Excessive use by both deer and elk occurred on the study area, especially on the 

 straw-mulched plots, following plot installation in April 1968. This use resulted from 

 failure to recognize the study area as a major migration route and concentration area 

 for big game. Such use continued throughout much of the following summer in spite of 

 concentrated prevention efforts with various kinds of repellents. Intensive animal use 

 caused considerable trampling damage, especially on mulched plots. A gameproof fence 

 was installed around the study plots in early September 1968 to prevent further damage. 

 However, growth and mortality measurements in October showed that 40 percent of the 

 planted trees had died primarily because of trampling by big game. At this time, all 

 trees were carefully mapped to assure future identification. The following spring 

 (April 1969) 2-0 trees were replanted by the sam.e method as before (including fertiliza- 

 tion) at all open locations in the plots. This procedure again provided a complete 

 study, but the fence prevented the confounding effect o-P big game use. 



Data Collection 



Beginning in 1969, growth and mortality data were collected each year during late 

 August, following the active growth period of ponderosa pine. Because two populations 

 were sampled, it was necessary to record growth separately for all 1968- and 1969- 

 planted trees. A tree was considered dead if it exhibited no green needles at the time 

 of sampling. Height was measured from the top of the previous year's terminal bud scar 

 to the top of the present year's leader bud. Seeded-tree survival was recorded by count- 

 ing all green trees that were visible above the mulch. Seeded grass survival was 

 obtained by counting the number of live plants occurring in a 1-square -foot circular 

 plot placed at 10 equal intervals along the long axis through the center of each plot. 



Beginning in 1969, plot troughs were cleaned about May 30 of each year to 

 evaluate overwinter erosion rates. Troughs for all unmulched plots were cleaned 

 approximately once a week throughout the summer and early fall. Weekly cleaning was 

 necessitated by the higher erosion rates occurring on these plots. A recording rain 

 gage was operated on the study site throughout the summer-fall servicing period. Prior 

 to snowfall, on about October 15, all plots were cleaned again in preparation for 

 winter. 



All growth, survival, and erosion data were recorded on schedule until October 

 1972, which provided 4 years of data for growth and survival and 3-1/2 years of data 

 for erosion. 



