Periodical Literature. 257 



diameter of each glade being so proportioned to the height of tlie 

 trees around it that the sndw in early spring is effectually screened 

 from the sun. He also recommends the planting of tree screens at 

 strategic points on exposed slopes to increase their capacity to 

 store snow. The investigator believes that there can no longer 

 be any question of the direct influence of forests in delaying the 

 melting of snow, and thus in retarding stream flow at the very 

 time when floods normally occur. A forthcoming bulletin by 

 Prof- Church, giving the results of detailed investigations on this 

 timely subject, will be awaited with interest. 



Scientific American Supplement. September 7, 1912- Pp. 152-155. 



SILVICULTURE, PROTECTION AND EXTENSION. 



Dr. Beck in an inaugural address before the 



Light Tharandt forest school sums up in a com- 



in plete, lucid and interesting manner the func- 



Forest tion which light plays in tree development 



Management. and forest management. 



Vegetation is determined primarily by 

 climate, soil being a ruling factor only within climatically equal 

 regions. Warmth and light are among the most important fac- 

 tors of cUmate, and have for a long time been subjects of in- 

 vestigation. On account of the ease of its measurement and 

 observations in the work of plant ecologists, temperature has 

 been given more prominence than light. 



While the significance of the latter has been recognized for a 

 long time, its use as a factor of management has rested more on 

 instinct and practice-won skill than on exact knowledge of its in- 

 fluence. But of late years, especially in the past three decades, 

 the work of such men as T. Hartig, H. Wiesner, and more re- 

 cently Prof. Cieslar and M. Wagner, has furnished much useful 

 information on the subject. 



The subject is discussed from two standpoints, viz: the physi- 

 ological and managerial significance and use of light- 

 It is known that light plays a very important role in growth 

 and form relations, volume and value production of both indi- 

 vidual trees and stands, but it is difiicult to correctly gauge the 

 share of light in this, since it is but one of many factors, such as 

 temperature, moisture, soil, etc., acting in combination. But 



