Canadian Forestry Journal, June, 1920. 



283 



where the warm west winds of the 

 winter and early spring, known as 

 "chinooks," do great damage to win- 

 ter wheat and orchards. 



EFFECT ON TEMPERATURE 



The farmer who has cultivated 

 crops on a hot summer day need 

 hardly be told that the warmest part 

 of his field is the portion which is 

 sheltered from the wind. In the lee of 

 the windbreak there is not only no 

 breeze to cool the body and reduce 

 what is known as the "sensible tem- 

 perature," but the actual temperature 

 of the air is raised. Tests with a 

 thermometer has shown that the area 

 which is protected by a windbreak 

 may be several degrees warmer dur- 

 ing the day and several degrees cool- 

 er during the night than adjacent 

 areas not protected. 



Such crops as corn are benefited 

 very greatly by warm, sultry days. 

 The windbreak helps to create these 

 conditions and offsets to some extent 



the effect of cold, cloudy weather. 

 The cooling effect at night is of course 

 unfavorable to growth then ; but the 

 night is a period of comparative rest, 

 so that the nocturnal cooling off is 

 far more than counterbalanced by the 

 higher temperatures secured during 

 the day. 



WHAT ABOUT ORCHARDS 



Windbreaks may appear imdesir- 

 able for the protection of orchards in 

 blossom or garden crops which are 

 not hardy, because the danger of still 

 frost seems increased by the stagna- 

 tion of the air on the lee side. The 

 added danger is more apparent than 

 real, however, for still frosts only 

 occur when there is practically no 

 wind, and a windbreak can then have 

 little effect one way or the other. 

 Furthermore, complete stagnation of 

 the air may be helpful rather than 

 harmful if smudging is resorted to. 



The freezing which often causes the 

 most severe damage to orchards is 



How much of Prince Edward Island's abundant agricultural prosperity is due to the protection afford- 

 ed by belts of trees? No section of the Dominion enjoys a less interrupted prosperity, nor is the pastoral 

 beauty of Prince Edward Island easily surpassed. 



