CONTENTS 



Page 



Introduction 185 



The basis for evaluating timber destruction 185 



Growth impact — the concept and definition 185 



Interrelations of causal agencies 186 



Forest protection as analyzed in past national 



appraisals 186 



The growth impact of forest damage occurring in 



1952 187 



Destructive natural agencies take heavy timber 



toll 187 



Mortality versus growth loss 189 



Status of protection from fire 189 



Fire protection in relation to the timber resource. 189 



Timber losses due to fire 190 



Total impact on growth is substantial 190 



Total growth loss exceeds mortality 191 



The current forest fire situation 192 



Man-caused fires still a problem 192 



Area burned in 1952 near current average 192 



Burned area mostly on private land 192 



A look at the status of fire control 194 



Major milestones in fire control 194 



Eighty-eight percent of lands now protected. . 195 



Most unprotected land is privately owned 196 



Intensity of protection varies greath' 196 



Effective fire control expenditures unchanged 



in recent years 197 



Current trends toward better fire control 199 



Man-caused fires can be reduced 199 



Protected area being increased rapidly 201 



Intensification of fire control is big challenge.. 201 



Area burned is trending downward 202 



184 



Page 



Status of protection from diseases 203 



Diseases reduce our timber supply 205 



Many kinds of disease cause major losses 206 



Advances being made in disease control 208 



Disease surveys, the first step toward control. _ 208 



Direct control necessary against some diseases. 208 



Control through silviculture gaining ground.. 209 



Status of protection from insects 209 



Insect impact on timber growth 210 



Important timber losses caused by many types 



of insects 210 



A new age in insect control 211 



Survey's are basic to detection and control 211 



Most major insects now combated bj* direct 



measures 212 



Biological control — a new tool against forest 



insects 213 



Insect control through silvicultural modifica- 

 tions 213 



Opportunities for salvaging insect-killed timber 



improving 213 



The impact of animal damage on timber growth.. 214 

 Many kinds of animals impede growth and 



regeneration 214 



Animal damage can be controlled 215 



Weather effects destructive to timber 215 



Catastrophic timber destruction since 1900 216 



The outlook for reducing timber losses 218 



