ATTENTIONS TO GIVE TO THE SOIL. 455 



and where these are absent or insufficient, also shrubs and under- 

 shrubs, and even grasses and herbaceous weeds. 



We know that winds accelerate the evaporation of soil moisture 

 in a very marked manner. They should hence be kept out of 

 forests as much as possible, and in exposed places, such as the edges 

 of the forest, sharp ridges and peaks, saddle-backs, the sides of 

 roads, &c., their effects should be diminished by raising fringes 

 several yards wide of evergreen trees or at least of trees that retain 

 their leaves throughout the whole or the greater part of the hot 

 weather. These fringes should be worked either as coppice or by 

 jardinage, or be felled only after obtaining a complete advance 

 growth, supplemented, if necessary, by artificial means. The 

 fringes will also break the force of the wind and, by throwing it up, 

 prevent it from entering under the trees beyond. 



Hillsides, as we know, dry up very easily, firstly, because the 

 gradient accelerates drainage, and, secondly, because the wind 

 impinges directly upon them ; and the steeper the slope is, the 

 more immediate is the result. Hence, on all steep hillsides we 

 should have either jardinage or regeneration in groups, and we 

 should carefully preserve all shrubby growth as well as weeds not 

 interfering with reproduction. Where there is no danger of 

 erosion, the soil may be hoed up, the clods checking surface drain- 

 age and retaining a very large quantity of water for some time 

 after the last shower of rain has fallen or the snow has melted, as 

 the case may be. Although the cost of a single hoeing is heavy, 

 yet the effects last for many years, and if the cost is distributed 

 over those several years, the average figure per annum becomes 

 trifling indeed compared with the amount of good secured. But the 

 most effective method of utilising atmospheric precipitation on a 

 dry slope is to excavate short horizontal trenches, each line of 

 trenches breaking bond with the lines immediately above and below 

 it (see p. 261, para. 3 and p. 258. para. 2). 



Irrigation and drainage need not be referred to here, as we 

 have already, at pp. 239-40 and 223-8 respectively, said all that 

 need be given in this Manual regarding such work. 



Richness. 



Obviously no direct manuring on any appreciable scale is possi- 

 ble in forests ; but, on the other hand, some new soil is always 

 formed by the weathering and disintegration of rocks and stones, 

 and the dead leaves and other vegetable disjecta restore to the soil, 

 in the most highly concentrated and utilisable form, mineral mat- 



