The World Forest Situation 



749 



to occur irregularly, and many losses 

 of wood caused by disease are con- 

 cealed within the boles of trees. 



Nevertheless, some countries have 

 solid estimates of both total and net 

 growth obtained under management, 

 so that it is possible to appraise what 

 the productive forests of the world can 

 produce. It must be emphasized that 

 such an appraisal assumes reasonably 

 good management that is, keeping 

 forest lands productive. 



The reported present growth rates 

 for coniferous forests in Europe range 

 downward from 104 cubic feet per acre 

 in Denmark to 2 1 for Great Britain and 

 23 for Poland. The figures for Great 

 Britain and Poland reflect devastation 

 of forests during the war. The average 

 of the rates reported is about 31. It is 

 fair to assume that as the forestry pro- 

 grams are expanded, this rate can be 

 increased to not less than 43 cubic feet 

 per acre. 



An unofficial estimate of growth in 

 the coniferous forests of the Soviet Un- 

 ion is 28 cubic feet per acre. It would 

 be unwise to assume a higher average 

 for the future, because of the northerly 

 location of many of the forests. 



In Canada the current rate of 

 growth of coniferous forests is about 

 14 cubic feet per acre, and an attain- 

 able rate of 28 can be assumed as bet- 

 ter management is applied. 



In the United States the reported 

 growth rate of 33 cubic feet per acre 

 reflects the high-growth potential of 

 many of the coniferous forest lands. 

 It is estimated that improved manage- 

 ment could increase the average to 57. 



All in all, the accessible coniferous 

 forests of the world, with reasonably 

 good management, could be made to 

 produce an average net yield of about 

 31 cubic feet per acre, or a total of 

 more than 40 billion cubic feet. The 

 present normal use of coniferous wood 

 is estimated as about 26 billion cubic 

 feet. 



The inaccessible coniferous forests 

 are not likely to attain rates of growth 

 as high as are assumed for the accessi- 

 ble forests, because growing conditions 



are generally less favorable. But the 

 986 million acres of inaccessible conif- 

 erous forests, as put under manage- 

 ment, should yield an annual average 

 growth of 22 billion cubic feet. 



Thus, with reasonably good man- 

 agement, the coniferous forests of the 

 world could be made to yield continu- 

 ously well over twice the amount of 

 wood now normally used and lost. That 

 result cannot be expected in a short 

 time, and an expansion of the current 

 rate of consumption of the coniferous 

 wood is not safe at the present time. 



About 64 percent of the total pro- 

 ductive forest area of the world con- 

 sists of broadleaved species. Of this, 

 about 14 percent is temperate hard- 

 woods and 50 percent tropical hard- 

 woods. 



In Europe and in North America, 

 the present estimated growth of the 

 temperate hardwoods is about the 

 same as for coniferous forests. We esti- 

 mate that these rates of growth can be 

 increased substantially. 



In the tropical broadleaved forests, 

 only a few of the many species are 

 being exploited. For the merchantable 

 species only, annual growth rates of 

 7 to 21 cubic feet per acre have been 

 estimated. Growth as high as 100 cubic 

 feet per acre has been estimated as 

 attainable where it is possible to use 

 all the species, including those that are 

 at present unused. 



The future productivity of the trop- 

 ical hardwood forests thus depends on 

 finding uses for many more species, 

 and, most important, on curbing the 

 current rates of forest destruction 

 through controlling the practices men- 

 tioned earlier. 



The world can have a far larger 

 supply of wood than it now uses, and 

 can have it permanently, if the pro- 

 ductive forests are given reasonably 

 good management. 



ONE OVER-ALL MEASURE of the for- 

 est-management situation is the rela- 

 tion between average growth and 

 drain on the accessible productive for- 

 ests, that is, those that have been or 



