For over 75 years, the USDA 

 Forest Service through its 8 regional 

 research stations with numerous 

 field laboratories, has overseen for- 

 estry research programs aimed at 

 protecting, managing, using, and 

 replenishing our forest resources. 



Besides such research the USDA 

 Forest Service cooperates with state 

 agencies and private forest owners 

 to stimulate proper management 

 practices and to protect the 440 

 million acres of their forests against 

 fires, insects, and diseases. 



The Forest Service also manages 

 187 million acres of public land, 

 including 154 National Forests and 

 18 National Grasslands in 43 states 

 and Puerto Rico. Each National For- 

 est resource — timber, water, forage, 



fish and wildlife, and recreation — 

 is managed to produce a harmoni- 

 ous environment along with tangible 

 benefits for all of America's people. 



$2 This booklet is based, in part, 

 on the air pollution research work 

 of USDA Forest Service Plant Pathol- 

 ogist Dr. Leon S. Dochinger of the 

 Forest Insect and Disease Laboratory 

 in Delaware, Ohio. At Delaware the 

 Forest Service is engaged in research 

 work aimed at determining the 

 responses of hardwoods and soft- 

 woods to t he various pollutants. 

 Through this research the Forest 

 Service is helping trees make life 

 more tolerable on earth for man — 

 in this century, as well as in the next 

 century. $& 



Issued October 1973 



This leaflet was originally issued by the USDA 

 Forest Service, Northeastern Forest Experi- 

 ment Station, Upper Darby, Pa., as "Our Air: 

 Unfit For Trees," in August 1972. 



* U.S. GOVERNMENT PRINTING OFFICE : 1973 O — 519-977 



For sale by the Superintendent of Documents, U.S. Government Printing Office 



Washington, D.C. 20402 - Price 25 cents 



Stock Number 0100-02959 



