DATA 



PROCEDURE 



The data studied are a subsample of trees used by Brown 

 (1978) in estimating crown weights. Trees deleted from the 

 original data set were those lacking measurements for crown 

 width or foliage weight. Refer to Brown (1978) for a more 

 complete description and listing of the data. 



Measurements from dominant and codominant trees were 

 studied for the following 1 1 species (abbreviations are used in 

 following tables and figures): 



DF Douglas-fir 



ES Engelmann spruce 



GF Grand fir 



LP Lodgepole pine 



PP Ponderosa pine 



AF Subalpine fir 



WH Western hemlock 



WL Western larch 



WC Western redcedar 



WP Western white pine 



BP Whitebark pine 



Pseudotsuga menziesii (Mirb.) 



Franco 

 Picea engelmannii Parry 

 Abies grandis (Dougi.) Lindl. 

 Pinus contorta Dougl. 

 Pinus ponderosa Laws. 

 Abies lasiocarpa (Hook.) Nutt. 

 Tsuga lieterophylla (Raf.) Sarg. 

 Larix occidentalis Nutt. 

 Tliuja plicata Donn 

 Pinus monticola Dougl. 

 Pinus albicaulis Engelm. 



The models were developed by means of a regression 

 screening method. First, the relationships between the two 

 dependent variables of crown width and foliage weight, and 

 stand and tree characteristics were studied by screening for the 

 best combinations of the independent variables and their log- 

 arithmic transformations. Variable screening and coefficient 

 estimation were done in a multiple linear regression computer 

 program, REX (Grosenbaugh 1967). The following relation- 

 ships between the dependent and independent variables were 

 examined: 



Y = f(D, H. CL. CR, A. TPA. BA. OREL. SP. SI) 



InV = f(lna (InD)^ InH, InCL, InCfl, \nA, \nTPA, 

 \nBA, \dDREL SP. SI) 



In addition, trees of intermediate and suppressed crown classes 

 were available only for western redcedar (WC-INT), ponderosa 

 pine (PP-INT), grand fir (GF-INT), and Douglas-fir (DF-INT). 

 Tables 1 and 2 show the distribution of data used in developing 

 the models. 



Table 1. — Distribution of sample trees by species and crown class used in 

 estimating crown width 



Range of Measurements 



Number 

 of trees 



<3.5 3=3.5 Crown Stand 



Species^ inches d.b.h. d.b.h. Height length basal area 



Inches 



BP 



12 



7 



- 



10.6 



WP 



17 



8 



- 



24.7 



WC 



14 



14 



- 



26.6 



WC-INT 



11 



11 



- 



10.6 



WL 



15 



9 



- 



21.8 



WH 



16 



12 



- 



21.4 



AF 



15 



10 



- 



12.7 



PP 



15 



20 



- 



34.0 



PP-INT 



12 



9 



- 



12.1 



LP 



12 



7 



- 



15.6 



GF 



16 



13 



- 



20.4 



GF-INT 



13 



9 



- 



11.8 



ES 



14 



8 



- 



23.2 



DF 



16 



13 



- 



33.9 



DF-INT 



12 



10 



- 



11.2 



Total 



210 



160 







■Feet Feef/acre 



3 - 



44 



2 - 



36 



1 



- 181 



3 - 



126 



3 - 



88 



1 



- 299 



2 - 



127 



2 - 



98 



1 



- 300 



4 - 



64 



2 - 



42 



45 



- 335 



3 - 



129 



3 - 



75 



1 



- 271 



4 - 



126 



3 - 



111 



1 



- 320 



3 - 



93 



2 - 



70 



1 



- 260 



2 - 



144 



2 - 



89 



1 



- 325 



4 - 



70 



1 - 



44 



22 



- 280 



2 - 



84 



1 - 



60 



1 



- 271 



3 - 



137 



3 - 



108 



1 



- 432 



4 - 



72 



2 - 



60 



39 



- 296 



2 - 



128 



2 - 



105 



1 



- 240 



4 - 



143 



4 - 



86 



2 



- 238 



4 - 



83 



1 - 



47 



36 



- 360 



'See text page 2 for species list. 



2 



