

FOREST TYPES IN CENTRAL ROCKY MOUNTAINS. 13 



same original conditions, now changed by disturbance of the forest 

 cover. (See PL IV, fig. 1.) 



At this station the following equipment has been used: 



1 and 4 foot soil thermometers, in iron pipes, July 9, to December 12, 1914, 

 and March 3, 1915, to April, 1920, with the exception of March, 1916. 1-foot 

 pipe replaced by wooden tube April 26, 1918. 



Soil well in use from July 13, 1914, during open seasons, to end of 1917, weekly 

 determinations being made of moisture at 1, 2, and 3 foot depths, and during 

 1917 at the surface. 



Evaporimeter, Piche, July 7, 1914, to December 12, 1914, and June 8, 1915, 

 to October 24, 1915. Later evaporation records made at Station 7 



F-7-8: Fremont north slope Douglas fir, clear-cut. — This station 

 lies midway between Stations 7 and 8 in a clear-cut plot. At this 

 elevation, which is only 16 feet higher than Station 7, the Douglas 

 fir in the original stand was clearly predominant, while at Station 8 

 it had practically no competition. This location was selected in the 

 center of the clear-cut plot to represent atmospheric conditions for 

 the plot as a whole. 



The equipment has been as follows, all placed about 1 foot above 

 the ground: 



Maximum and minimum thermometers, on shielded board, September, 1915, 

 to September, 19 IS, excepting March, 19 1G. 



Air thermograph, on shielded board. 

 Psychrometer (beginning May 1, 1910). 

 Anemometer, with register. 

 Evaporimeter, Type 2, 1910; Type 4, 



1917. 



Evaporimeter, Type 4, January 1, 1918, to April, 1920. 



Sunshine recorder, electric thermometric, with register, during first third of 

 each month from July to October, 1917. 



8-inch rain gage, April 0, 1910, to December 31, 1917. 



F-8: Fremont north slope Douglas fir. — Elevation, 9,137 feet; 

 aspect, N. 22° E.; slope, 26 per cent. The conditions surrounding 

 this station are very similar to those at Station 7, except that the 

 slope to the north is 8 per cent less steep, and Station 8 is at a higher 

 position on the slope. This difference was sufficient to introduce a 

 marked difference in the original forests at the two stations, the 

 forest at Station 8 being almost pure fir, while at Station 7 Engel- 

 mann spruce comprised half the stand. The possible insolation of 

 the soil at Station 8 is probably made greater by the nearness of 

 the station to the top of the ridge, with reduced opportunity to 

 secure seepage water and transported soil. The evaporation records 

 of 1914 also indicate that the higher position gives Station 8 some- 

 what greater exposure to drying influences. 



The equipment of this station has been identical with that of 

 Station 7, except that the Piche evaporimeters were used here only 

 during 1914. The conditions recorded here may properly be averaged 

 with those at Station 7 to obtain data representing the clear-cut 

 area as a whole. 



F-9: Fremont north slope Douglas fir, uncut. — Elevation, 9,099 

 feet; asnect, N. 10° E.; slope, 33 per cent. It is seen that this 

 location is practically identical with that of Station 7, except that 

 the slope does not bear quite so much away from the north and 

 is protected by a virgin forest cover, while Stations 7 and 8 are in 

 an artificial opening of the same stand. (See PL IV, fig. 1.) 



April 1, 1910, to December 31, 

 1917. Rotated with Stations 

 14 and 15, this station being 

 reached the first decade of each 

 month. 



