246 Forestry Quarterly. 



melting commences earlier and progresses more rapidly in the 

 forest than in the open treeless areas. This is due to difference in 

 radiation. Records taken in both situations show a much higher 

 average temperature in the forest, due to the fact that the night 

 temperatures are from 5 to 15 degrees warmer than in the adjacent 

 parks. Early in March it was noted that the soil beneath the snow 

 in the forest generally contained no frost and consisted of soft 

 mud. The origin of the soil is from decomposing "malpais," a 

 basaltic lava bed. At this time, however, a thick ice layer had 

 formed beneath the snow in the open park and was constantly 

 thickening, due to the low daily minimum temperatures. By April 

 1, the ice layer had reached a thickness of 3 to 6 inches, and it is 

 safe to say that during the month of March a relatively small 

 amount of water from the surface melting reached the soil 

 throughout the park. 



On March 17, the average depth of snow in the forest was 11.5 

 inches, and of snow and ice in the park 19.5 inches, with water 

 equivalents of 5.2 and 9.4 inches, respectively. The figures are 

 significant, when it is recalled that the measurements show con- 

 siderably less snowfall in the park than in the forest. The dis- 

 proportion of the ratio caused by the high water content in the 

 park will be noted. 



The distribution of snow was uniform in the smooth, open park, 

 while in the forest the ground surface was exposed in many places 

 and snow banks from 2 to 4 feet deep occurred in the natural 

 openings and lanes between tree groups. The depth for the 

 forest was obtained by averaging measurements taken at ten snow 

 stations spaced about 50 feet apart on a due north and south line. 

 A similar line of stations was established and used in obtaining the 

 park measurements. 



The surface run-off in the two situations is interesting from the 

 standpoint of water conservation. By April 1, bodies of water 

 overlying the ice sheet had collected in the depressions in the 

 park, and a good-sized stream was flowing at the outlet. No per- 

 ceptible surface run-off from the forest (over the locality under 

 consideration) occurred during March. The days of April 1, 2 

 and 3 were unusually warm and quiet, and resulted in the only 

 run-off from the forest during the entire spring. The amount 

 was insignificant compared to the total water content of the snow 

 mass. It is well to state, incidentally, that the writer made dailv 



