88 FOREST PROTECTION 



area, the condition and improvement of the soil for reproduction, and 

 growth rate of the stand. Decay in hardwood logs left on landings 

 or decks during warm weather is also an important phase of the 

 subject. Recent investigations have added to the knowledge of the 

 proper chemicals to use in preventing sap stain on pine, gum, and 

 yellow poplar lumber cut in the South. 



10. DOMESTIC ANIMALS 



The grazing of cattle has done considerable damage to forests, 

 particularly to hardwood reproduction and young growth in farm 

 woodlots of the Ohio and Mississippi Valleys. Horses, sheep, swine, 

 and goats may also inflict considerable damage on the forests through 

 over-grazing or in other ways. Swine frequently dig up the young, 

 fresh, succulent roots of longleaf pine in the South and destroy much 

 reproduction. 



Throughout the Rocky Mountains and parts of the Pacific Coast 

 forests, open forest types such as ponderosa pine and aspen furnish 

 excellent forage for cattle, horses, and sheep and concurrently, if prop- 

 erly controlled, may provide good wood crops. 



The Forest Service estimates that approximately 246,000,000 acres 

 of commercial forests are grazed every year. This means that sub- 

 stantially one-half of our total commercial forests are grazed. The 

 largest percentage of forest grazing is in the South, where 67% is sub- 

 ject to grazing, chiefly by cattle. 



The pasturing of woodlots in some sections, as in Ohio, Indiana, 

 and Michigan, has destroyed much young growth and reproduction. 

 Over-grazing may have serious effects upon the soil as well as upon 

 prospective reproduction and young growth. Grazing in some regions 

 tends to keep down the grass and therefore lower the hazard from 

 forest fire. In Ohio woodlots, the returns from timber growing are 

 estimated at several times the returns from pasturing livestock in the 

 same areas, according to Tillotson. In the California pine region, the 

 value of timber growth per acre per annum is estimated at 50c per 

 acre contrasted with 15c or less per acre for grazing on the best areas, 

 according to Show and Kotok. 



11. WILD ANIMALS . 



Many animals which use the forests as their native habitat may 

 cause considerable damage to the forest. Deer may do much harm to 

 small trees and reproduction by eating not only the leaves but also 



