Forest tracts of the northern and southern belts

FORESTS
World forest resources.



Forest tracts of the northern and southern belts.

The vegetation cover of the Katunsky Ridge was singled out by A.V. Kuminova as an independent Katunsky high-mountainous region,
assigned to the Central Altai high-mountain district. A characteristic feature of the vegetation of the region, striking to every person who first got into the mountains, is a pronounced altitudinal zonality. If you climb the slopes of the Terektinsky ridge and take a look at the northern side of the Katunsky ridge, you can see how the steppe areas of the bottom of the Katun and the lower reaches of the Kochurla and Akkem are replaced higher by densely forested slopes. The dark green color of the forest belt is noticeably different from the light green of the highlands, which outlines the foothills of Belukha crowned with snow. In contrast to the northern, on the southern slope of the ridge, the forest belt is much less pronounced, but the belt of subalpine and alpine meadows is much more widely represented.
On the northern ridge along the valleys of the Kochurly, Akkema and Iedygema rivers, the forest belt in the lower part is represented by birch-larch forest on the cover of chernozem or slightly podzolized soils. Here you can meet, in addition to larch and birch, bird cherry, mountain ash, hawthorn. The undergrowth is represented by meadowsweet, acacia, wild rose. A fairly dense herbaceous cover is formed by all kinds of cereals, irises, sedges, meadow geraniums.
Higher up the slopes the forest becomes thicker. Spruce, fir, cedar appear in its composition, and it takes on the appearance of a dark coniferous mountain draft taiga with an admixture of birch and aspen. In the undergrowth, bushes of honeysuckle, caragana, yellow acacia, deer, meadowsweet, raspberries, and currants are widely developed. This forest kingdom is especially picturesque at the time of fruit ripening in the month of August. Shrubs are usually intertwined with tall taiga grass and difficult to pass. The gloomy fir trees are littered with lichen, a soft moss cover covers the boulders. Birch rises up the slopes up to 1400 - 1500 m, aspen penetrates a little higher, and then only cedar and larch dominate. The higher up the slope, the more space the cedar conquers, and the upper border of the forest is predominantly it.

The marginal cedars and larches usually have a depressed appearance: the cedar crown acquires a flag-like shape when all branches are on the leeward side. Larch, shedding needles for the winter, is better preserved, but, as a rule, is devoid of tops. Sometimes cedar and fir are represented by creeping forms. Individual specimens under the protection of rocks or on well-lit slopes rise 200 - 250 m above the main mass of trees and have a stubby, squat appearance. The border of an adult, dense forest runs on the northern slope, usually at the edge of the moraine ramparts of the 14th - 19th centuries. (Iedygem, Mushtuayry, Konyayry), and above rises young growth of larch and individual birches (in Iedygem). In Akkem, the border of continuous forest does not rise beyond the upper edge of the lake. A similar picture is observed in Ioldoairy, where the forest stops at the edge of the lake. The height of this border is 1960 (Kurkure) - 2100 m (Mushtuayry).

In the depressions of the river valleys, occupied in the past by lakes, high-mountain sedge-cotton grass bogs develop (Kochurla, Akkem). Along the edges, they pass into subalpine swampy meadows.

On the southern slopes, instead of the forest, a forest-meadow-steppe belt is developed. The forest grows here only in areas of sufficient moisture. Usually these are hollows of erosional origin, the northern slopes of small ridges, where snow is blown off in winter and an increased layer of fine earth is formed. Young trees stretch out in a line along the slopes, as can be observed in the Kapchala and Katun valleys.

Significant accumulations of trees are confined to the slopes of the left sides of the B. Berel and Katun valleys. In the Katun valley, the forest ends at the confluence of the Kaptchala, although individual trees grow on the slopes near the glacier at an altitude of 2150 - 2200 m.

The Berel valley is much richer in forest. Here, as in the valleys of Iedigem and Myushtuayra, the forest rises and even covers the moraine ramparts of the 17th - 19th centuries. The southern slopes, free from forests, are occupied by steppe associations, and the most humid slopes are occupied by tall grasses.

In the next alpine zone, near the forest border, large areas are occupied by subalpine shrubs and meadows. On the northern slope, almost to the very glaciers, bushes of squat birch and willow form sometimes impenetrable thickets, as is the case in Konyayri. On the southern slope, the shrub belt corresponds to subalpine tall-grass meadows on soddy-podzolic soils. High, up to 1.5 - 2.5 m, the cover does not sod the soil, and the plants do not adjoin closely to each other, there are no turf plants. In late autumn and early spring, meadow areas are covered with a thick layer of rapidly decaying "old men" ⁴¹⁾ . Tall grass is also common in forests (Berel). The main plants of these meadows are maral root, various-leaved budyak, white-colored geranium, mytnik, Altai light, bluegrass, sorrel, etc. On the rocky slopes you can see gooseberries, currants, and junipers.

Higher up the slopes, the height of the herbage decreases and the subalpine tall grass is replaced by alpine low grass meadows with a sparse herbage. A moss cover is developed on flat moistened areas. On mountain-meadow, often gravelly soils, plants grow brightly flowering with large corollas. The main background of the meadows is given by a flowering catchment area and lights or "hot" flowers. Among the bluish-orange waves of these flowers, there are white anemones, blue snakeheads, golden-yellow buttercups, raspberry hemp, violets. There are especially many such bright lawns in the Berel-Katun interfluve. In addition to flowers, alpine timothy grass, Krylov's fescue, sedges, etc. are widely found.

Above the alpine meadows, the vegetation of the mountain-tundra zone spreads. This strip occupies sections of the slopes slightly above the forest line and reaches the snow line. Small shrubs of herbaceous and netted willow, shrub birch alternate with cottongrass, sedges, rushes and above are replaced by moss-lichen tundra. Finally, the uppermost parts of the slopes, scree, rocks are covered with colorful lichens of black, orange, yellow and other colors. Lichens are so densely embedded in the rocks that they can be separated only with fragments of the latter.
Conifers
Forests formed by B. mandshurica and B. platyphylla are usually grouped under the name "white birch forests". Indigenous white birch trees form small scattered forests among meadows and swamps in the wide lower parts of the valleys of the right tributaries of the river. Ussuri and on the ancient lake terraces of the Khanka Plain.
Most of the mountain white birch forests are secondary forests formed on the site of burnt or cut down coniferous and broad-leaved-coniferous forests. In the altitudinal zone of fir-spruce forests, on slopes of different exposure and steepness, grassy types of white birch forests of III-IV quality classes are formed. In the zone of broad-leaved-coniferous forests on relatively gentle slopes of predominantly southern exposures, white birch forests with an undergrowth of Corylus spp., with a productivity of I-II class of bonitet, predominate. On the slopes of the northern directions, white birch forests are more often formed with the participation of coniferous and broad-leaved species, which indicates a greater short-term existence of their existence compared to other white birch forests. Betula costata is a component of many types of fir-spruce and broad-leaved-cedar forests. During the periods of extinction of the older generations of Picea ajanensis and Pinus koraiensis in the stands of different ages in these forests, B. costata temporarily dominates. The period of its dominance can last 25-30 years or more. Such "yellow birch forests", as they are often called, are only one of the stages of the age development of spruce and cedar forests. But in most cases, yellow birch forests are secondary forests formed after logging, less often after fires, in mixed forests with a predominance of conifers. In recent decades, the areas of yellow birch forests have increased significantly precisely for this reason. Forests with a predominance of B.