TIMBER GROWING AND LOGGING PRACTICE IN CALIFORNIA 49 
THE REAL COST OF SEED TREES 
Becent studies on the cost of log making, yarding, and manufac- 
ture of trees of different sizes have been made by Girard in Montana-, 
and Bruce, Berry, Price, and Show in California. Bruce's conclu- 
sions (5) are that " it costs three times as much per thousand feet 
board measure to make logs from 18-inch as from 48-inch trees, 
and below that diameter the costs undoubtedly rise rapidly with 
each further decrease in size." The writer's conclusion, already 
stated in another connection (IS), is that " even for 20-inch trees the 
cost per thousand feet of sawing is over twice what it is for large 
mature trees, and for the smaller trees the discrepancy is still 
greater." 
The relative cost of yarding trees of different sizes has been studied 
by Price in connection w^ith a comparative study of ground and 
high lead yarding, from data obtained on an efficient operation in 
the mixed conifer type. Trees w^ere yarded as a unit to as large a 
size as possible. The data are summarized in Table 4. 
Table 4. — Effect of size of tree on cost of yarding 
Diameter 
Output 
Diameter 
Output 
Diameter 
Output 
breast 
per 
breast 
per 
breast 
per 
bigh 
turni 
higb 
turni 
high 
turn 1 
Inches 
Bd.ft. 
Inches 
Bd.ft. 
Inches 
Bd.ft. 
12 
60 
26 
560 
40 
1,300 
14 
80 
28 
660 
42 
1,410 
16 
120 
30 
770 
44 
1,530 
18 
180 
32 
870 
46 
1,660 
20 
270 
34 
970 
48 
1,790 
22 
350 
36 
1,080 
60 
1,930 
24 
450 
38 
1,190 
1 The " turn' is the round trip of the main line from the machine to the woods and return. 
This shows cost in terms of output per turn. In general the 
time, and hence the crew cost, per turn is a constant, so that cost 
per thousand feet varies inversely as output. The average output 
for 18 and 20 inch trees is 225 board feet per turn. The average for 
80-inch trees is 770 board feet, for 40-inch 1,300 board feet, and for 
50-inch trees 1,930 board feet or, respectively, 8.4, 5.8, and 8.6 times 
as great as for small trees. 
Bruce found on three operations (6) that "it costs from five to 
eight times as much per thousand board feet to yard logs from 18- 
inch as those from 48-inch trees, and that for trees below 18 inches 
in diameter the costs are undoubtedly even higher." 
The yarding cost is an important element in the total cost of pro- 
ducing lumber. Without going into elaborate calculations it seems 
certain that small trees themselves are handled at a loss, and that 
by logging them the cost per thousand feet is raised for the entire 
stand. But even assuming that such trees have the same stumpage 
values as the average for the stand, the average investment per 
thousand feet of the total cut represented in leaving them standing 
will not ordinarily exceed 27 cents. 
These studies at least raise the question whether after all the 
leaving of small trees for seeding purposes, as contemplated under 
a 20-inch diameter limit, will involve a serious additional cost to 
the operator. 
