Of special interest is the amount of throughfall-drip percolate that occurred at 

 station 47 on the south aspect. Water contributed by throughfall and drip at this 

 station is large in comparison with stations on the north aspect (table 3) . The con- 

 tribution for the 2 months exceeded that of station 40 and station 42 by 1.71 inches 

 and 1.31 inches, respectively. 



Snowmelt as defined in this study did not occur in every month of the experiment. 

 For instance, during November 1967 melt did not occur because precipitation fell as 

 rain early in the month and drained promptly from the lysimeter pan to catchment tank. 

 By the end of November, snow fell and remained frozen. 



Melt rates from February 24 through March 2, 1968, were abnormally high at the 

 forest station. Prior to February 24, a storm precipitated snow on the 17th; by the 

 next day it turned to rain, continuing to produce rain intermittently through February 

 23. After clearing (unlike poststorm trends in other winters) , the weather remained 

 very mild and clear until after March 2. Snowmelt percolate in the forest for the 

 8 consecutive days was 70 percent greater than in the small opening (table 4) . Through- 

 out the period of clear weather, the canopies were bare of snow; therefore, they did not 

 contribute drip to the snowpack. 



From the ablation season (March 26, 1969, mtil March 31 — all clear days), rates 

 of melt were consistently greater in the forest (stations 40 and 42) than in the small 

 openings (stations 39 and 45) . There were other isolated periods during winter when 

 rates of melt in the forest were greater (tables 2 and 4) . However, the relationship 

 was not consistent; melt in times of cloudy weather generally proved to be slightly 

 greater in the small openings. 



Differential release of water from snoypac??c. --Differential release of outflow is 

 evident between the forest and small openings and between north and south aspects. 

 Mention has already been made of how drip and snowmelt apparently account for most of 

 the variation. A plotting of individual monthly differences as well as the algebraic 

 sum of monthly differences shows the overwhelming effect of the forest in speeding up 

 the release of water (figs. 6 and 7). With exception of four out of six comparisons in 

 November, all remaining comparisons for December, January, February, and March show a 

 difference in favor of the forest condition. Numerically the forest differences for 

 the season range from 1,35 inches in the lowest year to 5.45 inches in the highest year 

 (table 3). 



Topographic exposure apparently has an additional effect on seasonal outflow. 

 Based on the months of November, December, and January, outflow from all stations on the 

 south aspect averaged 5.12 inches compared with 3.88 inches on the north aspect. This 

 comparison pertains only to the 1 year (1969-1970) when data were taken on the south 

 aspect. 



12 



