PAPERS ON AGRICULTURE 



93 



A greater resistance to frosts. 



All of these known changes would be expected to produce 

 an effect upon the vegetation. 



Investigations were begun at the Wyoming Experiment 

 Station several years ago (Wyoming Forage Plants and Their 

 Chemical Composition. Bulletins Nos. 65 ( 1905 ) ; 70 ( 1906) ; 

 76 (1908); and 87 (1911). Knight, Hepner and Nelson) 

 which seemed to throw some light upon the change in com- 

 position of plants with change in altitude. 



Samples of native forage plants were collected at various 

 altitudes, but otherwise under as near similar conditions as 

 possible. 



Table I gives the complete approximate analyses of some of 

 these native plants. 



TABLE I. 

 Mountain Timothy 



Year 



Altitude 



Ash 



Ether 

 Ext. 



Crude 

 Fiber 



Nitrogen 

 X6.25 



N. Free 

 Ext. No. Samples 



It will be noted that the nitrogen content increases with 

 the altitude, while there are no regular changes to be noted 



in the other plant constituents. As further evidence of the 



change in nitrogen content with changes in altitude Table 

 II is given. 



TABLE II. 



Name of Plant Altitude Year N. X. 6.25 No. of 



Samples 



Tufted Hair Grass 10800 1907 10.95 I 



Tufted Hair Grass 11000 1907 17.93 



Tufted Hair Grass 7200 1908 6.07 1 



Tufted Hair Grass 10500 1908 12.98 



Mountain Blue Grass 10000 1908 9.36 1 



Mountain Blue Grass 10500 1908 11.87 2 



Mountain Spear Grass 8000 1909 7.78 



Mountain Spear Grass 10000 1909 8.18 1 



Fine Topped Salt Grass 4300 1908 7.79 2 



Fine Topped Salt Grass 7100 1908 12.82 1 



Canadian Needle Grass 9500 909 7.79 2 



Canadian Needle Grass 10000 1909 11.21 1 



