48 WESTERN YELLOW PINE IN ARIZONA AND NEW MEXICO. 
of timber must in the future be available for purely local industries. 
Waste by private owners, even if it amount to only 5 or 10 per cent 
of their total cut, will mean a shortage in the future timber supply 
of the Soules 
In managing western yellow pine, therefore, it is essential that 
provisions be made for a sustained annual yield. This does not mean, 
however, that only the annual growth will be cut. In the average 
virgin forest growth is offset by decay. Most of the stands on the 
national forests in the Southwest are virgin, and consequently the 
mature timber that goes to waste each year is a great loss. It is true 
that this natural loss is offset theoretically by the growth of new 
stands, but full use is not made of the forest unless the mature timber 
is cut and the thrifty growing immature stands left for future needs. 
Moreover, it is the desire of the Forest Service not only to maintain 
a sustained annual yield, but to improve the quality of the timber 
as well. If only timber of the lower grades is produced, export ship- 
ments will suffer. It is therefore particularly essential, on account 
of the long hauls and consequent heavy freight rates, that a fair 
proportion of higher grades be supplied. Yet the Forest Service is 
bound to dispose of all over-mature timber, and if this is done the 
annual cut must be more than the estimated annual growth of the 
normal forest. It will be necessary not only to dispose of the annual 
growth, but also to reduce the excess growing stock represented by 
virgin stands. For instance, if there were 100,000 acres, every one 
fully stocked to its full capacity, under normal conditions it might 
be the duty of the Forest Service not only to cut the actual annual 
increment, but also to reduce the excess growing stock to what would 
be considered normal—in this case one-half the present mature stand. 
METHOD OF CUTTING. 
The regulation of the cutting of western yellow pine depends upon 
the method of cutting, which in turn must be governed by the silvical 
requirements of the species. In the past the cutting in Government 
timber sales has removed about two-thirds of the stand. Wherever 
possible, the one-third left standing has been selected from thrifty 
blackjack, though frequently it has been necessary to retain mature 
trees. It is planned to return and cut this one-third of the original 
stand as soon as reproduction is complete. It is not known how long 
the reproduction period must last, but probably 15 years, and per- 
haps 20, will pass before satisfactory regeneration takes place. The 
present method of cutting might be termed a group selection, or a 
primitive application of the shelter-wood (femelschlagbetreib) sys- 
tem applied to irregular stands. At all events, the idea has been to 
prepare for a second crop by cutting two-thirds of the original stand, 
and when the new crop is established to cut the remainder. 







