24 FOREST BELTS OF WESTERN KANSAS AND NEBRASKA. 
rivers are preeminently sandy streams with shifting beds, so that 
timber growth is either wholly absent from them over long stretches 
or consists only of scattering cottonwoods and willows. <As_pre- 
viously mentioned, the smaller streams which are less sandy support 
other species, principally green ash, white elm, hackberry, and box 
elder. 
Tn Kansas, as far west as the one hundredth meridian, nearly every 
stream has its fringe of timber, and there is considerable diversity 
in species; but both the quantity and variety decrease westward, 
until at the Colorado line timber is very scarce, and occurs mainly 
on the Smoky Hill and Arkansas rivers. Along the tributaries of 
the former stream, in Russell County, near the center of the State, 
there are found cottonwood, willow, red and white elm, black 
walnut, bur oak, hackberry, box elder, green ash, red cedar, red 
mulberry and wild china; while in Wallace County, on the western 
border, there are only a few groves of cottonwood and willow. The 
best westward extension of timber in Kansas is on Beaver Creek, in 
Rawlins County. The creek is bordered by a thriving growth of 
green ash, with a lesser number of several other species. The timber 
reaches to some distance above Atwood, not far from the point where 
the bed of the stream first carries permanent water. (See Table XI.) 
In Nebraska there is likewise a progressive lessening in the number 
of species as one goes westward, until the foothill region is reached, 
when the increased altitude causes the appearance of Rocky Mountain 
forms. In Butfalo County, for instance, the species found are bur 
oak, green ash, box elder, white elm, hackberry, cottonwood, and 
willow. Farther west, in Deuel County, the box elder, elm, and oak 
are missing, while in Scotts Bluff County occur box elder, several 
willows, lanceleaf, narrowleaf, and common cottonwood, green ash, 
hackberry, valley mahogany, western birch, western serviceberry, 
and dwarf maple. Sioux County, in the extreme northwest, has 
the greatest variety of trees and shrubs of any county covered by 
this report. 
The trees of the valley type are commonly quite vigorous, though 
many of them are relatively short lived. Considerable damage 1s 
done by borers, and in some localities the ash is badly injured by 
them as well as by heart rot. Galls on the twigs of various species 
are occasionally abundant, and leaf-eating insects do more or less 
harm. Many of the broadleaf trees in the draws and canyons of 
Pine Ridge are in bad condition. Growth is slow and scrubby, and 
dead limbs and tops are common. Scars from old burns are found, 
but the apparent reason for the general unhealthfulness is that the 
cutting of the pine of the higher land has lessened the amount of 
water about their roots. | 
