48 Forest Club Annual 



native timber had an important part in the development of west- 

 ern Nebraska. 



With the knowledge of the importance of timber in the de- 

 velopment and progress of a community, it was deemed advisable 

 to commence experiments at the Experiment Substation at North 

 Platte, in order to determine, if possible, the species best suited 

 to western Nebraska, the relation of soil and climate to the 

 selection of species and the best silvicultural methods to be 

 employed. The original plans were to plant 32,959 trees com- 

 mencing in the spring of 1907 and finishing in the spring of 

 1910. These plans were somewhat changed but the entire twenty- 

 five acres devoted to the experiments were planted. 



The climate of this region is characterized by rather severe 

 winters and warm summers, with sudden and extreme changes 

 of temperature. The maximum temperature for thirty-four 

 years, 1875 to 1908, was 107 F. and the minimum temperature 

 was 35 F. The average date of late killing frosts in spring 

 was May 1 and the average date of the first killing frosts in 

 autumn was September 29. The mean annual relative humidity 

 for twenty-one years, 1888 to 1908, was 71.0 per cent. The 

 average annual rainfall from 1875 to 1908 was 18.72 inches. The 

 average for the months of April, May, June, July and August was 

 13.55 inches or 72.0 per cent of the total for the year. The 

 average wind velocity from 1875 to 1908 was 10.0 miles per 

 hour. The average velocity for April, May, June, July and 

 August was 10.4 miles per hour. The high wind velocity to- 

 gether with the high temperatures of summer causes excessive 

 evaporation from the soil, which greatly decreases the amount of 

 moisture available for plant growth and at the same time in- 

 creases the amount actually needed by the trees. 



The absolute elevation of North Platte is 2,825 feet. The 

 relative altitude of the "bench land" is approximately seventy- 

 five feet while the "table land" is one hundred fifty to two hun- 

 dred feet above the Platte River. The "bench land" is located 

 on the second bottom of the Platte River Valley and extends 

 to the base of a range of hills to the south. The "table land" 

 is the highest land on the Experiment Station Farm and 

 is approximately one hundred twenty-five feet higher than 

 the "bench land." This area is cut by many canyons which lead 

 in all directions giving the region a very rough surface. The 

 sides of the canyons are usually steep while the bottoms are 

 generally narrow. There is a large acreage of this kind of 



