CONTENTS 



Page 



INTRODUCTION 1 



SETTING 2 



PROCEDURE 3 



PLANT DEVELOPMENT 5 



HERBAGE PRODUCTION 14 



MANAGEMENT IMPLICATIONS 19 



LITERATURE CITED 20 



ABSTRACT 



Plant development and herbage yields were observed for 5 consecutive years on natural 

 mountain grasslands in southwestern Montana. Data were obtained from southwest and north- 

 east exposures at elevations of 7, 100 and 8,200 ft. Differences in development and production 

 are compared between years, exposures, elevations, and species. 



Beginning of growth in any 1 year differed between species and spread over about 

 3 weeks at the lower elevation and 2 weeks at the upper elevation. Lomatium was one of the 

 earliest species to begin growth and Lupinus among the latest. Maximum difference in be- 

 ginning of growth over the 5 years varied from as much as 32 days for Lomatium to as few 

 as 13 days for Lupinus : the average for all species was 20 days. Again, depending upon the 

 particular species, growth usually began 3 to 12 days later on northeast exposures than on 

 southwest exposures and an average delay of about 1 week was observed for all species. 

 Start of growth was usually 19 to 37 days later at the 8,200-ft. elevation than at 7, 100 ft. and 

 averaged 27 days later for all species. 



The onset of flowering of different species in any 1 year was spread over about 10 weeks 

 at the 7,100-ft. elevation and 7 weeks at the 8,200-ft. elevation. The greatest difference 



