86 PROTECTION AGAINST MAN. 



the following ways : by the animals browsing on young plants ; 

 biting-off buds, leaves, and shoots ; brealdng-off coppice-shoots 

 and gnawing the bark of trees ; trampling on, bending down 

 and breaking young growth ; exposing and destroying roots, 

 etc. The damage done by biting the plants is twofold ; they 

 lose organs that are necessary for their nourishment, while the 

 normal development of their stems and branches is prevented. 

 Both forms of injury occur chiefly in their youth, until 

 their leading shoots have grown beyond the reach of the 

 animals. 



Eoads, ditches, slopes, hedges, and fences, are especially 

 liable to injury by grazing animals. 



The extent of the damage done by grazing depends on a 

 number of factors. Among the chief of these are : Species 

 of tree, age of tree ; system of management, nature of locality, 

 density of crop, species of grazing animal, number of animals, 

 season of the year, state of the weather. The amount of 

 damage varies greatly according to circumstances. Hundes- 

 hagen* estimates the ordinary loss of increment due to cattle- 

 grazing at one-tenth. In Carinthia it has been observed that 

 goats in 16- to 35-years-old spruce, Scotch pines and hornbeams 

 prevent almost any growth from taking place. 



(2) According to Species of Tree. 



Broadleaved species are more exposed than conifers, but 

 recover more readily from browsing than the latter. Most 

 exposed to damage are : ash, maples, hornbeam, beech. Next 

 to them : lime, sallow, and poplars. Less still : oaks, elms, 

 Pyrus sp. Least of all : birch, alder, horse-chestnut and 

 robmia. 



Of conifers, the silver-fir suffers most, then larch, the 

 different species of pine and the spruce. If the spruce 

 appears to suffer more than pines, this is due to its abundance 

 in mountain regions, where there is most forest pasture. 



The above scale is drawn up chiefly as regards horned 

 cattle, but if we consider the preferences shown by other 



* " Encyclopadie der Forstwissenschaft." I. Forstliche Productionslehre, 3 

 Aufl. Tubingen, 1835, p. 512. 



