86 ENGLISH WOODLANDS 



the depression may materially improve the tem- 

 perature of the lower land. 



Caution must be used in making plantations 

 on low land, for shelter from the wind is not 

 always desirable. Drying winds are often bene- 

 ficial ; if they are excluded and the sunlight 

 obstructed, damp land may become sour. 



