TYPES OF VEGETATION 23 



4. Grassland (steppes or prairies). This is charac- 

 teristic of the continental type of climate, where the air 

 is dry, and wide extremes of temperature occur. In 

 winter the steppes are swept with storms of wind and 

 snow ; in spring, when the snow has melted and the soil 

 is moist, a rich mantle of grass spreads over the plains, 

 but in summer this is all dried up, and the steppes become 

 dusty wildernesses. In the damper parts the grassland 

 passes into deciduous woodland, park-land representing 

 an intermediate stage in the transition. 



5. The Mediterranean Region. This is a dry sunny 

 subtropical region in which most rain falls in winter. 

 The winters are mild, and, except on the uplands, frost 

 is almost unknown. Through the dryness of the atmo- 

 sphere, the summers are very hot, but the nights, if clear, 

 are cold. Forests are few, except in the mountainous 

 districts, where, by reason of the greater rainfall, deciduous 

 forests occur (e.g., chestnuts). The characteristic vegeta- 

 tion of the lowland is evergreen e.g., the evergreen oak, 

 orange, olive, arbutus, laurel, and myrtle. One palm 

 Chamcerops humilis reaches as far as Europe, where 

 it occurs on the Riviera. 



[6. Tropical Rain-Forests. These do not occur in 

 Europe, but they form a remarkable feature of the 

 wettest parts of the Tropics. There is no interruption 

 of the vegetation by cold, and the heat is intense, especi- 

 ally at midday. The rainfall is very great at least 

 70 inches annually and this, in conjunction with the 

 great heat, encourages a development of the vegetation 

 which is unparalleled in other parts of the world e.g., 

 the evergreen rain-forests of the Amazon, the West 

 Coast of Africa, the Congo, and the Malay.] 



