Figure 4. — Feroent of 

 available gr cuing 

 space covered by 

 grasSj shrubs^ and 

 herbs. Available 

 growing space in- 

 cludes all portions 

 of the unit except 

 padj parking spur, 

 trails J rocks 3 trees ^ 

 and tree stumps. 

 (All units received 

 grass seed. ) 



50 



40 



30 



cc 



20 



10 



Water and 

 fertilizer 



Water 



Fertilizer 



Control 



'67 '68 '69 '67 



'68 



'69 '67 '68 

 YEAR 



'69 '67 '68 '69 



CONCLUSIONS 



It is undoubtedly premature to attempt to project the time required to achieve a 

 satisfactory level of ground cover with the various treatments. Data for two seasons 

 of growth are not conclusive. Nevertheless, the dramatic results achieved with water, 

 fertilizer, and seed strongly suggest that a satisfactory level of ground cover can be 

 expected at the end of the third full growing season. Rates of change observed so far 

 indicate that, without water, it could take 20 years or longer to revegetate a badly 

 worn campground, as shown in the following tabulation: 



Treatment 

 Seed only 



Fertilizer and seed 



Water and seed 



Water, fertilizer, and seed 



Years required to produce 

 70-percent cover 



Never 



At least 20 

 At least 10 

 At least 3 



These time estimates assume that: (1) 70-percent ground cover is adequate and 

 realistic; and (2) the vegetation will continue to improve at the same rate as was 

 observed during the 2-year study period. 



8 



