INTRODUCTION 



The Circle West vegetation studies, established to describe existing 

 vegetation and to monitor the long-term productivity and canopy-coverage of 

 selected plant communities in McCone County, Montana, began in 1976 at the 

 request of Dreyer Brothers, Inc. 



The Circle West Vegetation Baseline Study (Prodgers 1978) identified 

 community types for the study area through cluster analysis of 1976 vegetation 

 data. Community types were described botanical ly and associated sites were 

 characterized. Using this information, thirteen exclosures (figure 1) were 

 chosen for long-term monitoring in order to provide a data base for assessment 

 of strip mine reclamation success and possible air pollution effects. 

 Productivity and canopy-coverage were measured at these exclosures from 1977 to 

 1979 (Montana Department of Natural Resources and Conservation 1979a, b). The 

 data reported here represent the results of the third annual monitoring study 

 conducted in August 1980. These results are compared with those of the 1977 

 baseline study, and the 1978 and 1979 monitoring studies. 



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