Geographical distribution of cedar-trees
Among the stone pine forests described by us, the most widespread are associations with greater or lesser participation of fir. Such mixed stands are typical for the central in our district association of the cedar forest bilberry-green. The second largest group of associations in the landscape is the stone pine forests. In the humid Pribaikalsky region, they are widely distributed, from the Baikal level to the upper boundary of the stone pine forests, and are also characterized by the participation of fir in the stands. Kedrovniki-bilberries, in which the admixture of fir is small or not, occupy drier locations and are not widely distributed in the Shumilikhi area. They are more widely developed in the wide valleys of the rivers of the Barguzinsky range with terraces composed of washed moraine deposits. Kedrovniki, embodying the power and uniqueness, with a layer of cedar elfin are widely distributed in the upper part of the forest belt, forming a number of high-altitude replacement associations.
From the comparison of our data with the literature on cedar forests, some regularities in the geographical distribution of the associations examined by us are revealed.
In areas with a fairly humid climate on locations equally favorable for cedar and fir, the latter usually forms a more or less closed II stage in the cedar forests, and the juvenile tier predominates over the cedar, as, for example, it is observed in the described section of the northeastern coast of Lake Baikal. In such areas the blueberry-green pine forests are central and have a landscape significance. In the Baikal area, they are confined to medium-moist locations with sufficiently developed weakly podzolized loamy soils that show no signs of swamping. In the northeastern province of the Eastern Saya, in the tempo-conchal belt of the middle reaches, the largest areas are occupied by cedar forests of bilberry-greenish with fir-tree admixture on mountain sod-forest podzolic soils. In more continental areas, blueberry cedar forests are small and inferior to the leading stone pine cowberries occupying central mid-humid locations. The ecological area of the cedar forests is shifted to more moist positions with noticeable signs of swamping. The admixture of fir in them is insignificant or completely absent. The researchers who give descriptions of the cedar pine forests for the continental margins of their range indicate that there is a noticeable participation in their cover of the cuckoo's flax and sphagnum mosses, sometimes the rosemary, blueberry, or the signs of waterlogging in the soil. The somewhat excess soil moisture apparently compensates in part for the insufficient moisture content Air.
Badanic stone pine forests in the humid Baikal region were observed by us in a mixed dark coniferous and light coniferous belt and in the lower part of the dark coniferous to the vertical limit of the distribution of cedar forests. Above they are replaced by blueberry-badan fir-nuts. Badan stone pine forests are everywhere associated with stony, but rather humid soils. They differ best on boulder-loamy morainic deposits and on aboriginal slopes, although steep, but covered with a fairly thick layer of stony-gravelly-loamy eluvio-deluvium. In the Western Sayan, where there is a lot of precipitation, stone pine forests with badan also occur throughout the forest belt, reaching the upper boundary of the forest. In more continental areas, they are described only for the upper part of the forest belt, characterized by high air humidity, and are associated there with the most exposed rocky locations, often with outcrops of the bedrock.
I. F. Novoseltseva and A. II. Utkin believe that the rare lowland cedar forests in the western part of the mountains of Southern Siberia are edaphically conditioned formations and their gravitation toward steep slopes is associated with a greater atmospheric moisture than in the eastern sector of Southern Siberia. The rarity of the Badan's stone pine forests in Mongolia is due to climatic conditions near the southern limit of the cedar. In the opinion of these authors, badan stone pine forests, most likely, have a secondary origin, developing after fires due to the washing away of fine earth from the slopes. VA Povarnitsyn believes that the Badan subalpine cedar forest represents the first stage of settling the cedar on placers.
In areas with the most severe continental climatic conditions and cold soils, where the cedar is still widespread, the stone pine forests of the "Ledum series" predominate. We observed such stone pine forests south of Sosnovka bay in those places where the slopes of the Barguzinsky ridge steeply descend to Lake Baikal, leaving only a narrow strip of plumes and stretches of terraces exposed to temperature inversion on the shore. In the ledum cedarwood on the trail we were found at a shallow depth in the soil of permafrost. With an even greater aggravation of the severity of the climate, predominance passes to the larch forests of the "Ledgel series." The latter are described by us on the eastern coast of the northern Baikal between the rivers Sosnovka and Shangnanda.