REPRODUCTION OF WESTERN YELLOW PINE. 



33 



Soil No. 28. 



description of soil. 



Reddish-clay loam to clay surface soil 6 to 15 inches, consisting mainly of 

 colluvial wash resting either upon the bedrock or upon a very thin layer of 

 stiff, red, residual clay. Soil texture and structure very similar to soil 20, 

 but soil layer is less in thickness. Smaller percentage of gravel, surface slightly 

 more compact, and not as well aerated as soil 9. 



RELATION TO YELLOW-PINE GROWTH. 



Percentage of germination and survival may not be as high as on more 

 stony and gravelly soils, but increment may be fair. The downward develop- 

 ment of roots is limited to shallow depths. 



PLOT 3b. 



The soils of this plot belong in the upper part of the Coloradan Soil Zone, to 

 the Tusayan types, and in geologic classification to the basalt group. The mineral 

 bases of the soil divisions of the plots are from the same rock source and 

 probably essentially the same in chemical character and also the same in 

 physical character of the soil profile as in Plot 3a. There is a slightly larger 

 proportional area of extremely stony soils, 12 and 6, and a somewhat smaller 

 area of nearly stone-free soils. 



Table 10. — Seedling soil survey. 



And=Atidropogon scoparius, Ann=Annuals, B\=BJepharoneurori tricholepls, C=Ceano- 

 thus fendleri, Y.v=Erigeron divergens. F=Festuca arizomca, LiOt=Lotm wrightii, 

 liup=Isupinus hillii, ll=Muhlenbergia montana, PeLn=Panicnm sp., Sit=Sitanion 

 molle and 8. brevifolium., Yic=Vieia americana. 



1. Sample plot 3a (August-September, 1920). 



PlC-t. 1 - 



Vegetation in order of abun- 

 dance. 



Num- 

 ber of 

 seed- 

 lings. 2 



Plot.i 



Vegetation in order of abun- 

 dance . 



Num- 

 ber Of 

 seed- 

 lings. 2 



H8 



Soil No. 12, rock outcrop: 



And, C, M, Lot 



55 

 24 

 17 



96 

 343 



K10 



K4 



0.7 acre.. 



Dl 



E 1 



E5 



0.3 acre... 



C3 



F6 



H4 



H5 



15 



0.5 acre.. 



Soil No. 9, gravelly clay— Con. 

 M, Bl, Vic, F... 



52 



H9.... 



M, And, Lot, C, F 



F,M,Bl,Lup 



9 



H 10 



And, Lot, C, Pan, M 



Total 



0.28 acre. 



Total 



96 







137 







Soil No. 20, fine clay: 



F, Lup, M, Vic 







Soil No. 24, stony clay: 



M, Lot, F 







13 



5 



29 



21 







K8 



f Seedlings 



F, M 1 mainly in 



F, Lup, Vic. j brush or old 



I road. 



Total 



) 



LI 



M, F 



6 



L8 



Lot,M,F 



? 



L9 



F,M,Vic 



J 



0.4 acre... 



Total 





68 

 170 



11 





Per acre 





37 





Soil No. 9, gravellv clay: 



F, M, Lup 



Soil No. 28, shallow clay: 





A5 



10 

 11 

 

 4 

 10 



17 



B2 



M, Bl, F, Vic. Lup 



F, Lup, Vic. . . 



1 



C5 





F, M, Bl, Sit 



12 



H 6 



M,F,B1 



F (nearly pure), M, Lup 



F (nearly pure), M, Vic 



Total 







J4 



M,Bl,Vic,F 



2 











32 





Per acre 



64 









1 All plots contain 0.1 acre, excepting H 8, which is 0.08 acre. 



* Only seedlings over 2 years old counted. Nearly all are 4 years or over. 



904°— 23 3 



