22 BRITISH PLANTS 



beyond them. In the vertical direction this type of 

 vegetation characterizes the higher altitudes in moun- 

 tainous regions everywhere in Europe. The particular 

 kind of tree dominant anywhere natm'ally varies. The 

 Scots Pine, Pinus sylvestris, likes room and sun, the 

 Norway Spruce, Picea excelsa, prefers shade. The Silver 

 Fir, Abies pectinata, forms vast and stately forests in the 

 ancient highlands of Southern Germany; while the 

 Mountain Pine, Pinus montana, inhabits the high barren 

 slopes of the Pyrenees and French Alps. The Stone Pine, 

 Pinus Pinea, is common in the Mediterranean, where it 

 suppresses the holm-oak, Quercus Ilex, on high, moderately 

 weathered slopes. The leaves of conifers contain resin 

 and rot with difficulty. This combined with a cold soil, 

 in which there is a deficiency of nitrifying bacteria, makes 

 it ill-suited for cultivation. The region is sparsely 

 populated. 



3. Deciduous Forests (e.g., oak, beech, birch, ash, etc.). — 

 These trees lose their leaves in winter. They require 

 more moisture and warmth than conifers, and therefore 

 have their greatest extension in Western Europe. The 

 leaves decay quickly and as they all fall every year a deep 

 fertile soil is gradually formed which can be efficiently 

 cultivated when the trees are cleared away. The greater 

 part of the lowlands of Germany, Prance, and Great 

 Britain was once covered with deciduous forests. In 

 Germany much of these still remains, but in England 

 only fragments of the original forests survive. With the 

 growth of settled populations these forests have fallen 

 a sacrifice to the needs of civilization, providing timber 

 for the builder, fuel for the smelter of iron, and ground 

 for the tiUer of the soil. 



4. Grassland. — This is characteristic of the continental 

 type of climate with wide extremes of temperature. The 

 rainfall, though too scanty for trees, is fairly uniform, 

 most falling in spring and early summer, that is, in the 

 growing season when the vegetation needs it most. The 

 largest grasslands in Europe are found in Russia and 

 Hungary. The Ukrainian Steppes lie between Poland 

 and the Black Sea. These are covered with a fine sandy 

 humus-laden soil, called loess, an air-borne deposit which 

 owes its origin to the Ice Age. Upon the ice-sheets, 

 which at this period covered Northern Europe, lay a 



