RESULTS OF CUTTING IN THE SIERRA FORESTS. 25 
The favoring of yellow pine and sugar pine by leaving abundant 
seed trees of these species and marking white fir and incense cedar 
closely has resulted in no change in composition, because few new 
seedlings of any kind have come in; there always remain enough 
unmerchantable firs and cedars to supply abundant seed; light cut- 
ting, heavy litter, brush, and ground cover favor fir and cedar; and 
on certain sites, if fire or heavy cutting are excluded, fir naturally 
succeeds pine. 
Attempts to control brush and ground cover by marking methods 
without eradication or planting are not successful, because the nat- 
ural stands are already sufficiently open to permit survival of many 
shrubs where yellow-pine reproduction is excluded. Cutting of any 
kind favors extension of the brush. With fire protection, suppres- 
sion of such shrubs depends, for the present, on the slow process of 
competition by which the brush is overtopped by the tree seedlings, 
especially those of white fir. 
Marking designed to promote natural regeneration should give 
primary consideration to existing advance reproduction. Cutting 
should be as heavy as management restrictions allow in order to 
release it. Every precaution should be taken in felling, yarding, 
and brush burning to preserve it. Its presence will shorten the 
rotation 5 to 20 years or more. 
Brush disposal by piling and burning results in covering by fire 
at least 6 to 10 per cent of the area, on which a considerable number 
of seedlings and saplings are destroyed, and costs from $8 to $10 
per acre. Leaving slash rarely induces insect infestation. Cleared 
control lines with intensive protection may ultimately supersede 
piling and burning of slash. 
The best advance reproduction in nature has occurred under con- 
ditions resembling a shelterwood system. When reproduction is 
absent and the stand essentially even-aged, a heavy shelterwood, or 
a seed-tree cutting, leaving numerous well-distributed seed trees 
preferably larger than 18 inches, will combine the most favorable 
conditions for improved growth and reproduction. In irregular 
stands a heavy selection cutting, removing 75 to 80 per cent of the 
volume, and avoiding grouping of the reserved trees as much as 
possible, promises to give the best silvicultural results. Each acre 
is a problem in itself and much depends on the marker's ability to 
recognize the character of the site, the mature stand and reproduc- 
tion requirements, and to apply the right silvicultural principles as 
a part of the broad marking policy by which he is guided. 
