METHODS 



Trees of dominant and codominant crown classes CSociety of American Foresters 

 1944) were studied for the following 11 species (abbreviations are used in tables and 

 figures) : 



Sample trees were selected to complement data on dominant and codominant crown 

 classes gathered by Storey and others (1955) and Fahnestock (1960) . Combining data 

 economized effort to develop prediction equations for a wide range of tree sizes. 



Trees of intermediate and suppressed crown classes were studied for ponderosa pine, 

 Douglas-fir, grand fir, and western redcedar. These four species range from shade in- 

 tolerant to tolerant. By studying them, the influence of shade tolerance and crown 

 class and their interaction on crown weight per tree could be examined. Throughout the 

 remainder of this paper, "dominants" refer to both dominant and codominant crown 

 classes and "intermediates" to both intermediate and suppressed crown classes. Most of 

 the intermediates sampled were from the intermediate rather than the suppressed crown 

 class . 



Selection of Trees 



Trees were selected, ranging from seedling size to 34 inches d.b.h. The sampling 

 was designed to include the natural variation in crown weight by selecting trees from 

 stands on poor-to-good sites and from low-to-high stand density conditions throughout 

 western Montana and northern Idaho (fig. 2) . The geographic distribution of trees is 

 shown in appendix I. Trees were randomly picked; however, they were not accepted if 

 they were (1) open-grown or "wolf" trees; (2) extremely lopsided in the crown; (3) 

 deformed excessively by disease; (4) heavily defoliated; and (5) broken topped. These 

 rules applied to data by Storey and Fahnestock except that our sites and stand densities 

 were more restricted. 



DP 



S 

 GF 

 LP 

 PP 

 AF 

 WH 



L 



C 

 WP 

 WBP 



Douglas-fir 

 Engelmann spruce 

 Grand fir 

 Lodgepole pine 

 Ponderosa pine 

 Subalpine fir 

 Western hemlock 

 Western larch 

 Western redcedar 

 Western white pine 

 Whitebark pine 



Pseudotsuga mensiesii (Mirb.) Franco 



Picea engetmanni'L Parry 



Abies grandis (Dougl.) Lindl. 



Pinus contorta Dougl. 



Pinus ponderosa Laws . 



Abies lasiooarpa (Hook.) Nutt. 



Tsuga heterophylla (Raf.) Sarg. 



Larix oocidentdlis Nutt. 



Thuja plicata Donn 



Pinus monticola Dougl. 



Pinus aVbioaulis Engelm. 



Fieldwork 



3 



