CENTRAL EUROPE 291 



Quite apart from spontaneous causes, it is now fairly 

 certain that a large extent of such peat bogs covers the 

 former sites of forests. A considerable portion of the 

 North German heather moors has taken the place of 

 forests of conifers : the manifold varieties of pastures 

 have similarly replaced other vegetable coverings : again 

 cultivation has extended over former timber grounds or 

 natural meadows, or over former swamps. Doubtless 

 the later or secondary developments of the original 

 plant cover and the uses to which it was put by man 

 were largely determined by the double influence of 

 climate and soil , yet even the nature of both has been 

 so profoundly altered in the process of utilization that it 

 becomes increasingly difficult to unravel the tangle of 

 actions and reactions which have been at play. 



Western Europe climatically is distinguished from 

 central Europe by its milder winters, during which frosts 

 are only temporary ; by a somewhat greater and more 

 regularly distributed rainfall ; by cloudier skies, and 

 a moister atmosphere. The vegetative period is thus 

 longer than in central and eastern Europe, while the 

 summer is also somewhat milder than farther east. It 

 is generally a region of subdued features, large plains 

 and gentle uplands, and for these reasons the vegeta- 

 tion lacks the variety which obtains in central Europe. 

 Most of England belongs to this region. It is essentially 

 a land of oak and beech forests and of green pastures 

 and meadows. Conifers are remarkably lacking, except 

 the Scots pine in Britain, the common juniper, and the 

 yew. They have been introduced extensively, but 

 never constitute, in the wild state, pure or mixed forests. 

 The westernmost coniferous forests are to be found on 

 the line of the Venns, the Vosges, Jura, and western 

 Alps, on the central plateau of France, and on the 



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