General plan . --The survey method and type of data collected are similar 

 in general to the extensive inventory of the Tongass National Forest. 

 The Interior survey can be intensified, when cooperative assistance is 

 given, by modification of the survey method. 



Area sample . --Areas of forest land will be estimated by sampling on 

 strips of aerial photography, at a scale of 1:5,000, flown at 30-mile 

 intervals. One location per photograph will be classified. These loca- 

 tions will be marked systematically along the flight lines. Area esti- 

 mates of commercial forest land will be deteirmined for each of ten units 

 by forest types, stand-size classes, and crown density classes. Esti- 

 mates will also be obtained for nonforest and noncommercial or protection 

 forests. A statistical sample of the photo locations will be examined by 

 air to check the accuracy of classification and, where necessary, the 

 proportion of the various classes will be adjusted. Estimates of area 

 will be products of area represented by each location and number of 

 locations per class. 



Volume sample . --Volume estimates will be determined from aerial photo 

 stand volume tables. These tables are related to photo measurements of 

 stand height and density and correlated with gross volume per acre by 

 density-height classes. Estimates of defect will be computed by apply- 

 ing percentages to gross volume by species-height classes. Photo measure- 

 ments will be made on one-half -acre rectangular plots coincident with the 

 area sample. Estimates of total volume will be products of area and 

 mean-volume-per-acre by classes. A sample of the photo volume plots will 

 be field examined to provide a check on photo volume measurements. 



Inventory field sample . --Growth, species, diameter distribution and 

 mortality data will be obtained from examination of field plots located 

 at random within the various sampling strata of commercial forest land. 

 These locations will be one-half-acre rectangular plots selected from 

 the volume sample plots. 



Plans for 1958 

 Coastal Alaska 



1. Complete reports for the remaining timber management working circles 

 on the North and South Tongass National Forests: Petersburg, Sitka, 

 Ketchikan, and Yakutat. 



2. Complete forest type map at 2 inches = 1 mile for the North and South 

 Tongass National Forests. 



3. Begin woods utilization study. 



4. Begin aerial photography program for the Chugach National Forest. 



5. Begin photo interpretation of Chugach photography. 



