238 



DRAFT 



Erosion (pages 82 and 160): 



The authors state that: 



"A storm of equal intensity will cause at least two times the erosion on 

 agricultural lands as on managed forest lands (Sedell and Beschta, 

 1991). • 



Review of the cited document failed to substantiate this statement. Sedell and Beschta 

 (1991) cited one study by Hickin (1984) which reported that: 



"...riverbanks that are well bound by roots offer far greater resistance to 

 lateral erosion than relatively unvegetated banks of rivers of western 

 Canada. For similar hydraulic conditions and bank characteristics, a 

 river migrating through a cleared or cultivated floodplain would erode at 

 nearly twice the rate of one reworking a naturally forested floodplain." 

 (Sedell and Beschta 1991) [emphasis added]. 



The statement appears to be a misinterpretation of this study. The study by Hickin 

 (1984), as summarized by Sedell and Beschta, compares relative erosion rates between 

 floodplains with vegetation removed and naturally forested floodplains. The statement 

 from Sedell and Beschta (1991) makes no distinction between agricultural or forest 

 management vegetation removal: the study refers to "cleared or cultivated" floodplains 

 where "cleared" implies that vegetation was removed. In addition, erosion rates on 

 cleared land were compared to naturally forested floodplains: the assumption that 

 naturally forested floodplains are synonymous to "managed forest lands" is not 

 substantiated by Sedell and Beschta (1991). 



The discussion of floodplain functions presented in Sedell and Beschta (1991), 

 including studies by Hickin (1984) and Li and Shen (1973), substantiated the value of 

 floodplain habitats. These studies highlighted the need for the protection of natural 

 vegetation along floodplains to reduce erosion and sediment transport, protect the 

 natural ecological functions of these areas, and to provide necessary fish and wildlife 

 habitat. Sedell and Beschta (1991) referenced a study by Li and Shen (1973) in 

 reporting: "an exponential increase in relative sediment transport rate as cylinders were 

 removed (i.e. as trees were harvested) from floodplain forests. This relationship 

 highlighteid the need to retain trees on forested floodplains to reduce sediment transport 

 of flood waters." 



Grazing, (pages 84-85) 



The authors present no discussion of the regional nature of the problem, distinctions 

 between public and private range conditions, problems with bank stability, 

 groundwater, water quality, water temperature, etc. Literature citations are inadequate 

 considering Uie great amount of agency and academic interest in this topic. 



A-32 



