28 
the ground, has been studied on a typical national forest cutting 
area. Strips of one one-hundredths acre, 66 by 6.6 feet, were laid 
out and tallied before and after logging. Before logging 1,515 
seedlings per acre were found; after logging 975, or 64.4 per cent, 
remained. These were well distributed, only 7 per cent of the small 
plots showing complete destruction of advance reproduction. 
While this single series of data can not be regarded as conclusive, 
it indicates that about two-thirds of the advance reproduction, well 
distributed, survives. 
Similar data were also obtained for an operation on private land. 
In this case, of 1,280 seedlings to the acre in the virgin forest 605, 
or 47.3 per cent, remained after yarding. Although over half of 
the advance reproduction was destroyed, on only 1 out of 16 plots 
did logging wipe it out entirely; 94 per cent of the plots were left 
with advance reproduction. 
These data again, although not conclusive, agree well with ex- 
perience in showing decidedly more damage on unregulated private 
cuttings than on- supervised national forest cuttings. The latter 
may be considered to show what can easily be done if donkey yard- 
ing is properly regulated ; the former, what results from unregulated 
yarding. Although the survival of 47 per cent of the reproduction 
seems rather low compared with the 80 per cent on national forest 
wheel-logged land, it must be recognized that with any type of 
machine logging considerable loss is to be anticipated. The saving 
of practically half of the reproduction well distributed is very far 
from denudation. 
Examination of many operations, both national forest and pri- 
vate, old and new, shows that complete destruction of advance re- 
production or of seed trees is never chargeable to this method alone. 
On the permanent sample plots, for example, after ground-lead 
yarding, 1,270 and 5,460 seedlings per acre survived on typical 
areas in the yellow pine and mixed conifer types, respectively. 
This type of yarding is likely to be adjudged as more destructive 
than it really is, particularly if seen at the time of or soon after 
logging. The incoming logs and the line scar the bases of many 
trees, the fresh scars being very noticeable. (Fig. 8.) Data taken on 
the permanent sample plots show an average of 6.9 per cent of the re- 
maining trees injured in this fashion, but also show that recovery is 
rapid and death rate low. This figure is, of course, a minimum, and 
on unregulated private land the percentage of trees injured some- 
times runs as high at 25. Wounds which expose the heartwood are 
known to result commonly in infection by wood-destroying fungi. 
Logging wounds usually do not go so deep, but even more superficial 
wounds, if large enough, may prove to be a source of danger to the 
stand left after logging. 
Ground-lead logging makes a characteristic pattern. (Fig. 9.) 
Near the machine a high percentage of the ground is dragged, be- 
cause of the convergence of the many trails; but toward the outer 
edge of the logged area damage becomes progressively less. 
The emphasis on saving of advance reproduction, it may again be 
noted, would be of merely academic interest, were it not for the fact, 
discussed in detail elsewhere, that the principal part of the second 
stand, particularly in east side yellow pine, must come from that 
source. 
