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Further development of the asymptotic line wing theory is presented where the long-wave approximation for the molecular centers of mass is violated. This provides long molecular trajectories going far beyond an elementary volume in the case of the nonresonance light absorption. The occurrence of long trajectories is evidence of a certain degree of ordering of molecular chaos. The latter can be described by means of a modified semiclassical representation method to establish correlation between displacement and velocity operators. An expression for the absorption coefficient is derived that allows an ambiguity concerning the estimation of the parameters of the potentials to be avoided and the temperature dependence of the absorption coefficient in line wings to be described. The calculations under consideration employ a diffusion model for H₂O absorption in the 3-5 mm window region and for CO₂ absorption in the 4.3 mm band wing to describe the temperature dependence of the absorption coefficient. It is shown that long molecular trajectories significant for the 8-12 and 3-5 mm H₂O window regions can hardly play a role in the 4.3 mm CO₂ band wing.

D₂О absorption spectrum were recorded between 10000 and 11400 cm^-1 by a Fourier transform spectrometer with a spectral resolution of 0.05 cm^-1. A multipass White’s-type cell was used for spectrum measurements, the optical path length was 40 m. A light emitting diode, which provides more brightness in comparison with other radiation sources, was used as a radiation source. Signal to noise ratios of 10⁴ was obtained. During the D₂О spectrum treatment, the experimental line list contained about 100 lines of the n₁ + 3n₃ band was created. Spectroscopic parameters (line positions, intensities, and half widths) were obtained by fitting experimental data to the Voigt line profiles with using least squares method. The analysis of the spectrum allowed us to derive new energy levels belonging to rovibrational state (103).

The absorption spectra of water vapor perturbed by Ar pressure have been investigated in the wavenumber range 6700-7650 cm^-1. Room temperature spectra of water vapor have been measured by the Bruker IFS 125HR Fourier transform spectrometer with a high signal-to-noise ratio in a wide range of pressure of argon with a spectral resolution of 0.01 cm^-1. The fittings with Voigt and speed-dependent Voigt profiles were performed to retrieve the H₂O spectral lines parameters. It was shown that the use of the speed-dependent Voigt profile gives the best agreement with experimental data.

Studies of spatial-temporal variability of the upper boundary of the forest on the north-western coast of Lake Baikal (Baikal and Upper Angara Ridges) are performed on the base of the analysis of forests renewal processes and of the dynamics of larch radial increment in the ecotone of the forest upper boundary and out of it. The presence of a large amount of well-developed uplands and circuses with considerable heights drops in the structure of mountain system favours formation of interrupted boundary between forest and subgoltsy belt. The timber stand of the upper forest boundary in the studied area is represented by Daurian larch. Three tree-ring chronologies of larch are obtained. The longest chronology is obtained for mountain taiga belt of Baikal Ridge and is as long as 460 years. Since 1980ies, a sustainable trend of increase of radial trees growth is observed. It is observed the most distinctly in trees of the upper forest boundary on the Baikal Ridge. There is advancing of trees species into subgoltsy belt and into mountain tundra, which depends, respectively, on slopes heights, exposition and tilting, on sites of growth of concrete cenoses. Modern peculiarity of the vegetation of the studied area is presence of abundant viable larch undergrowth (from 2-3 to 25 y.o.) and fir in the ecotone of upper forest boundary and in subgoltsy belt, as well as appearing of single specimens of spruce. Main undergrowth mass (2/3) is presented by trees aged in average 15-25 y.o., i.e., they appeared in late 1980ies. Due to increase of snow cover thickness in winter, the trees young growth obtained great protection from freezing resulting in the increase of ability of young growth to live up to elder age.

It is proposed to analyze the stands’ condition to use the method of tendencies, which occupies an intermediate position between a static evaluation of the life conditions and the dynamic assessment of the condition. The trends take into account the totality of the factors, affecting the condition of the trees. The basis for the method is the analysis of tree distribution by the categories of condition. This approach allowed us to identify a set of factors affecting the condition of the trees, depending on the growth conditions of soil and tree species. Siberian larch is characterized by healthy condition, regardless of the method of planting, density, number of rows and soil conditions. This situation can be explained by shelterbelts’ age not exceeding 20 years. At older ages, the soil conditions influence field-protecting forest belts. The best conditions are formed in the stands on the southern chernozems of pure composition, with a row and chess-type of planting. In clean multi-row pine stands, the trees are more healthy condition, compared to mixed stands. The living condition of birch stands is weakened. Favorable conditions found in pure Siberian elm stands with a 3-row and chess-type planting, compared to mixed stands. Relatively favorable conditions for the growth of black poplar trees were observed in pure 4-row stands, growing on ordinary chernozems. Point scale assessment of the stands shows that healthy state have larch belts in the steppe of Shira lake. Field-protecting shelter belts in the Republics of Khakassia and Tyva, with some exceptions, are in weakened and badly weakened condition. In those stands conducting agronomic and silvicultural treatments to improve mineral nutrition and moisture supply is the urgent need.

In 2007-2014 on the permanent sample plot (PSP) in Krasnoyarsk suburban young pine forest (forest-steppe zone of Central Siberia), annual inventory characteristics were estimated. PSP area was 0.024 ha. In 2007 the average age of pine young forest was 7 years; 413 trees with height more than 1.3 m, including 412 living trees and 1 dead tree were measured. Since 2007 the parameters of each tree were measured every year. The diameter at the height of 1.3 m (D_1,3), the tree height (H), the category of vital state (by a 6-grade scale of the Forest Health Regulation of the Russian Federation) were determined. The stem volume (V) of each tree was estimated using regression equation including the variables: V, D_1,3, H . Parameters of the equation were calculated by sample trees, measured in 2007 and 2014. The timber stock was determined as the sum of stem volumes of the separate trees. At early stage of pine tree stand formation, the form factor ( f ) in young pine growth exceeded 1. During 2007-2014 average diameter increased from 1.8 to 5.3 cm, average height - from 2.3 to 6.2 m, timber stock of the growing trees - from 16 to 128 m³/ha, dead timber stock of the dead trees - from 0 to 1 m³/ha. In 2007 density of more than 17 thousand trees per ha was registered. The maximum density of more than 18 thousand trees per ha was registered in 2009. In the next years, this indicator monotonically decreased. In 2014 density was less than 15 thousand trees per ha. The increase in density is due to increase in the number of trees, with height more than 1.3 m, the decrease - by phytocoenotic stress and felling. In 2007 the category of the tree stand vital state was near 1. In 2014 the category was 1.3. Condition of the young pine tree stand naturally regenerated at arable land after ground fire might be estimated as very good. This young stand is prospective to form high-density pine forest in the absence of creeping fires.

The analysis of age dynamics of average diameters of deciduous tree stands of different forest types at Highland Khamar-Daban (natural woodland in South-East Baikal Lake region) has been done. The aggregate data of average tree, the analysis of age dynamics of average diameters of a deciduous tree stands of stand diameters by age classes, as well as tree stand current periodic and overall average increment are presented and discussed in the paper. Forest management appraisal is done. The most representative forest types have been selected to be analyzed. There were nine of them including three Siberian stone pine Pinus sibirica Du Tour stands, three Siberian fir Abies sibirica Ledeb. stands, one Siberian spruce Picea obovata Ledeb. stand, and two dwarf Siberian pine Pinus pumila (Pallas) Regel stands. The whole high-altitude range of mountain taiga has been evaluated. Mathematical and statistic indicators have been calculated for every forest type. Stone pine stands are the largest. Dynamics of mean diameters of forest stands have been examined by dominant species for every forest type. Quite a number of interesting facts have been elicited. Generally, all species have maximal values of periodic annual increment that is typical for young stands, but further decrease of increment is going on differently and connects to the different lifetime of wood species. It is curious that annual increment of the dwarf Siberian pine stands almost does not decrease with aging. As for mean annual increment, it is more stable than periodic annual increment. From the fifth age class (age of stand approaching maturity) mean annual increment of cedar stands varies from 0.20 to 0.24 cm per year; from 0.12-0.15 to 0.18-0.21 cm per year - in fir stands; from 0.18 to 0.24 cm per year - in spruce stands; and from 0.02-0.03 to 0.05-0.06 cm per year - in draft pine stands. Mean annual increment of dwarf Siberian pine increases with aging and increment of other species holds up almost the same, but decreases slightly with aging.

In June and July 2010 in Yaroslavl, Vologda and Kostroma regions, as a result of exposure to hurricane winds, recorded several violations of extensive forest cover in the form of windfalls and windbreaks (Krylov et al., 2012; Petukhov, Nemchinova, 2014). Retrospective analysis on the basis of remote sensing data for the period 1984-2011’s was conducted. It showed, that among the 21st dedicated mass windfall within the Kostroma region and border areas, windfall July 2010 is unique in the magnitude of the total area of disturbed forest cover. According to our estimates, derived from the analysis of remote sensing (RS), its area was more than 60 thousand Ha, which is four times the average annual area of clear felling, in particular, in the Kostroma region (Petukhov, Nemchinova, 2014). In addition to determining the areas of windfall violations of forest cover, based on forest inventory data and remote sensing data analyzed taxation characteristics of forest stands affected by the impact of the seven gale-force winds within the territory of the Kostroma region. The analysis revealed the following trends in hurricane-force winds damaged trees: for parameters such as completeness, forest type and site class is observed relatively uniform stands hurricane wind damage; I.e., we have not found an association between the degree (probability) of forest stands damaged data and taxation values data. An exception is the age, height, and in some cases, the predominant species plantations. Plantations dominated by spruce in the stand proved to be somewhat less, but with a predominance of pine - more resistant to hurricane winds, compared to other tree species. Selectivity is also observed for breach of stands older than 40 years and a height of over 16 meters, which is possibly related to the morphological and physiological features of the trees of a given age and height.

The paper presents the validation results of the InSAR method for determining the forest canopy height, based on TanDEM-X and ALOS PALSAR data. The research conducted on the territory of the Baikal-Kudara forest area of the Republic of Buryatia (52°10'N, 106°48'E). Forest vegetation is represented mainly by conifers - pine, and spruce, with a small admixture of deciduous trees - aspen, birch, etc. The forest vegetation height was determined by subtracting the digital elevation model (DEM) of the digital terrain model (DTM). DEM is built according to the L-band (wavelength of 23.5 cm) ALOS PALSAR satellite with horizontal co-polarization mode. In the investigation it was assumed that a radar signal of ALOS PALSAR passes all forest thickness and reflected from the underlying surface, made it possible to recover terrain under forest canopy. DTM has been built using the TanDEM-X data (wavelength 3 cm). In this case, it was assumed that the radar echoes scattered from a some virtual phase centers of scattering surface, which characterizes the upper limit of the continuous forest canopy. To check the accuracy of satellite definitions of forest height in study area were made high-precision geodetic measurement of trees heights using electronic total station and the coordinates of geographic control points using differential GPS receivers. The discrepancy between the satellite and ground-based measurements at 11 test sites did not exceed 2 m, which is mainly due to the difference in measurement techniques: height of individual trees by ground methods and continuous forest canopy height using radar interferometry.

The purpose of work was detection of regularities of bark formation on various parts of stems of Siberian larch Larix sibirica Ledeb. trees. In work, materials of ten trial areas established in larch stands of green moss group of forest types are used. 703 sample trees were cut down and measured. The trial areas were established at Priangarsky and Central Siberian subtaiga-forest-steppe forest vegetation regions. Sample trees were cut down into sections, equal to one tenth of the stem length. As a result of the carried-out works, the average sizes of double thickness of bark at stems of various diameter are established. The mathematical model, describing regularities of bark formation at various relative heights of stems of the Siberian larch trees with various diameters is constructed. This mathematical model is the basis for the auxiliary table containing data characterizing a bark share in diameter of a stem with bark. The relative sizes of bark on various sites of stems are established. For this purpose the double thickness of bark at height of the corresponding one-tenth height of a stem wood is taken for basic parameter. The bark sizes at other relative heights are expressed percentage of basic size. The relative sizes of bark changes from 206.8 % at the stem basis to 20.8 % for sections of the corresponding 0.9 shares of the stem height. The supplied generalizing information on the forest vegetation areas stated above is provided in work. The equation of pair dependence of relative double thickness of bark on the relative height of section of a stem is calculated. The obtained data might be used at creation of standards for valuation of the larch stands of the research area, such as volume, assortment and commodity tables.