Table 7 describes the relationship between the 

 number of green trees counted on the photo 

 subplots and the number counted when these 

 plots were measured on the ground. The photo 

 count of green trees was 16 percent below the 

 ground count. Grand fir and Douglas-fir were the 

 most common species on the photographs. The 

 photo count of grand fir was 88 percent of the 

 ground count. The photo count of Douglas-fir was 

 82 percent of the ground count. The otherspecies 

 were too poorly represented in the sample to 

 make inferences about the accuracy of the photo 

 counts. 



The second-year photo interpretation made use 

 of both the 1 971 and 1 972 photography. All 1 -year 

 and 2-year mortality trees were identified by 

 species on the 1:3200 scale, 1972 photography. 

 Each tree that also appeared on the 1 971 photog- 

 raphy was located and examined on the 1:1600 

 true color photography obtained in 1971. 



Of the 1 -year mortality trees, 89.4 percent were 

 properly identified on the 1:3200 scale photog- 

 raphy. All trees identified as 1 -year mortality trees 

 on the 1 :3200 scale, 1 972 photography were alive 

 in 1971. A small number of trees identified as 2- 

 year mortality on the 1 972 photography were alive 

 in 1971. 



Table 7.— Species identification of green trees on 1:1600 scale photography 



Species 



Flight Source Grand Douglas- White Western Western Western Ponderosa Lodgepole 

 line of data fir fir pine hemlock larch redcedar pine pine Total 



Photo count 48 43 23 6 5 6 4 — 135 



Ground count 57 46 30 8 5 8 5 — 159 



Photo count 34 95 1 1 1 — — 2 134 



Ground count 44 113 1 1 1 — 1 2 163 



Photo count 52 69 — 1 11 — — 3 136 



Ground count 52 92 — 1 15 — — 3 163 



TOTAL 



Photo count 134 207 24 8 1 7 6 4 5 405 



Ground count 153 251 31 10 21 8 6 5 485 



7 



