CENTRAL EUROPE 289 



taneous or artificial deterioration of the soil. Again, the 

 interference of man, mostly by cutting or burning forests 

 for mining, smelting, for agriculture, or cattle and sheep 

 raising, has entirely altered the original covering, and 

 resulted in a complete disturbance of the natural state of 

 affairs. Thus different kinds of forest have replaced 

 each other or again have given way to pastures, moors 

 or waste lands. 



Among the predominant forest constituents, the oak 

 and the beech stand foremost and sometimes form nearly 

 pure communities. The beech especially succeeds in 

 shutting out all competitors, much as the spruce does. 

 The oak constitutes more open covers and tolerates the 

 growth of other subordinate trees. The sweet chestnut, 

 the birch, the ash, the hornbeam may also flourish 

 almost exclusively in special circumstances and over 

 tracts of lesser extent than the oak and the beech. 

 Other still less social trees, which occur scattered or in 

 small clumps, are the maple, the aspen, the rowan, elms 

 and lime-trees, the gean (or wild cherry), willows, poplars, 

 &c. The shrubs and smaller trees of the undergrowth are 

 also deciduous. The temperate forests vary greatly in 

 the amount of undergrowth which their leaf canopy 

 allows. The heavier types like the beech forests, 

 when most strongly developed, exclude all underwood 

 except a few mould-loving species, like the lily of the 

 valley, Solomon's seal, herb Paris, certain orchids, wild 

 hyacinths, anenomes, primroses, woodsorrel, woodrush, 

 woodruff, or again ferns and patches of mosses. 

 The clearings generally harbour a large number of 

 shrubs, perennial and annual herbs, and even bulbs 

 and tubers. 



The fairly regular distribution of the rainfall through- 

 out the year, the absence of excessively dry winds, and 



1159.1 • XJ 



