding and transplanting to all the associations. These are being 

 established with especial reference to the prerequisites discussed and they 

 have been planned for the next four or five years in the expectation that these 

 will constitute the wet phase of the cycle. Protection and eradication have 

 been emphasized, and particular attention has been devoted to methods of 

 evaluating the r61e of competition, since actual practice will require the re- 

 seeding of both bare areas and overgrazed communities. This is done in 

 protected inclosures, where tillage methods may be employed in so far as 

 desirable, and where permanent quadrats can be maintained for charting 

 changes in composition and measuring the annual variations in yield (Cle- 

 ments, 1917, 1918, 1919). By the use of transplanting in addition to reseed- 

 ing, it is expected to determine the ecological requirements of practically all the 

 dominants and many of the subdominants, within the same association or 

 local grouping, as well as between associations. 



In addition to improving the carrying capacity of overgrazed areas, it is 

 hoped that it will prove possible to extend and develop mixed grazing types, 

 such as the mixed prairie, and the mesquite and sagebrush savannahs. The 

 mixed prairie has the highest carrying capacity of all grass types, and also 

 possesses essentially the same high resistance as the short-grass plains to 

 trampling, overgrazing, and drought. It owes this property especially to the 

 presence of buffalo grass, Bulbilis dactyloides. The runners of this grass make 

 it one of the very best for transplanting experiments and it should prove 

 possible to estabhsh sods as centers of ecesis throughout the grassland where 

 the rainfall ranges between 15 and 30 inches. Hilaria cenchroides has similar 

 values, but its range is more restricted and trials with it should perhaps be 

 confined to the Southwest. The production of mixed prairies, and of all 

 mixed types indeed, contains promise only in those climates or edaphic regions 

 where there is some water-content in excess of the needs of the existing domi- 

 nants. For this reason, it is practically certain that success can be attained 

 only by transplanting short-grasses into tall-grass areas, or into existing mixed 

 areas, rather than the reverse (plate 84). 



The value of mixed grass and palatable scrub in permitting the grazing of 

 cattle and sheep, often with goats, and in providing a double insurance against 

 drought or other disaster is so great that the possible extension or production 

 of such types is of the greatest importance. In many cases it is expected that 

 the carrying capacity of the type will be increased by replacing one shrub 

 with another more palatable. Where savannah already exists or desirable 

 scrub is already in contact with grassland, the extension of the scrub can be 

 secured by a system in which grazing and fire are used to maintain the balance 

 at the point desired. Fire in conjunction with planting furnishes a ready 

 means of developing grassland in the midst of scrub. The actual planting of 

 shrubs in grassland is more difficult because the demand for water then tends 

 to exceed the climatic supply. As a matter of fact, the demands of shrubs 

 and tall-grasses are so nearly alike that shrubs can be readily introduced into 

 true, subclimax, and mixed prairies during wet periods, as nature has often 

 proved. Once estabUshed, their deeper root-systems and taller stems enable 

 them to persist. Certain subclimax shrubs, such as the saltbushes, will 



