24 PROTECTION OF WOODLANDS. 



and moss, together with the humus or vegetable mould formed by 

 their gradual decomposition, imbibe, with sponge-like absorptive 

 power, large quantities of moisture, which they retain and only 

 gradually part with again to the soil and the atmosphere. In 

 most countries the maintenance, tending, and economic treatment 

 of such protective woodlands is provided for by law. 



The formation of horizontal ditches for catchment of the water, 

 is a measure that has found extensive application in recent years. 

 The ditches, running horizontally along the hillsides, are formed 

 about 12 inches deep, and in parallel lines about 16 to 32 feet 

 apart, according to the steepness of the slope ; as they not only 

 catch the water flowing down from below the ditch immediately 

 above, but retain it to percolate gradually into the soil below, 

 they work beneficially in a double manner (see par. 12). 



Sowings on slopes should always be carried out in horizontal 

 rills or bands, as otherwise the seed is apt to be washed away by 

 the down-pouring rain. Although the formation of nurseries on 

 soil with a steep gradient should be avoided as much as possible, 

 yet this cannot always be helped in mountainous tracts. Where 

 this is unavoidable, something can always be done to improve 

 matters by terracing the ground, placing the seed-beds and the 

 paths between them horizontally, leaving bands of unbroken soil 

 with its original covering of weeds, &c., between the beds, so 

 to check any tendency to scouring of the soil, and formation oi 

 narrow seed-beds in place of larger patches or seed-plots. Ttu 

 washing away of the seed can be prevented by covering the 

 with branches, moss, or frame-work. 



B. SNOW. 

 16. Damage caused by Snow. 



So long as the snow is dry, and does not fall in too large 

 quantities, it does no damage to woodlands ; on the contrary, it 

 protects young growth from damage at the time of felling am 

 extracting timber when the standards are being cleared, makes 

 extraction easier, prevents the roads being badly cut up, and is 

 one of the chief sources whence are obtained the winter moisture 

 so necessary for the well-being of timber crops during the summer. 



But when the snow falls in moist, large flakes, and accumulates 

 in large quantities on the leaves, twigs, and branches of conifei 



