Effects of Forest Upon Snow Waters. 247 



trips between the two measuring stations, which afforded an 

 opportunity for noting the conditions. 



A spell of warm weather occurred during the first half of 

 April. By April 8, the depth had decreased to an average of 8.5 

 inches in the park (6.5 inches of snow and 2.0 inches of ice), and 

 3.8 inches in the forest. In the following five days, of high tem- 

 perature and strong southwest winds, practically all of this snow 

 and ice disappeared from the park, accompanied, it is needless to 

 state, by an excessive run-off which continued for a few days 

 after the period. On April 15, no snow existed in the park, while 

 throughout the forest there remained considerable snow dis- 

 tributed in banks and ridges over the north slopes and level sur- 

 faces as well. Photographs shown on the frontispiece give a good 

 idea of the appearance on this date of the measuring stations in 

 the park and forest, and the remaining snow, banks of snow, on 

 northerly slopes in the mature timber. In the timber throughout 

 this region there remained on April 25 a considerable quantity of 

 snow in sheltered situations favorable for late melting, while the 

 last trace of snow had disappeared from the park by April 12. 



The progress of accumulation and later melting of snow in the 

 two comparative situations may be summarised as follows : 



(1.) The total snowfall in the forest is somewhat more than 

 over the open parks, due chiefly to accelerated wind velocity over 

 the parks, resulting in a lighter deposition of snow, a case similar 

 to the deposition of silt in stream courses. 



(2.) Due to protection afforded by the forest cover against ex- 

 tremes of cold resulting in a higher average temperature, the pro- 

 cess of melting during the spring commences considerably earlier 

 in the forest than in the adjacent open park. 



(3.) The low minimum daily temperatures in the park account 

 for the formation of a thick layer of ice at the base of the snow 

 during the early spring. This in turn serves to retain the moisture 

 above the soil. 



(4.) During the month of March, the park remained almost 

 entirely covered with a deep and quite uniform layer of snow and 

 ice, while in the forest the snow cover was much broken along 

 rock ledges and banked high in the natural tree avenues, and the 

 total amount of snow and water content above the soil surface 

 was decidedly less per unit of area in the forest than in the park. 

 16 



