SNOWBREAK. 567 



Switzerland, in 1885 damage by snow extended to an altitude 

 of G,560 feet above sea-level. 



No aspect is absolutely safe against snowbreak ; most 

 snow in Central Europe comes from a westerly direction, fi'om 

 which quarter also the strongest winds blow. The south- 

 easterly, easterly and north-easterly aspects, especially just 

 below' the crest of the hills, suffer most; the snow falling 

 most abundantly in such places and l^eing less easily shaken 

 from the trees by the wind, accumulates on their crow'ns. 

 Since, also, freezing winds blow chiefly from the east, a frozen 

 crust is tl^en formed over the snow, on which liiore snow 

 lodges when there is a subsequent snow-storm. North and 

 north-westerly aspects suffer less, and westerly, south-westerly 

 and southerly aspects least of all. Depressions and sheltered 

 spots in valleys are much exposed to snowbreak, as the wind 

 cannot free the crowns of the trees from snow in such places. 



Fertile, deep, moist soil (above granite, basalt, porphyry) 

 favours growth in height, produces brittle coniferous wood, 

 and disposes the trees to breakage. Slowly ^rown short trees, 

 that occur in unfavourable localities, are much less endangered. 

 Too much moisture in the soil is also unfavourable, as the 

 roots have a bad hold on the ground. 



A strong growth of gra^s and herbage is bad in plantations, 

 as the snow presses the weeds on the young plants. 



/. Mode of Formation. 



Under otherwise equal conditions young pole-woods which 

 have grown up in dense thickets suffer most from snow% their 

 scanty root-systems and slender drawn-up stems exposing 

 them to danger. Poles resulting from sowings suffer more 

 than plantations where from the first each individual plant 

 has had sufficient room for its development. Planting two or 

 more plants in each planting spot, termed multiple-planting, 

 is also less favourable where snow is to be feared than planting 

 single plants. 



The distance between the planting-spots is also important, 

 as plants with stronger roots, and crowns, capal)le of resisting 

 the pressure of the .snow, result from wide planting. Such 



