18 PROTECTION OF WOODLANDS. 



the subsequent crop, should be retained with a view to the pro- 

 tection of the soil until the formation of the young crop is 

 well advanced or nearly complete. 



Where natural reproduction seems inadvisable, narrow annual 

 falls should be made running from north-west to south-east, and 

 gradually advancing annually towards the south-west ; thus the side 

 of next year's mature fall protects the youngest crop from the 

 hot mid-day sun, and often proves more beneficial than direct 

 overshadowing. 



On hillsides with southern or western aspects, thinnings must 

 take place very carefully, and should not be carried out strongly. 



The retention of the annual fall of leaves and needles, and the 

 utmost possible restriction of their removal for agricultural or 

 domestic purposes, are also of great importance, especially on hill- 

 sides ; for the layer of leaves or moss not only acts mechanically in 

 preventing evaporation of the soil-moisture, but also hinders the 

 rapid running off of water received as rain or snow, and gives it 

 time to percolate into the subsoil after the soil has itself become 

 saturated with moisture. By means of protective belts of densely 

 foliaged species planted thickly along the edges and outskirts of 

 woods, the penetration of winds likely to exhaust the moisture 

 from the soil, and to blow away the dead foliage, can to a 

 great extent be prevented. 



Although mainly intended to form a protection against the; 

 rapid running off of rain water (see par. 15), the formation of 

 horizontal ditches also acts as a means of retaining and increasing 

 the amount of moisture in the soil. 



For nurseries and seed-beds care should especially be taken 

 to select sites neither exposed to insolation nor to the action 

 of drying-up winds ; seeking the shady side of older crops, and 

 avoiding, as far as possible, localities exposed towards the south or 

 west, are much to be recommended. 



Both for nurseries, and for sowing in the open, a deep loosening 

 of the soil, to be repeated at times between the seed-rills and 

 seedling-rows in the former, appears to assist in retaining the soil 

 moist, as the atmospheric precipitations can penetrate more easily 

 and deeply. The larger interstices between the particles of soil 

 prevent rapid capillary ascension of moisture to the surface, and 

 thus maintain a greater degree of moisture in the portion of soil 

 occupied by the roots. At the same time, in loose, porous soil the 



