WORK OF THE UNITED STATES FOREST SERVICE 29 
forests after fire, changes in the growth and quality of forests after 
recurrent fires, and many other related problems are being studied. 
FOREST INFLUENCES 
Closely coordinated with the research in forest and range manage- 
ment are investigations in forest influences. This research has for 
its purpose the determination of the effect that forests, brush, and 
other natural cover have upon water, soil, and climate. Studies are 
under way at a number of the forest experiment stations to determine 
these relationships and especially to work out the extent to which 
: F-278_-05 
FIGURD 22.—Thinning lodgepole pine stand, Medicine Bow National Forest, Wyo. 
the natural vegetation may be supplemented by minor engineering 
works and whether or not cutting of timber, grazing of livestock, and 
other uses of the forest and range cover affects adversely the water 
flow. 
One major concern is the influence of forests on floods. Under the 
recent Flood Control Act the Forest Service has a very important 
part in the program of the Department of Agriculture in determin- 
ing the measures which should be taken on the watersheds in order 
to provide for the control of water on the land. Foresters believe 
that 1f water can be controlled at the place where the rain falls, or the 
snow melts, such control will have a marked bearing upon other 
flood-control operations in the major waterways. 
FOREST PRODUCTS 
Research in forest products is designed to increase the value of the 
forest crop through improvements in wood utilization, the develop- 
ment of new uses for wood, and the utilization of waste and of tree 
