228 abstracts: botany 



million cubic feet of water; at Cincinnati 190,000 million cubic feet; 

 at Evansville 322,000 million cubic feet. Preliminary investigation 

 during 1908 in the Kanawha River basin showed 17 reservoirs with a 

 total capacity of 280,000 million cubic feet, in that basin alone. 



At the present time the two methods that are most advocated for 

 the control of floods are reservoirs and levees. Before any method can 

 be selected as the best, full information must be available in regard to 

 the quantity of water carried by the Ohio and larger tributaries and its 

 distribution as to drainage area and time. A. H. H. 



BOTANY. — Indicator significance of vegetation in Tooele Valley, Utah. 



T. H. Kearney, L. J. Briggs, H. L. Shantz, J. W. McLane, and 



R. L. PiEMEisEL. Journal of Agricultural Research 1: 365^17, 



figs. 1-13, pis. 42-48. February 16, 1914. 



The types of vegetation in Tooele Valley were found to be so closely 



correlated with the soil moisture and salinity conditions as to be useful 



indicators of the crop producing capabilities of the corresponding types 



of land. This suggests the practicability of classifying land in this 



region upon the basis of the native vegetation. 



The presence of the Sage Brush {Artemisia tridentata) Association 

 indicates that the soil is readily permeable and well drained and that its 

 salt content is very low. The soils occupied by the Kochia (Kochia 

 vestita) and Shadscale {Atriplex confertifolia) Associations are usually 

 less permeable than the Sage Brush soil and are relatively free from salts 

 to a depth of one or two feet, while the subsoil is usually very saline. 

 Where these three associations occur the moisture supply is not sufficient 

 to maintain the vegetation in an actively growing condition throughout 

 the summer. The Shadscale and Kochia lands, owing to their low ab- 

 sorption, offer in this respect less favorable conditions than the Sage 

 Brush land. The Greasewood — Shadscale (Sarcohatus verrniculatus and 

 Atriplex confertifolia) Association is found upon soils which are strongly 

 saline nearly or quite to the surface and are usually moist throughout 

 the summer at all depths below the first foot. The Salt Flat vegetation, 

 which comprises such extremely halophytic species as Allenrolfea occi- 

 dentalis, Salicornia utahensis, and S. rubra, occupies land which is strongly 

 saline and usually very moist throughout the summer from the surface 

 downward. 



It remains to be determined whether these correlations hold good in 

 other portions of the Great Basin region. The evidence at hand indi- 

 cates that, with relatively little modification, they obtain throughout 

 much of the intermountain territory. T. H. K. 



