TIMBER GROWING AND LOGGING PRACTICE IN CALIFORNIA 65 
The operator engaged in growing timber will be interested in 
increasing this percentage as much as possible and will desire to 
minimize logging damage. He can with profit employ measures 
that have proved valuable on national forest cuttings, in addition 
to those proposed in the first part of this bulletin. 
ADDITIONAL MEASURES TO INSURE BEST TIMBER GROWTH 
These additional measures concern chiefly the regulation of don- 
key yarding. By placing blocks and using shear trees to avoid 
pulling through areas of established young growth or reserved trees, 
by placing main lines so that they will not slash around and damage 
or kill reserved trees, it is possible to increase materially the quan- 
tity of reproduction saved. On national forest cuttings where these 
precautions are exercised in yarding, about 36 per cent of the 
advance reproduction is destroyed and 7 per cent of the seed trees 
seal-red, but not killed. On private lands the corresponding average 
losses are 53 per cent and 12 to 20 per cent. The results on national 
forest cuttings do not involve a material increase in logging cost, 
and show what can be done if preservation of reproduction is an 
object. 
One other feature of logging requi^ .s mention. Lack of care 
in falling timber ordinarily breaks fii or injures the crowns of 
part of the reserved trees, and always destroys a part of the advance 
reproduction. It has been estimated by Birch that the extra cost in 
falling on national forests amounts to only 1 cent per thousand 
feet cut, and it is only necessary to compare typical national forest 
and private cuttings to realize that this trifling expenditure means 
a real difference in the condition of cut-over lands. 
The experience of the past decade or more in logging national 
forest timber shows convincingly that the reduction of damage from 
various sources is neither impossible nor costly. As the various 
steps, such as care in felling and in yarding, are actually put into 
practice, it becomes more and more evident that very slight rear- 
I'angement of logging plans and practice makes all the difference 
between leaving the cut-over land in excellent or in only tolerable 
condition. 
Studies of extra costs of logging national forest stumpage (4) 
indicate that the cost due to care in yarding and in falling timber to 
avoid small trees and reproduction amounts to about 7 cents per 
thousand feet. 
The forest owner interested in building up his forest and capital- 
izing the opportunities for profitable growth will find his construc- 
tive effort centered largely on selection of trees to leave. Proper 
cutting methods, which leave on the ground an adequate number 
of effective seed trees and thrifty trees capable of rapid growth, 
constitute the chief factor in making timber growing most profitable. 
Fire protection, slash disposal, and logging restrictions, important 
as they are, primarily aim merely to prevent denudation. 
ADDITIONAL MEASURES IN CUTTING PRACTICE 
The simple cutting measures discussed in the first part of this 
bulletin do not approach the standard maintained on the national 
forests. They provide merely for an adequate number of small 
