20 FOREST BELTS OF WESTERN KANSAS AND NEBRASKA. 
Muddy Gulch 17 little cedars were found, though there were no old 
cedar trees in the vicinity. 
ENEMIES. 
The common enemies of young trees everywhere are fire and stock, 
and the pine and cedar of Nebraska have not escaped their ravages. 
Fires have passed over much of the region at various times, and un- 
questionably have played an important part in determining the char- 
acter of the forest. The actual damage to the old trees may have been 
less than in many forest regions, vet there is little doubt that without 
the fires the present pine areas would have been larger and the stand 
less open. Since the settlement of the country fires have been checked, 
and testimony is unanimous that because fires are less frequent the 
sand hills are better grassed and the sand much more stable now than 
it was in the early days. 
Reproduction of the forest is hindered to a considerable extent by 
stock. The entire region is grazed by horses and cattle, principally 
the latter. Much of the young growth, however, is on steep slopes, 
where. because of the precarious footing and because of the unpala- 
table grass which grows in such situations, stock does not often go. In 
the bottoms of the draws and canyons, where the grass is better and 
water often appears, it is not uncommon to find the reproduction 
wholly ruined. In sandy soils the trampling of stock is extremely 
injurious to young trees, and there is little hope for good reproduction 
so long as grazing Is unrestricted. 
In some sections Insects are an additional menace to the pine. Now 
and then a tree is killed by bark borers, and considerable harm results 
from the work of worms in the cones. But by far the worst pest 1s 
the tip-borer.  Phis insect, in the larval form, destroys the terminal 
buds of the leading shoots and dwarfs the young pines until they can 
never make a growth of any value. During the season of 1901 this 
insect was common throughout the Pine Ridge region. The greatest 
damage was done in Dawes County and eastward along the Niobrara. 
In some stands of young pine, otherwise in fine condition, nearly all 
the terminal buds readily break off and crumble between the fingers. 
A striking illustration of the effect of a number of years’ work of 
this insect was afforded by ten trees found growing in a canyon in 
Sheridan County. They were in a sandy soil on a north exposure 
and would evidently have made good trees had they not been attacked 
by the tip-borer. Although these trees average 23 years of age, their 
average diameter at the ground was only 1 inch, and their average 
height but 32 inches. Their individual measurements are shown in 
the following table: | 
