FOREST INFLUENCES. 

 Soil temperature* ( 'outinued. 



319 



Flo. 43. Difference of temperature ( W O) at the depth of 4 feet. (The line running under the name 

 of a station is its zero line. The curve for the station is represented by the nearest broken, unbroken, 

 or dotted line like that in the margin.) 



Fia. 44. Differences of soil temperature (woods and open fields). Comparison of 

 deciduous and evergreen trees (WO). 



