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Information about the effect of wetting regime on the composition of the flora of the Verkhoyansk Ridge (Yakutia) is presented. The regularities of changes in ecomorph structure in connection with latitudinal zoning and vertical belt sequence of the mountain system under consideration are analyzed.

Results of the investigation of postfire succession dynamics in light-coniferous – small-leaved forests in the Prienisey part of the Eastern Sayan on the landscape-ecological basis are presented. A generalizing scheme of the directions and rates of succession interchanges taking into account the pyrogenic factor was built and analyzed.

Data of the experimental investigation of postfire digression of the subtaiga – forest-steppe pine forests in the South-Western Pribaikalia are analyzed. It was established that the surface fire of forest floor – humus type are the major destructive factor in the dynamics of pine forests. The action of the surface fire is accompanied by tree dryout, while the vitality of the trees that survived in fire depends on the severity of fire damage. Characterization of the lower plant storeys and its dynamics under the effect of middle-intensity fire events are presented. A negative effect of surface fire on the changes of the stand, qualitative fractional composition of organogenic soil horizons and their chemical composition was demonstrated.

The phytocenotic role of separate Gmelin larch trees that survived on burns after fire was shown for the conditions of cryolitozone of Middle Siberia. Depending on the vital state of the trees, the boundaries of their effect on the recovery of species composition of the lower storeys of phytocenoses and the formation of a new generation of tree stand were determined.

Ecological structure of flora burnt depends on climatic conditions and geographic location. The secondary post-fire succession in lowland pine forests occurs rather rapidly, and after ten years the burns are at the stage of the formation of communities of patient plants. Pyrophyte plants become important in the formation of vegetation in burns. Formation of zonal vegetation types does not occur in ten years. A reduction of periods between fires leads to the fact that plant communities in flat pine forests are under constant influence of the pyrogenic factor.

Pyrogenic changes of microelement content in soil and plants of the pine forests of West Transbaikalia (Republic of Buryatia) were studied. It was established that surface fires under the studied conditions cause changes of soil properties, insignificant increase in the concentrations of Mn, Zn, Cu, Pb in the upper layers of soil (0–40 cm) and Mn, Zn, Pb in plants. It was revealed that the ratio Fe : Mn in soil gets narrower. Investigations show that the pyrogenic change of vegetation and soil properties, in particular elemental composition, is observed during several years after the fire.

The data on the variability of the structure of plant communities formed under the conditions of the steppe extrazonality of the Barguzin basin (North-Western Pribaikalye) are represented. Geobotanic and soil profiles for one of the most significant study areas were made. The structure of contact communities of the light-coniferous taiga and extrazonal steppe was revealed. The edaphic conditions and location of plant communities reflected the direction of vegetation cover developing in this part of Pribaikalia.

Soil samples from natural forests and adjacent farmland were analyzed to investigate the dynamics of soil organic matter of red soil in Southern, China. Based on the δ¹³C values and the content of soil organic matter, the data indicated that the turnover of soil organic matter under the virgin forest was slower than that under cultivation. Soil organic matter is fresh in coarse sand and oldest in fine silt and clay. Also, the soil light fraction contained the younger organic matter than soil heavy fraction and bulk soil. Deforestation has accelerated the decomposition rate of soil organic matter and reduced the proportion of active components in SOM and thus soil fertility.

The hygroscopic properties of forest floor in coniferous (Larix sibirica Ledeb., Pinus sylvestris L.) and deciduous (Populus tremula L., Betula fruticosa Pall.) plantations were studied using the isotherms of water vapor sorption and methods of thermal analysis (TG, DSC). Sub-horizons OL and OF in larch and pine plantations had the larger monolayer adsorption capacity. The forest floor in larch plantation was characterized by the highest hydrophilicity. Results of DSC indicated that hygroscopic water had higher binding with the substance of sub-horizon OL in coniferous and sub-horizon OH in deciduous plantations. The forest floor in coniferous plantations was characterized by higher store of hygroscopic water than in deciduous ones.

Investigation of the enzymatic activity of modern and lower gorizont of soils of the islands and the near-bench floodplain of the Lobanovskaya branch at the right bank of the Selenga delta is described. Ecological conditions determining its differences at the regions under study are conditions. Evaluation of the activity of enzymes in the soils of the right bank part of the delta in comparison with the regions of the left-bank part differing in the landscape ecological parameters is presented.