PPcEPER ARTICLE. 
ORIGIN OF TIMBER BELTS. 
In the north central part of Kansas along the Republican river in 
Clay and Cloud counties, the streams are bordered by narrow inter- 
rupted belts of timber. These belts are from a few rods to half a mile 
in width. The region is near the border line of the great plains, east 
of the Rocky mountains, where trees are almost entirely absent. Until 
recently the country was swept annually by devastating prairie fires, 
and it was only on the sandbars, on the inner side of the river bends 
where the sedimentary deposits were comparatively free from herbage, 
that young trees had any chance of surviving. In the region studied, 
the Republican river passes through the Dakota sandstone, and its bed 
is very sandy. During overflows the lower portions of the bends are 
covered by a layer of sand and rich organic detritus, affording a0 
immediate substratum for the vigorous development of young trees, 
while at the same time the growth of grass and weeds is almost entirely 
checked because they are partly or completely covered up by te 
deposits. ; 
The succession of woody plants is as follows: Along the waters 
edge or at the outer margin of the sandbars, there first grows UP @ 
zone of the common long-leaved willow, Sa/ix longifolia Mubl. As 
this advances with the growth of the bar, it is replaced by the black 
willow, Sa/ix nigra Marsh. The black willow finally gives way to a 
thick growth of cottonwood, Populus monilifera Ait. All young timber 
belts are therefore made up of three zones: ve 
1. A zone of Salix longifolia Muhl., generally several rods in ers 
2. A strip of Salix nigra Marsh, usually a narrower zone than the 
first. 
3. A wide zone of Populus monilifera Ait., which makes UP 
ber belt proper. 
I have had some of these young timber belts unde hat 
nearly twenty years, some from their very beginning, and 1 hae} . 
it is only after the cottonwood has formed a rather thick forest of 8°° ; 
sized trees that other trees common to the region begin to take aso 
the tim- 
+ observation for 
