[Illustration:  FIG. 138.—­Government Foresters in Missouri Studying the Growth and Habits of Trees.  They are standing in water three feet deep.]

Where cutting is to be done on a National Forest, the conditions are investigated by a technically trained forester and the cutting is regulated according to his findings.  Special attention is given to discovering new uses for species of trees which have hitherto been considered valueless, and the demand upon certain rare species is lessened by introducing more common woods which are suitable for use in their place.

Aside from the perpetuation of the national forests, the U.S.  Forest Service also undertakes such tree studies as lie beyond the power or means of private individuals.  It thus stands ready to cooperate with all who need assistance.

STUDY II.  CARE OF THE WOODLAND

Almost every farm, large private estate or park has a wooded area for the purpose of supplying fuel or for enhancing the landscape effect of the place.  In most instances these wooded areas are entirely neglected or are so improperly cared for as to cause injury rather than good.  In but very few cases is provision made for a future growth of trees after the present stock has gone.  Proper attention will increase and perpetuate a crop of good trees just as it will any other crop on the farm, while the attractiveness of the place may be greatly enhanced through the intelligent planting and care of trees.

How to judge the conditions:  A close examination of the wooded area may
    reveal some or all of the following unfavorable conditions: 

The trees may be so crowded that none can grow well.  A few may have grown to large size but the rest usually are decrepit, and overtopped by the larger trees.  They are, therefore, unable, for the want of light and space, to develop into good trees.  Fig. 139 shows woodland in such condition.

[Illustration:  FIG. 139.—­Woodland which Needs Attention.  The trees are overcrowded.]

There may also be dead and dying trees, trees infested with injurious insects and fungi and having any number of decayed branches.  The trees may be growing so far apart that their trunks will be covered with suckers as far down as the ground, or there may be large, open gaps with no trees at all.  Here the sun, striking with full force, may be drying up the soil and preventing the decomposition of the leaves.  Grass soon starts to grow in these open spaces and the whole character of the woodland changes as shown in Figs. 140 and 141.

[Illustration:  FIG. 140.—­First Stage of Deterioration.  The woodland is too open and grass has taken the place of the humus cover.]