40 



INDIRECT UTILITY OF FORESTS. 



observations. Those made in Bavaria and Prussia show the 

 following results : — 



These data show that evaporation in the forest was only 

 two-fifths of that in the open country. 



The effect of this action is that of the water which falls on 

 the ground in a forest a considerably larger proportion is 

 secured to the soil than in the open. It has been estimated 

 that about twice as much water penetrates into forest soil 

 as into soil in the open country. That water is available 

 to be absorbed by the roots, while any balance goes to the 

 underground reservoirs, and helps to feed springs. Of con- 

 siderable importance in this respect is the covering of forest 

 soil. Dr. Ebermayer's observations on this point, e.\tending 

 over 5 years, show the following results : — 



Parts. 



Evaporation of water from soil in the open })laced at = 100 

 Evai^oration from forest soil, without leaf-mould . = 47 

 ,, ,, ,, „ with a full layer of leaf- 

 mould . . . = 22 



In other words, forest soil without leaf mould evaporated 

 less than half the water evaporated in the open, while forest 

 soil covered with a good layer of humus evaporated even less 

 than one-fourth of that evaporated in the open. 



The result of these peculiarities is that forest soil retains, 

 after allowing for evaporation, more water, than soil in the 

 open, although some 23 per cent, of the rainfall is intercepted 



