UNITED STATES DEPARTMENT OF AGRICULTURE 



sZ&%-ru 



BULLETIN No. 675 



Contribution from the Forest Service 

 HENRY S. GRAVES, Forester 



Washington, D. C. 



June 25, I »I 8 



RANGE PRESERVATION AND ITS RELATION TO 



EROSION CONTROL ON WESTERN 

 GRAZING LANDS. 



By Aethub W. Sampson, Plant Ecologist, and Leon H. Weyl, Grazing 



Examiner. 



CONTENTS. 



Page. 

 Purpose of the study 1 



Damage caused by erosion 2 



Factors determining the amount of erratic 

 run-off and erosion 6 



Relation of erosion and soil depletion to vege- 

 tative growth : 18 



Relation of erosion and soil depletion to 

 revegetation 22 



Influence of grazing on erosion and stream 

 flow 24 



Page. 



Preventive and remedial measures 27 



Maintenance or restoration of the vege- 

 tative cover 27 



Remedial measures where thorough re- 

 vegetation by ordinary means is im- 

 possible 31 



Summary of preventive and remedial 



measures ■ 34 



Conclusions 34 



PURPOSE OF THE STUDY. 



The aim of this bulletin is to show the relation between range 

 preservation and erosion and its control on grazing lands in the 

 West. It is true, perhaps, that topography, climate, and soil are the 

 primary factors in determining erosion ; but, on the lands under dis- 

 cussion, the combination of these factors with the vegetative cover 

 is such that erosion is slight where the natural conditions have not 

 been disturbed and may be made serious by any influence which 

 upsets the balance established by nature. Grazing may become such 

 a disturbing influence by changing or destroying the vegetative 

 cover. Numerous instances are on record where serious erosion was 

 unknown until the ground cover was largely destroyed. On the other 

 hand, in localities where the destroyed vegetation has been reestab- 

 lished, a few typical cases of which are pointed out in the body of the 

 report, serious erosion has been stopped. 



46360° — 18 — Bull. 675 1 



