Gleb R. Glazman

The functioning of stationary soil lysimeters is determined by a limited volume of soil in both horizontal and vertical directions. The areal spatial limitation and the proximity of phytocenoses to each other in the large lysimeters at the
Moscow State University Soil Station determines the interbiogeocenotic exchange of plant litter, while the vertical
one excludes the role of groundwater and their influence on soil formation. The absence of lateral runoff, which is
common in natural landscapes, and the increased supply of alkaline earth elements with atmospheric precipitation
and dust, reduces the manifestation of the eluvial-illuvial process. Comparison of lysimetric waters in 1967–1968
and 2014–2015 showed a significant increase over time in the concentration of elements such as calcium, sodium,
magnesium and potassium, and among the anions chloride and sulfate ions. The local spatial geochemical contrast
of lysimetric waters caused by the effect of anti-icing agents, however, does not change the relative migration ability
of elements. According to the level of biogeochemical accumulation of elements in the soil, macroelements form
a series of Ca > K > Al > Mg > Na, and trace elements — Zn > Sr > Cu > Ba, while maintaining the same type on all
types of lysimeters. An increase in the concentration of elements in the soil occurs in the following order: broad
leaf > spruce > mixed > pure fallow. The increased accumulation of elements in the soil profile of spruce forests in
comparison with mixed plantations correlates with the type of humus forming here, which is close to the moder
type, which is due to the combination of coniferous and deciduous litter.

The typology and total reserves of mortmass concentrated in the forest fl oor of the main types of biogeocenoses developing within the stationary bulk lysimeters of the soil station of Lomonosov Moscow State University have been studied. It is shown that mainly destructive floor develops in spruce forests, fermentative floor is formed in mixed stands, while humifi ed floor is formed in broad-leaved stands. An interbiogeocenotic litter exchange has been established, in which foliage is found in spruce biogeocenoses, overgrown fallows and in fallow conditions.
Calculation of floor-litter coeffi cients according to N.I. Bazilevich made it possible to characterize the type of circulation in spruce plantations as inhibited — floor-litter coeffi cient (LOC) 2,8 — , which is due to the predominant participation of needles, resistant to decomposition. In broad-leaved and mixed plantations, an intensive type of
cycling was established with an SAR of 1,2. It has been shown that when calculating the total reserves of organic matter in the litter, the content of mineral impurities should be taken into account, the proportion of which should
be estimated in the course of laboratory studies.

A comparative analysis of the composition of lysimetric waters for 2021–2022 was carried out. for two groups
of stationary soil lysimeters in the city. Th e fi rst group of lysimeters is formed by the system: fallow — grass
phytocenosis — overgrown fallow — spruce forest — mixed and broad-leaved plantation, developing on the
same type of mantle loam. Th e second group of lysimeters represents soils with diff erent types of tillage: conventional
plowing, extra-deep planting according to Bushinsky, plowing according to Mosolov, deep plowing
according to Kachinsky.
For both groups, the same type of migration of components is shown, in which the most migrating elements are
carbon, mono- and divalent cations, and chloride ion, with minimal migration of iron, manganese, and aluminum.
In the group of lysimeters under various types of vegetation, as the tree canopy develops and, accordingly, the
intensity of the biological cycle increases in migrating waters, the concentration of such important biophilic elements
as magnesium, calcium, potassium, and carbon increases signifi cantly, and among anions, chloride and sulfate ions.
Th is determines, within the framework of the cluster analysis, two diff erent subgroups in terms of the composition of
natural waters: the fi rst one is formed by the fallow-grass phytocenosis — overgrown fallow system, and the second
one combines tree plantations.
In the group of lysimeters with diff erent tillage, a cluster characterizes the composition of water in lysimeters with
reclamation plowing according to Mosolov and deep plowing according to Kachinsky. At the same time, individual
aggregates form lysimeters with conventional plowing and ultra-deep planting according to Bushinsky. This is explained
by the fact that in this group of lysimeters, the initially created soil profi le design is transformed, which is
characterized by the placement of eluvial and illuvial soil horizons in various combinations and at diff erent depths
depending on the type of plowing.