FOREST TREES AND FOREST SCENERY 
smaller plants—so long as their root 
systems are not too dense and intricate 
— are of value on account of their ame- 
liorative effects on temperature and 
moisture. This is more important in 
this country, so extreme in its climatic 
variations, than in northern Europe. 
In the dry and parching days of sum- 
mer the shrubbery of the woods, by 
its shade, helps to keep the earth cool 
and moist. This mantle of the earth, 
moreover, conducts the rain more grad- 
ually to the soil, exercising an efficient 
economy. In the fall and winter the 
shrubs, which are densest near the for- 
est border, help to break the force of 
the sweeping winds which might other- 
wise carry away the fallen leaves, so 
useful in their turn because they are 
conservators and regulators of mois- 
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