557 



CHAPTEE V. 



PROTECTION AGAINST HAIL.* 



1. Damage done. 

 A. General Account. 



HAIL completely beats down young plants, and injures sap- 

 lings, poles and young trees by breaking off leaves, blossom, 

 fruits, young twigs, and leading shoots, and by stripping off 

 flakes of bark, either in little patches or short strips, and thus 

 exposing the cambium-zone. The marks of the wounds made 

 by hail in the bark of trees are often noticeable for a long 

 time, the amount of damage done depending on the size of the 

 hailstones. 



Birds, and game such as hares and roes, may be killed by 

 large hailstones. The greater the size of the latter the greater 

 the damage done. 



The direct consequences of damage by hail are : loss of incre- 

 ment, disease, deformed growth, decreased production of seed, 

 and even death of young plants and poles. 



The indirect damage consists in insect attack and the admis- 

 sion through the wounds made by hail of spores of species of 

 Nectria and other fungi. 



B. Damage under Special Conditions. 



Conifers suffer most from hail, especially the Scots, Austrian 

 and Weymouth pines, the spruce and silver-fir somewhat less ; 

 the larch soon recovers from injuries to its shoots or barjk. 



Among broadleaved species, those with less power of 

 occluding wounds, and with thin bark, such as the beech, 

 suffer most, but the oak, robinia and other trees when young 



* Riniker, Hans: "Die Hageschlage in Kanton Aargau." Berlin, 1881. 

 " Mittheilungen des Vernischen Statistischen Bureaux." Bern, 1885, 1886. 

 " Die hagelschlage seit," 1878. 



