PERIODICAL MTKRATUKK 81 



ev^erv two seconds. I'lic i)ine leaf is lluis far frcjiu being an inerl: 

 organ. Assuming that each cubic meter of air expired contains on 

 the average 20 grams of water vapor, which is certainly a maximum, 

 tlie leaves would transpire each year 151,000 kilograms of water per 

 hectare. Assuming further that evaporation from the leaves and other 

 parts of the tree is twice the transpiration, the total annual water re- 

 (luircment of the forest is approximately 500,000 kilograms per 

 hectare. This is equivalent to a water blanket over the surface of the 

 soil 5 centimeters in depth. In spite of so small a water requirement. 

 Scotch pine forests sometimes fail to produce a normal amount of 

 wood because they are in general relegated to soils which do not retain 

 capillary water well, because the humus which they produce improves 

 only slightly the physical properties of the soil, because the root hairs 

 occupy a comparatively thin layer of soil, and because the tree itself 

 has but little reserve capacity. While Scotch pine seldom dies of 

 drought, a soil which is dessicated during the growing season may thus 

 result in reduced wood production. Conditions may be considerably 

 improved by underplanting open stands wnth such species as beech 

 or hornbeam, which ])roducc a heavy leaf litter. S. T. D. 



Alorel, C. Activitc dc I'assimUation chlorophyllienne chez Ic pin sylvestre, 

 quantitc d'eau necessaire a la vegetation d'lme forct de cette essence. Rev. 

 Eaux et Forets. 58:16:5-100. 1920. 



The value of the high forest, long advocated 

 Conversion of by the leading French foresters as the forest par 

 Coppice Into excellence, was conclusively demonstrated bv the 

 High Forest recent war, during which it was primarily the 

 high forests under State ownership that supplied 

 the enormous quantity and wide variety of forest products required 

 by France and its allies. For both public and private owners the high 

 forest is superior to coppice in the quantity, quality, and variety of its 

 products, in its proportionately smaller cost of protection and greater 

 production, and in its flexibility of management, which is particularly 

 valuable in times of economic stress. The objection that it yields too 

 low a rate of interest has lost much of its force in these days when 

 timber prices are so high and most other investments so insecure. 

 Some sacrifice of annual revenue is involved during the period of con- 

 version, but this is purely temporary, can be minimized by proper 

 handling, and really consists of an addition to the forest capital com- 



