Table 8. — Area in acres of productive forest land suitable for timber use at full 

 yields and with modified yields by availability class, East Working 

 Circle, Klamath National Forest 



Availability 

 class 



Full yields Modified yields 

 expected expected 



Total 



-Acres- 



Available now^ 

 Potentially available: 

 Stable land with timber 



grovvdng and access 



problems 

 Unstable, potentially 



usable land, no other 



problems 

 Unstable land and timber 



grovidng and access 



problems 



335,190 



13,826 



349,016 



12,719 



8,715 



1,123 



706 



12,719 



9,421 



1,123 



Total 



357,747 



14,532 



372,279 



and volume. Field samples were mechanically 

 spaced 1.7 miles apart. In the inventory of the 

 Gifford Pinchot Working Circle in 1960, three 

 subplots were taken at each sample location. In 

 the 1969 inventory, the locations established in 

 1960 were revisited and a standard 10-point 

 plot was established. 



In the 1960 inventory, the total area of the 

 working circle was sampled. By contrast, in the 

 1969 inventory, the obviously noncommercial 

 forest and nonforest land were mapped. Also, a 

 recent soil map and an updated multiple use 

 map were used to further classify locations so 

 that the area of "apparent commercial forest 

 land" could be further stratified. 



Before the 1960 and 1969 inventories could 

 be compared, it was necessary to adjust the 

 1960 estimates. After 1960, a new estimate of 

 area in the Forest was made, recomputing area 

 township by township and section by section 

 where necessary. A new area weight was com- 

 puted for each location and subplot to corre- 

 spond with the corrected total area of the 

 Working Circle. Following are the earlier and 

 the current corrected area estimates for the 

 Working Circle by broad land class : 



Land class 



Earlier 

 estimate 



Commercial 1,029,477 

 Noncommercial 74,553 

 Nonforest 38,519 

 Total 1,142,549 



1969 Inventory 



Current 

 corrected 

 estimate 



1,041,252 

 75,408 

 38,960 



1,155,620 



In 1969, the total area in the Working Circle 

 was 1,161,420 acres. The difference between 

 this and the corrected 1960 estimate shown 

 above was due to land exchange and sampling 

 error. 



Of the 1,161,420 acres, 135,030 acres were 

 mapped as obviously noncommercial or non- 

 forest. The remaining 1,026,390 acres in the 

 Gifford Pinchot Working Circle plus the Sno- 

 qualmie Working Circle of 79,499 acres were 

 field sampled in this inventory utilizing 580 

 field locations. The area weight of each field 

 sample was 1,906.7052 acres. 



1,105,889 ^ 

 580 



1,906.7052 



30 



