568 PROTECTION AGAINST SNOW. 



plants may, however, be uprooted, at least at high altitudes, 

 owing to the large surface of their crowns, so that wherever 

 this danger is to be feared planting- spots must not be too far 

 apart. 



Observations made in the Harz forests in December, 1883, 

 after the disastrous snow-storm already referred to, gave the 

 following percentages in 100 acres of spruce woods which were 

 bent down and broken by the snow : 



Single planting, 18, 

 Multiple planting, 26, 



so that the single planting suffered about one-third less than 

 multiple planting. 



Mixed woods consisting of broadleaved trees and conifers 

 suffer less than pure coniferous woods, as less snow rests on 

 the trees, and the broadleaved species are less liable to injury. 

 Beech, sycamore and hornbeam should therefore be mixed 

 with spruce or silver-fir. The larch has not succeeded in 

 German mountain-forests, but it grows admirably in the 

 British Isles when mixed with beech and other conifers, pro- 

 vided the soil is suitable, and such mixtures are well adapted 

 to withstand heavy falls of snow. 



ff. Effect of Thinnings. 



Woods which have been properly thinned are generally less 

 liable to damage than unthinned woods, not only on account 

 of the sturdier forms of the trees and their more regular 

 crowns, but also because more snow reaches the ground in 

 thinned woods, and the weight of the snow which rests on the 

 crowns of the trees is less than when the woods are very 

 dense. The wind is also more effective in thinned woods in 

 shaking the trees free from snow. 



Extensive snowbreak has indeed been observed at times in 

 thinned woods, but this does not invalidate the above reason- 

 ing, for sometimes thinnings are put off too long, and if 

 excessive snow should fall on weakly stems just set free by 

 a strong thinning, it is evident that much damage may be 

 done. It is therefore to a certain extent an affair of chance, 

 as regards the first thinning in a dense thicket, whether 

 damage by snow occurs or not, but the longer the wood 



