be clipped in 1981. At a future date, exclosure effects may need to be 

 evaluated by comparing frequency, density, and basal area measurements 

 (depending on the species involved) within and outside exclosures. 



Considerations in designing air pollution monitoring studies are described 

 elsewhere (Prodgers 1981). 



Controlled grazing of exclosures should continue as needed to control 

 excessive litter accumulation. Livestock should be put into the selected 

 exclosures for a brief period of time, the effects monitored, and the cattle 

 removed when the desired level of grazing has been attained. 



An effort should be made to gather more information on the distribution of 

 Rorippa calycina in the permit area. 



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