FOREST TYPES IN CENTRAL ROCKY MOUNTAINS. 125 



Table 40. — Mean soil moisture at control station as shown by samples from '' weU." 





Depth. 



Percentages of dry-soil weight. 



Mean 

 annu- 

 al. i 



Mean 

 grow- 



Year. 



Mar. 



Apr. 



May. 



June. 



July. 



Aug. 



Sept, 



Oct. 



Nov. 



Dec. 



ing 



sea- 

 son. 2 





Feet. 

 f 1 











9.13 



S.71 

 8.38 



6.84 

 8.42 

 9.41 



8.08 

 7.52 



8.77 

 9.40 

 9.82 



8.78 

 9.14 

 9.80 



8.82 

 9.10 



6.84 

 7.62 

 8.94 



7.91 

 8. 72 

 9.86 



6.34 

 7.65 

 8.32 

 5.29 

 7.21 

 7.54 

 7.39 



7.34 



8.56 



8.00 

 8.68 

 9.28 



6.33 

 7.32 

 8. 55 

 2.78 

 6.09 

 6.87 

 7.15 



7.16 

 9.15 



10.00 



7.04 

 8.31 

 8.16 



4.82 



7.01 

 8.16 



:. 35 

 8.65 



9. 11 



7.90 

 8.90 

 9.82 



7.35 

 7.99 



9. 12 

 5.50 

 6.98 

 7. 52 

 8.26 



4.52 

 7.54 

 8.28 

 9. 35 

 5.50 

 7.60 

 8.39 

 9.20 



8.65 



1914 



{ I 

 1 j 



i » 



1 s - 



1 



1 2 



I 3 



f 8 























9.08 



1915 



"(if 

 4.24 

 6.19 

 6.06 



(3) 

 9.01 

 10. 78 

 11.29 



7.88 

 8.14 

 9.84 

 (3) 

 7.96 

 8.78 

 9.38 



8.10 

 s.n4 

 10.11 



7.34 

 9.10 

 10.06 

 9.49 

 8.48 

 8.75 

 9.75 

 (2) 

 5.54 

 7.40 

 8.16 

 9.35 

 9.49 

 8.29 

 8.80 

 9.93 



7.50 

 8.31 

 10.67 



6.68 

 7.14 

 8.50 

 6.05 

 7.24 

 8.05 

 9.82 

 (3) 

 4.22 

 8.18 

 9.00 

 9.77 

 6.05 

 7.37 

 8.18 

 10.24 



8.63 



1916 



9.95 



7.71 

 7.89 





B.48 10.09 



8.95 



1917 



5.48 

 6.14 



7.05 

 7.93 

 (1) 

 4.26 

 6.94 

 7.83 

 9.14 

 5.48 

 7.37 

 8.06 

 8.57 



5.78 

 6.81 

 6.69 

 7.24 

 (1) 

 4.07 



3.61 

 5.91 

 6.44 



7.42 







5.72 

 6.78 





/.29 

 8.24 



4.18 





i 







7.62 











7.58 



1918 



I I 



f S. 































9.14 

 5.78 





9.35 







5.29 



2.78 

 7.14 

 7.98 



3.61 

 6.70 





5.72 



1914-1915 



1 1 8.48 



1 2 i : 9.78 



8. 12 / . 4\L 



8. 41 7. 96 



7.59 



1917 



'•9- 



8. 19 





I 3 





1U. 6i 



8.95 



8. 16 



8.33 



8.53 







9.20 



1 Omit December, 1914, and March, 1916, in computing yearly averages. 



3 The values lor June, Julv, and August are added to one-third of the September value and the sum 

 divided by 10/3. 



(1) The moisture at 1, 2, or 3 feet is remarkably uniform in differ- 

 ent years if the growing-season means be considered. This may be 

 due m part to the lack of tree growth near the "well " and the inability 

 of grasses and herbs to reach the deeper moisture. 



(2) The moisture is less during July and late summer than in the 

 spring and early summer, but is well maintained by precipitation 

 after July. 



(3) The year 1917 was the driest of record, the precipitation and 

 especially that for the growing season being below normal. 



(4) The mean figures for the soil well, for depths of 1 and 2 feet, 

 when reduced to terms of natiye soil by use of the moisture-equivalent 

 ratios, are of lower value than the actual figures for natiye soil ob- 

 tained during 1910-11. As the early sampling of the natiye soil 

 covered a considerable area, and as the soil is by no means uniform 

 over large areas, the lack of correlation may mean nothing more than 

 a difference in the conditions surrounding the measurements during 

 the two phases of the study. 



Comparative moisture in wells, all types. — In Table 41 is given a 

 summary of the well-moisture data for all stations in the study where 

 data have been obtained. For all local stations except F-12, F-14.- 

 and F-15, the data are for 1914, 1915, and 1917, beginning with July, 

 1914. For Monument the period is 1915 to 1918, inclusive. For 

 Foxpark it is August, 1916, to August, 1918. For Wagon Wheel 

 Gap it is (Al and A2), August, 1913, to August, 1918; (D) August, 

 1913, to October, 1917; and (F) July, 1915, to October, 1917/ As 

 the unusually dry year 1917 is included in each average, it is not 

 thought the variations in period will introduce any serious discrep- 

 ancy. 



