The average number of subplot saplings 

 found in 1992-95 California plots, four indi- 

 viduals, was almost the same as the average 

 for the Pilot Study plots, three individuals. 

 Pilot Study sites, however, had one-third more 

 pole (18 vs. 12 individuals) and about twice as 

 many sawtimber trees (11 vs. 6 individuals). 

 More plot and unit-area pole and sawtimber 

 trees in Oregon and Washington (table 5-3) 

 probably reflect older stands that have more 

 overs tory trees. Washington plots had char- 

 acteristics of younger stands compared to Or- 

 egon plots: twice the number of saplings and 

 about 1.5 times as many poles. 



Table 5-3 — Plot structure data for the Northwest 

 Pilot Study 



Data 



in managed and unmanaged stands (table 5- 

 4). Higher values in Oregon reflect those for 

 older stands. In the California 1992-95 data, 

 live basal area averaged about 96 square feet/ 

 acre, including pole and sawtimber trees for 

 all species. 



Table 5-4 — Basal areas typically found for different 

 species and age classes in Northwest forests 



Species 



(age range in yr) 



Basal area ranges 

 (ftVacre) 



Douglas-fir (0-750) 

 Western hemlock (100-500+) 

 Western redcedar ( 1 00-500+) 

 Red alder (0-1 00) 

 Bigleaf maple (100-400) 



20-180+ 

 40-180 



0-80+ 



0-20 



0-20 



Oregon 



Washington 



Number of trees per acre 



Saplings 

 Poles 



Sawtimber 

 Totals 



78 

 45 

 33 



159 

 63 

 34 



156 



256 



Basal Area 



Basal area is a measure of the total cross- 

 sectional area of tree boles at breast height 

 in square feet. The higher the value, 

 the more cross-sectional area is oc- 

 cupied by bole wood. How the bole 

 wood is partitioned, however, deter- 

 mines economic value as well as in- 

 fluences habitat diversity. If large 

 total basal area is spread over 

 many very small stems, they are 

 probably not merchantable for 

 posts, poles, or pulp. Many 

 small old stems produce 

 densely shaded stands that do 

 not usually allow growth of 

 thick understory vegetation. 



The average Live basal area 

 combined for poles and saw- 

 timber was 204 square 

 feet/acre in Oregon, and 



CROWN RATINGS 



Many factors affect seedling and tree growth: 

 internal factors are vigor and age of the plant 

 and external ones are light, water, and nutri- 

 ents. Light reaching a tree or seedling is in- 

 fluenced by the individual's position in the 

 canopy; relative position to neighbors; and the 

 shape, size, and condition of the crown. Thus, 

 crown evaluations indicate whole tree condi- 



Vigor Class I 



>l/3 total height 

 in foliage; 



<5% dieback in crown; 



>80% of foliage is 

 normal 



Vigor Class 2 



does not meet Class I 

 or Class 3; 



any crown length; 



may or may not have 

 dieback; 



21 to 79% foliage is 

 normal 



Crown dieback 



Missing fotiage 



Vigor Class 3 



any crown length; 



I to 20% normal 

 foliage or 



sum of dieback + 

 abnormal foliage >80% 



154 square feet/acre in 

 Washington. These val- 

 ues are well within 

 ranges typically found 



Total height 4.5 ft ( 1 .4 meters) 

 Crown length 1 .9 ft (0.6 meters) 

 Live crown ratio 42% 



4.5 ft (1.4 meters) 

 1 .4 ft (0.4 meters) 

 31% 



4.3 ft ( 1 .3 meters) 

 0.6 ft (0.2 meters) 

 14% 



Sapling crown vigor classes. 



Monitoring — 69 



