Additionally, duplicate readings were taken of soil temperatures each week at 

 depths of 20 cm. (8 inches) , 50 cm. (20 inches) , and 100 cm. (39 inches) . These tem- 

 peratures were measured by thermistors within Colman fiberglass soil-moisture units 

 permanently installed at the three depths. The thermistors were usually read between 

 11:00 a.m. and 2:00 p.m. each Monday. 



Soil moisture readings in duplicate were also obtained at weekly intervals at the 

 three already designated depths. Soil moisture was determined from the amount of 

 electrical resistance within Colman fiberglass soil-moisture units buried in undisturbed 

 soil beneath existing vegetation. Laboratory calibration of the Colman units in undis- 

 turbed soil cores, taken from each level of unit placement in the field permitted 

 conversion of electrical resistance to approximate percent moisture. 



Each week, precipitation totals at all stations were recorded from unshielded 

 standard rain gage cans. A protective film of oil effectively curtailed evaporation. 

 These records were used to compare differences in precipitation between exposures. 



Recording precipitation gages measured periodicity, intensity, and duration, as 

 well as total fall at stations on the southwest exposure at both elevations. These 

 gages, the weighing type (Belfort, Model 5-780), traced a continuous 7-day record. 

 Metal deflectors shielded both from wind currents. 



Solar radiation was measured by bimetallic actinographs (Kahlsico, Model SO-28) on 

 the southwest exposure at both elevations. The combined measures, diffuse sky radiation 

 and direct solar radiation, are expressed as both maximum intensity and as total energy 

 received per day. 



The amount of wind each station received was measured by totalizing, 3-cup anemom- 

 eters mounted 6 feet above the ground. These were read weekly. Data are expressed as 

 average miles per hour per week. 



Weather records were collected at all stations during five growing seasons 

 (1964 through 1968). Those for the stations at the 7, 100- foot elevation were recorded 

 from May 1 to November 1. Usually, the winter snowpack has melted from the southwest 

 exposures at this elevation by late April and from the northeast exposures by early May. 

 Although occasional snowstorms are not unusual in May, June, September, and October, the 

 winter snowpack generally does not begin to form until sometime in November. 



Weather records for the stations at the 8,200-foot elevation were begun as soon as 

 the areas were reasonably accessible, anytime during the first 2 weeks of June. The 

 winter snowpack generally had melted from the southwest exposures at this elevation by 

 early June and from the northeast exposures by about mid-June. Although snowstorms can 

 occur at this elevation any month of the year, the winter snowpack usually does not 

 begin to form until sometime in October. Thus, the weather records for the two upper 

 stations covered approximately 3-1/2 months each year and those for the lower stations 

 about 6 months of each study year. 



The tabular and graphic data published here are for one station only, that on the 

 southwest exposure at the 7,100-foot elevation. Differences between exposures and 

 between elevations are discussed in the text. 



Data from U.S. Weather Bureau stations permitted comparisons of monthly means of 

 daily maximums, means of daily minimums , and the highest and lowest temperatures reached 

 during the month. Precipitation comparisons are of total amounts received during monthly 

 periods. Data for all comparisons cover the growing seasons from 1964 through 1968. 



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