INTRODUCTION 



Phenology--many foresters and 'botanists talk about it, but few do anything about it. 

 Perhaps it has been a function of low demand, difficulty of making meaningful measurements, 

 failure to see its application, or a host of other reasons. Unfortunately, much of the pheno- 

 logical data collected have been for specific and immediate purposes, such as range condition 

 or fire danger. Little has been published nationally or in the Northern Rockies. Although 

 some phenology information is available for the Northern Rockies, no comprehensive data for the 

 mountain forest flora have been readily available. 



The mix of forest uses, priorities, and management intensities is changing in the Northern 

 Rockies. Lands are being managed for an increasingly wider range of resources, requiring a 

 greater breadth and depth of knowledge about vegetation. As a result, the whole vegetation 

 complex is assuming more importance, regardless of the resource values being featured in 

 management . 



Not only is the management activity itself important, but in many cases, the timing of the 

 activity is important. This is not something we recently discovered. R. H. Weidman, who was 

 primarily responsible for this study, said in his USDA Forest Service Northern Rocky Mountain 

 Forest Experiment Station study plan of 1928: 



Knowledge of the phenological events of the forest are essential to a thorough 

 understanding and organization of forestry operations. It is particularly desirable 

 to know the time of leafing and pollination, the time of cone opening and seed 

 dispersal, the time that diameter and leader growth commences and ends. It is, 

 moreover, as important to know the time that seed germinates in natural locations 

 as in nurseries. To properly understand inflammability conditions in connection 

 with fire protection, it is important to know also when shrubs become succulent, 

 when the principal perennials cover the ground, and when they wither and die. 



The practical value of phenological observations has long been recognized in 

 grazing management to determine range readiness and other matters. The forest 

 pathologist and the forest entomologist have to correlate the seasonal development 

 of host plants with the behavior of the rust or insect parasite. 



Now, because of broadening management and research perspectives, demand is accelerating 

 for information concerning phenology of forest species found in the Northern Rockies. We have 

 had to search the archives in attempts to find the data. The archives we have looked to most 

 frequently are an extensive set of phenological data collected on forest lands in the Northern 

 Rockies from 1928 to 1937. 



For various reasons, these data were never published and few people are aware they even 

 exist. We feel that even though the collection period overlapped the Roaring 20 's and the Great 

 Depression, the research is just as valuable now as then. Computational techniques not avail- 

 able at the culmination of the study in 1937 now make it possible to make the data more 

 meaningful than practicably possible at that time. 



Many phenological studies in this century have attempted to relate phenological events to 

 various meteorological data. Fire-weather records, mainly temperature, were available for many 

 of the locations used for the 1928 to 1937 phenological data. Ellison^ attempted to link the 

 weather and phenology data, but his results were disappointing in that no real meaningful 

 relationships were detected. 



As a result, we decided to present what we feel are tlie strengths of the st(jdy--straight- 

 forward summaries of the data including earliest, latest, and average dates, as well as standard 

 errors (in days) for phenological events in the Northern Rockies. We attempted no further 

 analyses of weather-phenological relationships. 



^The report of Ellison's analyses is on file at the Intermountain Forest and Range Experi- 

 ment Station, Forestry Sciences Laboratory, Bozeman, Montana. 



1 



