In the past 5000 years, there can be distinguished three natural vegetation zones in Eurasia and the Mediterranean. These were not always in exactly the same place: climatic fluctuations led to temporary changes in the exact location of these zones. Thus, the limit of viticulture was situated further north than in the recent past during the aforementioned warm interval between 450 BC and 700 AD. But the general picture has remained quite stable for five millennia, until present-day global warming has set things moving. It should be stressed that we are talking of natural vegetation: this natural vegetation cover has in many places been largely or completely replaced by crops and pasturage, or otherwise destroyed by human interference. This profound alteration of the landscape had already started in the ancient world.
The first zone, to the north of the limit for viticulture (around 40 degrees north latitude, in Europe only 50 degrees) has, from north to south, tundra, boreal coniferous forests (taiga), mixed forests and deciduous broadleaf forests, steppe and (semi-)desert, and at the higher altitudes, specific mountainous vegetation. Northern, western, and central Europe are mainly forest areas, except for a bit of tundra in the extreme north. The climate here is humid, from the sub-Arctic climes in the north, by way of the marine climes of the west to the continental climes of the center. Central Asia has extensive steppe areas, stretching all the way from Hungary in the west to Manchuria in the east; toward the north, this shades into desert, which in its turn gives way to taiga and Arctic tundra. In the south of this area, the climate is cold and (semi-)arid, and in the north it is sub-Arctic: humid with long, severe winters. Eastern Siberia and northeastern China form an intermediate zone with mixed forests and broadleaf forests: they have a humid continental climate with cold winters and warm summers.
The second zone lies between the limits of viticulture and the Tropic of Cancer (at 23.5 degrees north latitude) and is characterized by Mediterranean vegetation, steppe, desert, and mountainous vegetation. Southern Europe and northern Africa have a specific Mediterranean climate: warm dry summers and mild humid winters. The typical Mediterranean vegetation, with evergreen broadleaf trees and shrubs as the most conspicuous feature, is found all around the Mediterranean, although in parts of northern Africa the desert nowadays reaches the sea. The desertification of the Sahara region is a comparatively recent phenomenon: northern Africa started drying out from about 5000 BC, but only in the third millennium did traffic across the Sahara begin to be impeded by the desert. Slowly, but surely, northern Africa became isolated from sub-Saharan Africa. Ever since, the desert has been encroaching. Egypt, the Near East, and the Arabic peninsula are largely desert and steppe, and have a desert climate. Only the river valleys of the Nile, Euphrates, and Tigris, and a number of oases are the exceptions: alluvial instead of desert soils and plenty of water. From Anatolia in the west to the Punjab in the east stretch mountain ranges and upland plateaus, with steppe and desert vegetation, and again mountain vegetation on the higher slopes. Further to the east we find the mountains of Afghanistan and the Himalayas. The climate varies from a warm and dry continental one to a tundra climate in most ofthe Himalayas. In China, the north consists of plains and regions with loess soils, with a steppe or desert vegetation and a climate to match. The south is mountainous, with forest cover, and a humid and warm subtropical climate.
The third zone to the south of the Tropic of Cancer is characterized by subtropical and tropical vegetation. The main landmass is the Indian subcontinent, with the alluvial plains of the Indus, Ganges, and Brahmaputra, and to the south plains and uplands. The annual rainfall increases from west to east, with the exception of the western rim of the subcontinent. The vegetation varies from desert immediately to the east of the Indus to tropical monsoon forests in the delta of the Ganges. The southern subcontinent has tropical rainforests on its west coast and in Sri Lanka; otherwise, there is dry tropical forest and savannah. The climate also runs the gamut from desert to tropical. Southeast Asia is an area with mainly tropical rainforest and monsoon forests. The climate there is tropical, except for the subtropical north.
World History
