Gray, Donald H., and Walter F. Megahan. 

 1981. Forest vegetation removal and slope stability in the Idaho 

 batholith. USDA For. Serv. Res. Pap. INT-271 ,23p. Intermt. For. 

 and Range Exp. Stn., Ogden, Utah 84401. 



Results of field studies and supporting theoretical analyses show 

 that forest vegetation often provides a significant margin of safety to 

 the stability of slopes in the Idaho batholith. Woody vegetation contrib- 

 utes to the stability of these slopes by root reinforcement, by soil 

 moisture depletion from interception and transpiration, by regulation 

 of snow accumulation and melting, and by soil arching restraint be- 

 tween tree stems. Removal of vegetation by logging or fire can in- 

 crease landslide risks at many locations. 



KEYWORDS: slope stability, timber harvesting, landslides, tree 

 roots, soil water piezometry, soil arching, root reinforcement, granitic 

 slopes, Idaho batholith, mass erosion. 



Gray, Donald H., and Walter F. Megahan. 

 1981. Forest vegetation removal and slope stability in the Idaho 

 batholith. USDA For. Serv. Res. Pap. INT-271 ,23p. Intermt. For. 

 and Range Exp. Stn., Ogden, Utah 84401. 



Results of field studies and supporting theoretical analyses show 

 that forest vegetation often provides a significantmarginof safety to 

 the stability of slopes in the Idaho batholith. Woody vegetation contrib- 

 utes to the stability of these slopes by root reinforcement, by soil 

 moisture depletion from interception and transpiration, by regulation 

 of snow accumulation and melting, and by soil arching restraint be- 

 tween tree stems. Removal of vegetation by logging or fire can in- 

 crease landslide risks at many locations. 



KEYWORDS: slope stability, timber harvesting, landslides, tree 

 roots, soil water piezometry, soil arching, root reinforcement, granitic 

 slopes, Idaho batholith, mass erosion. 



