RANGE PRESERVATION AND EROSION CONTROL. 35 



greater and shows itself in decrease in carrying capacity of the 

 lands. 



3. While topography, climate, and soil are the primary factors in 

 determining erosion, the combination of these factors on the lands 

 under consideration is such that erosion is slight where the Dative 

 ground cover has not been greatly disturbed. The seriousness of 

 the erosion, therefore, is largely determined by the extent to which 

 the ground cover is maintained. 



4. Serious erosion on western range lands is due chiefly to the 

 destruction of the vegetation as a result of overgrazing and mis- 

 management of live stock. 



5. The sum of conditions favoring destructive run-off and erosion 

 is most pronounced in the fan-shaped drainage basins of the spruce- 

 fir type (on the Manti National Forest between 9,000 and 10,500 

 feet), where the ground cover is naturally rather sparse, where there 

 is a characteristic sparseness of tree growth, and where the most 

 desirable summer sheep ranges are located. 



6. To maintain an effective vegetative cover, overgrazing and too 

 early cropping of the herbage must be avoided, deferred and ro- 

 tation grazing should be applied, and stock should be properly con- 

 trolled and distributed at all times in the season. 



7. In the case of incipient erosion, only slight changes in the use of 

 the lands are generally necessary, and these changes do not neces- 

 sarily imply even a temporary financial loss. 



8. Where erosion has had full play for a number of years, the 

 reestablishment of the ground cover, even though grazing is dis- 

 continued, does not always afford adequate protection. In such in- 

 stances, which fortunately are relatively rare in this country, a 

 combination of terracing and planting or, in exceptional cases, the 

 construction of dams is justified. 



ADDITIONAL COPIES 



OF THIS PUBLICATION MAT BE PROCURED FROM 



THE SUPERINTENDENT OF DOCUMENTS 



GOVERNMENT PRINTING OFFICE 



WASHINGTON, D. C. 



AT 



10 CENTS PER COPY 

 V 



