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logging, minimal surface disturbance) had a minimal and short term 

 effect on water quality. It is Stark's opinion that more severe treat- 

 ments (more surface disturbance) on different habitat types would show 

 higher levels of cations and ions in receiving waters. 



F. Chemical Changes 



Several characteristics of stream water chemistry may be affected by 

 si Ivi cultural activities, including: specific conductivity, pH, various 

 anion and cation concentrations, dissolved oxygen, etc. Harvesting 

 methods, fire (natural and prescribed), and use of pesticides are the 

 primary activities responsible for such chemical changes. 



Most research has dealt with the effects of clearcutting and/or burning 

 practices upon stream water chemistry (8,11,26,28,35,61). Specific 

 relationships cannot be generalized due to conflicting results, but it 

 appears that the combined effects of these practices are a primary factor 

 in such chemical changes. 



Pesticides may affect stream water chemistry when the chemical substances 

 are applied to, or drift into, stream courses. Overland flow and leaching 

 of pesticides are less significant mechanisms of transporting such applied 

 chemicals into the stream of the treatment area (20,29). 



Studies conducted in Montana include the following results: Bateridge (8) 

 noted higher specific conductivity in uncut watershed streams than in 

 clearcut watershed streams in the Bitterroot National Forest. He found 

 no relationship between clearcutting and sodium (Na) and potassium (K) 

 ion concentrations. 



