Few people remember from the school curriculum what altitudinal zoning is. This concept describes the change in the upward movement of weather characteristics, landforming processes, rocky soil composition, as well as flora and fauna. But due to a number of reasons, such as inaccurate information about each individual component, the altitudinal zonality of the landscape is characterized by the most accurately measured parameters: climatic and geomorphological.
Vegetation and other components forming altitudinal zonation
Although vegetation (with all its dynamic constancy and division by habitat) does not in all cases show the state of the modern total barrier for a large number of factors, do not belittle its importance in forming an idea of what altitudinal zonation is.
For this reason, the conditional combination of vegetation habitats at different elevations of the relief is considered permissible and regular. According to the characteristics of the components - vegetation, soil composition, climate, wildlife, ecosystems in general, the landscape can be divided into zones of altitudinal zonation. For various mountain systems, they are quite different. In particular, the altitudinal zonation of the Ural Mountains will differ from the altitudinal zoning of Tibet. In order to correctly and reliably divide the landscape into zones, it is necessary to highlight a common variable characteristic.
Reasons for high altitude
Compared with the plains, in the mountains, the diversity of species is much higher - 2-5 times. But what is the cause of the "multi-storey" nature zones in the highlands?
The main factors are the height of the mountains and their geographical location. Natural areas change in much the same way as when moving across the plain from south to north. However, when moving up the mountainous terrain, this change is more noticeable and it occurs at relatively low altitudes.
Altitudinal zones are present in the greatest number in tropical latitudes. In the band of the Arctic Circle at mountains of the same height, the smallest number of such zones.
Climate in the mountains
Altitudinal zonation in the mountains is inextricably linked with climate. All altitude zones cover the mountains on each side, however, the tiers on the opposite slopes are completely different. At the foot of the mountains, the climate is more like the weather conditions of the adjacent plains. Higher are tiers with more moderate, and then quite severe weather. At the top is the permafrost and snow zone. And, it seems, the closer to the Sun, the warmer, in theory, but in reality this is not so.
Although exceptions also occur. This proves that the zone of altitudinal zonation is not an isolated phenomenon, and it depends on many factors. In Siberia, there are places where the foothills of the climate are harsher than on the slopes of the mountains. This is due to the lack of air circulation in the hollows between the mountains.
What characterizes the altitudinal zonality of Eurasia?
The closer the mountains to the south, the greater the number and variety of altitude zones. Ural is one of the most significant mountain systems.
In the southern part, the altitudinal zonality of the Ural Mountains has more tiers than in the northern, despite the fact that the southern mountains are lower. In the northern part, only the mountain-tundra belt is present.
The Black Sea coast of the Caucasus and the Amuro-Sakhalin region
The contrast of the belts on the Black Sea coast of the Caucasus is even more pronounced. In just an hour by car, you can go from the subtropical coast of Sochi to the subalpine climate of the Western Caucasus.
In the Amuro-Sakhalin Oblast, all the provinces share the same attribute - the structure of landscape bands. They are divided into:
- mountain tundra;
- Podgoltsovaya - overgrown with cedar forests, rare forests of Ayan spruce, as well as stone birch of varying degrees of concentration.
In South Sikhote-Alin, there are all characteristics typical of the Amur high-altitude zone.
Among the tiers, the following are distinguished: low-mountainous strip (cedar forests with wide leaves, as well as the soils and climate formed by them), mid-mountainous strip (forests of dark coniferous trees and the corresponding underlying surface), subalpine strip (a mixture of dark-coniferous forests, dense copepods of cedar shale, groves stone birch), the loach strip itself, which is the tundra in its purest form.
If the climate becomes more continental, then deciduous forests are added to such a scheme. In the western mountains of Southern Sikhote-Alin, there is a belt of mountain tundra, a strip of subalpine shrubs (or creeping mountain forests), a strip of stony birch forests, a fir-spruce forest belt (spruce forests), a belt of broad-leaved cedar forests (cedar forests), a belt of broad-leaved forest and.
Dependence of the border of the forest and the height of the mountain
To date, a considerable amount of data has accumulated on how high the upper line of the forest strip is in South Sikhote Alin. The amplitude of heights created by the upper boundary of the forest at certain peaks and slopes of the same ridge takes on quite large values and reaches more than 300 meters vertically.
The general tendency is clearly noticeable: with an increase in the height of the peak, the upper border of the forest also shifts upward (effect of the height of the massif). However, although the mountain ranges are located far from the sea at a distance of 15 to 105 kilometers, the proportion between the height of the upper border of the forest and the peak is almost the same for each slope. This result is not very logical and expected, and, therefore, needs to be explained.
Alogicity is manifested in the fact that this proportion refutes the assertion that the sea has a great influence on the position of the upper border of the forest. To be more precise, within the boundaries of South Sikhote-Alin, the influence of the sea is felt in the upper zones with approximately the same strength. That is, the altitudinal zonality of Eurasia does not so much depend on the presence of the seas.
Otherwise, such proportions for mountain peaks in coastal latitudes (Hualaza-Litovka, Pidan-Livadia, Tavayza-Brusnichnaya) should not be so large. This affects the height of the ridge itself on the position of the upper forest boundary. In accordance with this characteristic, only Cloud Mountain is distinguished, the highest peak of South Sikhote Alin.
There are two ways to explain this phenomenon: either the massif in this place is so high that the temperature threshold determining the upper border of the forest reaches a maximum height in the region, or the vegetation brought out of equilibrium with the climate has not yet adapted to it. The constituent parts of the altitudinal zonality inherent in Mount Brusnichnaya are also characteristic of the peaks of the coastal part and the Southern and Middle Sikhote-Alin, which is noticeable in the forests of alpine oak forests.
