90 



FOREST PROTECTION 



wood due to sudden and severe cold. They are sometimes followed by 

 long, projecting ribs, called frost ribs. Hardwoods with large medul- 

 lary rays, such as oak, beech, and sycamore, are especially susceptible, 

 as also are elm, ash, and chestnut. Other phases of forest protection 

 include damage by wind and ice storms and the theft of timber from 



FIG. 46. The greatest fire trap in the history of the United States. Billions of 



feet of Sitka spruce and western hemlock were windthrown by a tornado on the 



Olympic peninsula, Washington. 



the forest by mankind. Properly marked and established boundaries 

 are the best preventive for theft, which is usually unintentional. Many 

 damage claims have been made by federal authorities as well as by 

 private agencies as a result of the illegal cutting and logging of areas 

 in some parts of the country. 



