18 



BULLETIN 1405, IT. S. DEPARTMENT OF AGRICULTURE 



Table 4.- 



-Phenoloffical observations of plants on north and south slopes in 

 different forage types, 1920 





Plant observed 



South exposure 



North exposure 



Date of 

 obser- 

 vation 



Eleva- 

 tion 



Slope 



Devel- 

 opment 



of 

 plant 



Eleva- 

 tion 



Slope 



Devel- 

 opment 



of 

 plant 



May 10 

 Do.-.. 

 Do.... 

 Do.... 

 Do 



OAK-BRUSH TTPE 



Letterman needle grass (Stipa letter mani) ... 



Fendler blue grass (Poafendleriana) 



Wild geranium (Geranium viscosissimum) . . . 

 Snowberry (Symphoricarpos oreophilus) 



Feet 

 7,200 

 7,200 

 7,200 

 7,200 

 7,200 

 7,200 



7,200 

 7,200 

 7,200 



Degrees 

 18 

 18 

 18 

 18 

 18 

 18 



16 

 18 

 20 



Nu- 

 merical 

 ' value 

 17 

 35 

 14 

 10 

 16 

 15 



10 

 31 

 15 



Feet 



7,200 



7,200 



7,200 



7,200 



7,200 



7,200 



7,200 

 7,200 

 7,200 



Degrees 

 20 

 18 

 18 

 20 

 20 

 20 



17 

 20 

 20 



Nu- 

 merical 

 value 

 10 

 20 

 7 

 2 

 5 



Do.... 

 Do.. _ 



Douglas knotweed (Polygonum douglasii) . . . 

 Birch-leaf mahogany (Cercocarpus montan- 



6 

 3 



Do 





20 



Do 





8 









Do 



7,200 



18 



18 



7,200 



19 



9 





Streambank wheat grass (Agropyron ripar- 





May 20 



7,200 

 7,200 

 7,200 



18 

 18 

 18 



20 

 35 

 19 



7,200 

 7,200 

 7,200 



20 

 22 

 18 



7 



Do 





19 



Do 





11 









Do 



7,200 



18 



25 



7,200 



20 



12 









May 28 

 Do 



7,200 

 7,200 



18 

 18 



60 

 60 



7,200 

 7,200 



22 



18 



40 





42 









Do 



7,200 



18 



60 



7,200 



20 



41 





SPRUCE-FIR TYPE 



Violet wheat grass (Agropyron violaceum) ... 





July 1 

 Do 



10, 050 

 10, 050 

 10, 050 



10, 050 

 10, 050 

 10, 050 

 10, 050 

 10,050 

 10, 050 

 10, 050 

 10, 050 

 10, 050 



26 

 26 

 26 



26 

 26 

 22 

 20 

 25 

 25 

 25 

 26 

 26 



14 

 15 

 27 



15 

 16 

 13 

 18 

 19 

 24 

 17 

 13 

 18 



10, 050 

 10, 050 

 10, 050 



10, 050 

 10, 050 

 10, 050 

 10, 050 

 10, 050 

 10, 050 

 10, 050 

 10, 050 

 10, 050 



28 

 28 

 25 



25 

 25 

 20 

 21 

 26 

 26 

 26 

 26 

 23 



10 



16 



Do 



Fendler blue grass . ______ 



25 



Do.... 



Columbian butterweed (Senecio columbi- 



17 



Do - 



Douglas knotweed... — ... 



12 



Do.... 



Snowberry_- . . . 



7 



Do.... 

 Do . 



Spiked trisecum ( Trisetum spicatum) 



16 

 16 



Do.— 

 Do-_. 



Do.... 

 Do.... 



Nevada blue grass ( Poa nevadensis) 



Wine gooseberry (Grossularia inermis) 



Mountain elder (Sambucus microbotrys) 



Yarrow (Achillea lanulosa) ■ __ _ 



20 



14 

 16 

 14 





Average .. .. 





Do.... 



10, 050 



25 



17 



10, 050 



25 



15 





Wild geranium. .. .... ..... 





July 10 



10, 050 

 10,050 

 10, 050 



26 

 25 

 26 



21 

 26 

 20 



10, 050 

 10, 050 

 10, 050 



25 



26 

 25 



20 



Do.... 



Letterman needle grass . . ._ 



21 



Do.... 



Violet wheat grass ... 



20 





Average . _ _.. 





Do.... 



10, 050 



26 



22 



10, 050 



25 



20 





Y arrow. _ . . 





Aug. 10 



10, 050 

 10, 050 

 10, 050 



26 

 25 

 26 



68 



75 

 70 



10, 050 

 10, 050 

 10, 050 



26 

 26 

 25 



70 



Do.... 



Letterman needle grass 



75 



Do.... 



Violet wheat grass . 



70 





Average.. __ ... . . . 





Do.... 



10, 050 



26 



71 



10, 050 



26 



72 









RELATION OF EXPOSURE AND SLOPE TO RANGE READINESS 



Climate, because of its influence on plant growth, largely deter- 

 mines the time at wmich the range forage is ready for cropping. 

 Elevation greatly affects climate, and is of prime importance be- 

 cause there is often an altitudinal difference of several thousand feet 

 in a mountainous range unit. Exposure has a marked influence on 

 temperature and plant growth. 



