A.V. Klimkin1, M.E. Levitskii1,2, M.V. Trigub1
a:2:{s:4:"TYPE";s:4:"HTML";s:4:"TEXT";s:200:"1V.E. Zuev Institute of Atmospheric Optics of Siberian Branch of the Russian Academy of Science, Tomsk, Russia 2Nauchno-vnedrencheskoe predpriyatie «Topaz», Tomsk, Russia";}
Keywords: International Conference, pulsed laser, laser application, laser physics, laser chemistry, laser material, laser source, excilamp
From September 12 to 17, 2021, the 15th International Conference on Pulsed Lasers and Laser Applications AMPL-2021 was held in Tomsk at the Institute of Atmospheric Optics, Siberian Branch, Russian Academy of Sciences . The topics traditionally reflected the results of research over the past few years: fundamental issues of laser physics, processes in laser active media, gaseous active media, new lasers and laser systems, laser applications, creation of devices based on laser sources, and new optical technologies.
Results of the study of features of the spectral, temporal, and spatial characteristics of the radiation from neutral neon atoms pumped by an inductive pulsed cylindrical discharge are presented. Lasing was obtained at wavelengths of 540.1 and 614.3 nm with optical pulse duration at levels of 13 ± 1 and 5 ± 1 ns (FWHM), respectively. The cross section of the laser radiation had the shape of a ring with a diameter of 33.1 ± 0.1 mm and a width of 5.6 ± 0.1 mm. The intensity distribution of the lasing ring was nonuniform and has a grain structure, typical of lasers operating in the amplified spontaneous emission mode. The grain region is inhomogeneous in form and size and shows a pronounced radial symmetry, which, according to our assumption, is due to the nature of the electric field in an inductive cylindrical discharge.
D.V. Shiyanov, V.A. Dimaki, M.V. Trigub, V.O. Troitskii, P.I. Gembukh
V.E. Zuev Institute of Atmospheric Optics of Siberian Branch of the Russian Academy of Science, Tomsk, Russia
Keywords: CuBr laser, energy input, cable pulse autotransformer, peaking capacitor, excitation pulse duration
A possibility of increasing the radiation power of a CuBr laser by increasing the pumping energy is studied. For this purpose, a three-cascade system of nanosecond oscillators is used, which excite the active medium of the laser when connected in series. Each source provides a pump power of up to 2 kW. A TGI1-1000/25 thyratron is used as a switch. The pump sources perform pulse charging of the working capacitance, which ensures stable operation of the system. The use of such a power source for excitation of a gas-discharge tube 5 cm diameter and 90 cm long provides for an output power of more than 40 W in a modified scheme with pulse cable autotransformer and peaking capacitor. Tests of the source confirm its effectiveness for pumping high power metal vapor lasers.
V.O. Troitskii
V.E. Zuev Institute of Atmospheric Optics of Siberian Branch of the Russian Academy of Science, Tomsk, Russia
Keywords: significantly nonlinear second harmonic generation mode, solution to a set of nonlinear equations, preset field approximation, optimization of focusing and wave detuning parameters
The process of second harmonic generation (SHG) of laser radiation in a BBO crystal is theoretically studied with the aim of determining optimal values of focusing and wave detuning parameters providing maximal SHG efficiency. This optimization problem is solved under an additional condition, that is, the maximal radiation power density should not exceed an a priori specified value. No restrictions are posed on the radiation power. The study consists of two parts. This is the second part of the work, where the influence of the additional condition on the process and results of solution of the optimization problem is studied using rigorous methods for solution of a system of nonlinear wave equations. The main results of the studies are the dependences of the maximum attainable SHG efficiency on the laser radiation power. It is shown that the optimal values of focusing and wave detuning parameters can be found with the use of the preset field approximation, which significantly reduces the amount of calculations, in many practical cases.
V.F. Tarasenko, E.Kh. Baksht, A.G. Burachenko, N.P. Vinogradov
High Current Electronics Institute of the Siberian Branch of the RAS, Tomsk, Russia
Keywords: mini jets, diffuse discharge, atmospheric discharges, red sprites, blue jets
The effect of the electrode material (aluminum and stainless steel) on the generation of mini-jets on the color of a pulse-periodic diffuse discharge in air, nitrogen, and argon is studied. A discharge was generated under generation of runaway electrons in an inhomogeneous electric field. It is found that the material of the electrodes significantly influences the color of the mini jets that originate when bright spots appear on the electrodes. It is confirmed that the use of aluminum electrodes colors the mini jets red, and of iron electrodes, blue. It is shown that the color of the discharge plasma in the mini jet region corresponds to the color of high-altitude atmospheric discharges (red sprites and blue jets) and differs from the color of diffuse discharges in air and nitrogen under the same pressure.
S.S. Anufrick1, A.P. Volodenkov1, K.F. Znosko1, V.F. Losev2 1Yanka Kupala State University of Grodno, Grodno, Belarus 2High Current Electronics Institute of the Siberian Branch of the RAS, Tomsk, Russia
Keywords: XeCl laser, LC circuit, lasing energy, basing parameters
The emission characteristics of a small-size XeCl laser (discharge plasma volume is ~ 10 cm3) are calculated based on a model taking into account specific features of operation of the excitation system, active medium, and cavity. Good agreement with experimental results is obtained.
S.S. Anufrick1, A.P. Volodenkov1, K.F. Znosko1, V.F. Losev2 1Yanka Kupala State University of Grodno, Grodno, Belarus 2High Current Electronics Institute of the Siberian Branch of the RAS, Tomsk, Russia
Keywords: XeCl mini laser, excimer laser, excimer molecule, pulsed discharge, discharge electrodes, peaking capacitance
An electric-discharge XeCl mini laser and the results of its experimental modeling are described. The laser uses a two-stage system of magnetic compression of current pulses, semiconductor high-voltage bipolar transistors as a switch, and preionization of the working medium by barrier discharge radiation from under the grid electrode. The dependence of the output parameters of the mini laser on the conditions of its excitation and the composition of the active medium is established. The maximal pulse energy of ~ 12 mJ was obtained for a mixture of the composition 1.5 torr HCl + 15 torr Xe + 4 atm Ne at a voltage across the peaking capacitor of 20 kV. The duration of the lasing pulses at half maximum was ~ 20 ns. The efficiency of the XeCl mini laser relative to the energy stored in the sharpening capacitor is ~ 4%.
S.V. Alekseev, V.F. Losev, A.G. Yastremskii
High Current Electronics Institute of the Siberian Branch of the RAS, Tomsk, Russia
Keywords: hybrid laser system, photodissociation XeF(C-A) amplifier, Ti:Sa start complex, chirped pulse, stretcher, compressor
The results of recent studies aimed at increasing the energy and peak power of THL-100 hybrid femtosecond laser system in visible range based on photodissociation XeF(C-A) amplifier and Ti:Sa femtosecond complex are presented. Two versions of the laser system operation based on the amplification of positively or negatively chirped pulses in the XeF(C-A) amplifier are analyzed. It is shown that when the positive-chirped pulse is amplified, the radiation energy maximum is achieved, and when the negative-chirped pulse is amplified, the power maximum is achieved.
D.V. Apeksimov, Yu.E. Geints, A.M. Kabanov, A.V. Petrov, E.E. Khoroshaeva
V.E. Zuev Institute of Atmospheric Optics of Siberian Branch of the Russian Academy of Science, Tomsk, Russia
Keywords: ultrashort laser radiation, structured light, Kerr effect, self-focusing, high-intensity light channels
Results of laboratory experiments on control of the filamentation domain of a focused femtosecond laser beam with a spatially structured (using a deformable mirror) wavefront are described. Aberration beams consisting of coherent interleaved ring subapertures obtained with a deformable mirror of specific form are studied. This allows producing inhomogeneities of the distribution of the optical field amplitude during laser beam propagation; these inhomogeneities can subsequently become seeds for light filaments. This approach to control high-power radiation filamentation does not require compensation for distortions of the initial beam profile; on the contrary, it is based on controllable introduction of pre-calculated wavefront aberrations.
L. Fiorani, F. Artuso, I. Giardina, M. Nuvoli, F. Pollastrone
ENEA Frascati Research Center, Frascati, Italy
Keywords: quantum cascade laser application, laser spectroscopy, photoacoustic technique, agrofood chain, rapid detection of food frauds, juice adulteration with added sugars
Economically motivated adulterations (EMAs) of food and juice are a serious threat to our health. Although several accurate analytical methods are available to detect fraudulent ingredients in the supply chain, fast and user-friendly techniques are still missing, especially if reliable deployment in industrial settings is needed. After many years of application of laser photoacoustic spectroscopy (LPAS) to food fraud detection with CO2 lasers, the Diagnostic and Metrology Laboratory of ENEA developed a portable and robust prototype based on a quantum cascade laser (QCL) to rapidly and easily identify EMAs in real scenarios. Fruit juice was used as a case study to evaluate its performance. Two EMAs were sensed in a few minutes and chemometrics tools allowed their quantification
A.A. Zhiltsova1, O.A. Filippova1, E.D. Krasnova1, D.A. Voronov2, S.V. Patsaeva1 1Lomonosov Moscow State University, Moscow, Russia 2Institute for Information Transmission Problems of the Russian Academy of Sciences (Kharkevich Institute), Moscow, Russia
Keywords: bacteriochlorophyll, fluorescence, absorption spectrum, anoxygenic phototrophic bacteria, green sulfur, stratified reservoirs, the White Sea
An important characteristic of a natural reservoir is the distribution of the pigment composition of various groups of photosynthetic organisms over depth and its changes in different seasons. Optical methods are widely used to monitor the concentration of chlorophylls of algae or cyanobacteria in aquatic ecosystems, but they are very limited used to monitor the bacteriochlorophyll (BChl) concentration of phototrophic bacteria. The paper describes in detail three methods of quantitative analysis of the photosynthetic pigment of BChl d of green sulfur bacteria using spectral measurements both in initial samples of natural water (optical density spectra) and in pigment extracts in organic solvents (absorption and fluorescence spectra). A comparative analysis of the results of different methods is carried out on the example of natural water from the chemocline region of the lake Trekhtzvetnoe, one of the meromictic reservoirs of the Kandalaksha Bay of the White Sea (water from different depths was selected in March 2021). The conclusions about the conditions of applicability of different methods, their advantages and limitations were made. All three methods for estimating the BChl concentration have proved their applicability on the samples of natural water with BChl concentrations differing by orders of magnitude, from 5 to 5000 mg/m3.
G.P. Kokhanenko, Yu.S. Balin, A.G. Borovoi, M.M. Novoselov
V.E. Zuev Institute of Atmospheric Optics of Siberian Branch of the Russian Academy of Science, Tomsk, Russia
Keywords: crystal clouds, polarization lidar, depolarization, particle orientation
Results of studies of the horizontal orientation of crystalline particles carried out using a scanning polarization lidar LOSA-M3 are presented During 2018-2021, several series of measurements of the structure of high-level crystalline clouds were carried out in the zenith scanning mode. In contrast to sounding only in the vertical direction, observations of the dependence of the lidar signal characteristics (intensity and depolarization ratio) on the angle of lidar axis inclination make it possible to identify the phase composition of clouds (water or crystalline) and measure the distribution of particle deviation relative to the horizontal plane (flutter). In layers with a pronounced specular reflection, the relationship between the signal intensity and the slope of the sounding path at small angles (up to 5°) is well described by an exponential dependence. The results of sounding when scanning up to angles of 45-50° showed a high probability of the existence of a corner reflection in ice clouds.
S.N. Andreev1, V.P. Tarakanov2 1Moscow Polytechnic University, Moscow, Russia 2Joint Institute for High Temperatures of Russian Academy of Sciences, Moscow, Russia
Keywords: proton beam, super-intense laser pulse, PIC simulation, quasi-neutrality
Generation of a quasi-neutral beam of protons and electrons during the interaction of an ultra-high intensity laser pulse with an aluminum target with a layer of protons on the rear surface is studied. It is shown that the time of setting the quasi-neutrality of the proton beam is more than five time longer than the laser pulse duration.
L. Hongda1, M.V. Andreev2, Yu.N. Panchenko2, A.V. Puchikin2 1Shenyang Ligong University, Liaoning, No.6, Shenyang, China 2High Current Electronics Institute of the Siberian Branch of the RAS, Tomsk, Russia
Keywords: KrF-laser, alignment automation, optical system, filtration methods
The results of numerical and experimental studies on the control and management of optical elements of an electric-discharge KrF laser using the developed method based on DBSCAN are presented. Various methods for processing the data obtained from the position-sensitive detectors and a possibility of using the DBSCAN algorithm to increase the speed of the optical system alignment automation device are considered. The conditions for correcting controlled mirrors with an accuracy of their return of 60 ± 10 mrad are determined. The adjustment time does not exceed 5 min.
Ecologically correct forest management in city forests is impossible without full inventarisation of their biodiversity. Vegetation classification by the Braun-Blanquet method could be important step in the direction of the complex data base creation about city forests biodiversity as an essential part of ecological monitoring and planning of the forest management. The main aim of this research was comparative study of two forest areas with different level of disturbances in Novosibirsk city and their classification by the Braun-Blanquet method. In course of the detailed description 42 full geobotanical relèves were made as a basis for the classification. Depending on the level of the anthropogenic disturbances six syntaxa of the association and subassociation rank were described in city forests. Four of them were described first time. Natural forest vegetation of the area is presented by the two associations from Brachypodio pinnati-Betuletea pendulae class - Calamagrostio arundinaceae-Betuletum pendulae in mesic habitats and Trollio asiaticae-Populetum tremulae in moist habitats. Growing anthropogenic pressure in the modern megapolis leads to deep changes in the forest community structure and composition. Syntaxonomically this transformation could be described in two new subassociations Calamagrostio arundinaceae-Betuletum pendulae aceretosum negundi and Trollio asiaticae-Populetum tremulae aceretosum negundi respectively. They differ by the poor combination of the class diagnostic species and the presence of ruderal and meadow species including aggressive alien species. In case of the excessive anthropogenic pressure and soil eutrophication ruderal, nitrophylous and alien species start to dominate in community composition, especially in shrub layer. Such forests were described in frame of the new association Pino-Aceretum negundi with two subassociations typicum and impatientosum parviflorae, belonging to Robinietea class - spontaneous forests vegetation in city parks. Forests of this class are described in Siberia for the first time. So, vegetation classification of city forests by the Braun-Blanquet method gives possibilities to distinguish different stages of the anthropogenic transformation and to estimate recent forest conditions and their potential of recovering.
T.A. Sokolova
Southern Scientific Center RAS, Rostov-on-Don, Russia
Keywords: oak forests of the steppe basin of the Don River, syntaxonomy, union Aceri campestris-Quercion roboris
The paper presents the results of long-term studies of the vegetation of bayrachny oak forests in the south of the European part of Russia (Volgograd, Voronezh, Rostov regions). Based on a large amount of factual material (more than 1150 geobotanical descriptions, including 777 descriptions by G.M. Zozulin), a floristic classification of mesophytic oak forest communities in the region, which are attributed to the alliance Aceri campestris-Quercion roboris Bulokhov et Solomeshch in Bulokhov et Semenishchenkov 2015, was carried out using the Braun-Blanquet method (1964). For a long time, the forests of the south of the European part of the country, due to little study, belonged to the alliance Aceri tatarici-Quercion Zólyomy 1957. New data (Goncharenko et al., 2020; Sokolova, Ermolaeva, 2021) made it possible to clarify their position in the classification system of forest vegetation in Russia. A new association was installed Ulmo minoris-Fraxinetum excelsioris ass. nov. hoc loco and the new suballiance Ulmo minoris-Fraxinenion excelsioris suball. nov. hoc loco in the alliance Aceri campestris-Quercion roboris. The new syntaxons are transitional forest communities with features of the Carpino-Fagetea Jakucs ex Passarge 1968 and Quercetea pubescentis Doing-Kraft ex Scamoni et Passarge 1959 classes. Their distinctive feature is the presence of both non-moral phagetals: Adoxa moschatellina, Aegopodium podagraria, Asarum europaeum, Campanula trachelium, Corylus avellana, Lathyrus vernus, Milium effusum, Pulmonaria obscura, Viola mirabilis, etc., and species with circumpontic distribution: Arum elongatum, Dentaria quinquefolia, Laser trilobum, Lysimachia verticillaris, Physospermum cornubiense, Scilla sibirica, Symphytum tauricum, Veronica umbrosa, Vincetoxicum scandens, which are characteristic of the recently isolated alliance Scutellario altissimae-Quercion roboris Goncharenko et al. 2020, which unites the subxerophilic oak forests of Ukraine and southern Russia, found in the steppe zone and the southern part of the forest-steppe zone. The ideas about the area of the alliance Aceri campestris-Quercion roboris, which has expanded beyond the forest-steppe zone to the central regions of the Rostov region, have been expanded.
I.B. Kucherov1, L.A. Novikova2, S.A. Senator3 1V.L. Komarov Botanical Institute RAS, St. Petersburg, Russia 2Penza State University, Penza, Russia 3N.V. Tsitsin Central Botanical Garden RAS, Moscow, Russia
Keywords: multizonal species, meadows, dry grasslands, meadow steppes, latitudinal zonation, European Russia
As follows from the analysis of relevés collected in the 13 key areas in European Russia (see Table 1, Fig. 1), phytocoenotic behavior of many multizonal meadow species of vascular plants changes notably when passing from the boreal- and then the nemoral-forest zones to the subzone of meadow steppes. The constancy and cover of the 17 model species, distributed along the latitudinal zones and subzones and then the dry grassland, meadow, and steppe vegetation types (see Table 2), is influenced by warmth supply and climate continentality factors together with those of location within a particular river basin and regional specifics of the Quaternary history. Zonal trends of cover changes for Stellaria graminea and Bromopsis inermis in the series from dry boreal grasslands to steppes or from northern to southern Calamagrostis epigeios-dominated meadows, respectively, are proved by the Spearman rank correlations between the mean cover and the growing degree-days above 10 C or the Konrad continentality index (see Table 3). Xerophytization of many species, mesic in the boreal-forest zone, is observed under the steppe conditions, the process which often results in the separation of new micro-species. The anemochorous meadow plants were subject to dispersal mainly along the watersheds but the barochors were dispersed mainly by water flow or in both ways in the course of the formation of meadow-steppe coenofloras in the Late Pleistocene and the Holocene. Both redwood-dry-grassland and floodplain-meadow coenofloras influence the steppe set of meadow species, and the latter can be grouped into the three ecological-historical “corteges” of vegetation, namely the watershed, the floodplain, and the combined ones.
We studied the seed set of the andromonoecious Chaerophyllum aromaticum (Broadleaf chervil), a perennial or biennial polycarpic herbaceous plant. Our survey was carried out in natural conditions of the Moscow region from 2018 to 2021 according to generally accepted methods of studying plant seed sets. We showed that the seed set of individuals depends on the degree of synflorescences branching. Broadleaf chervil has three types of individuals with double umbels on shoots of I-II, I-III, and I-IV orders. C. aromaticum has a high potential (number of ovules per individuals) and real (number of seeds per individuals) seed set (up to 3500 seeds per individual) and the proportion of perfect flowers forming full seeds (92-93 % per individual). The potential and real seed set of terminal double umbels is higher than that of individual double umbels on shoots of the following orders in individuals with the least and most branched synflorescences. In individuals with double umbels on shoots of I-III orders, the number of ovules and seeds in double umbels on shoots of II order is higher than in terminal double umbels. In Broadleaf chervil, the seed set of double umbels on shoots of the same branching order naturally increases with an increase in the branching of the shoot system. The contribution of the seed set of double umbels to the total seed set of C. aromaticum individuals also depends on the degree of synflorescences branching. With an increase in the branching of the shoot system, the share of seed set of terminal double umbels and double umbels on second-order shoots gradually decreases. These characteristics of double umbels on third-order shoots naturally increase due to both their numerical predominance and, in some cases, a greater number of ovules and seeds formed by them. A high seed set ensures successful seed reproduction of Broadleaf chervil in natural conditions.
Y. V. Naumenko1, Ch.D. Nazyn2 1Central Siberian Botanical Garden of the Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia 2Tuvan State University, Kyzyl, Russia
Keywords: Algae, taxonomic composition, Cyanoprokaryota, Bacillariophyta, Republic of Tyva
For the first time, information is provided about the Ceiba River and its tributary Khon, which carry their waters in the state nature reserve of republican significance “Khutinsky”, located in the spurs of the southern macro slope of the Western Sayan. A list of algae is given, including 89 species and intraspecific taxa, which belong to 51 genera, 28 families, 8 classes and 4 divisions. It has been established that the basis of algoflora consists of diatoms and blue-green algae. Common dominants have been identified for two rivers: Meridion circulare and Diatoma mesodon, D. hiemale and Didymosphenia geminata. An ecological and geographical analysis was carried out, according to which algoflora is represented by benthic species, with a predominance of indifferent forms in relation to halobicity and active reaction of the environment. 72 types of water saprobity indicators were identified in the studied watercourses. The predominance of betamesosaprobionts and oligosaprobionts was noted. Cosmopolitans and Boreal species dominated geographically.
Flora of halophytic vegetation within Western Zabaikaliye is overviewed. Three hundred thirty six species and
subspecies of vascular plants from 163 genera and 52 families have been registered. The distinct specificity of
flora is a high rank of Chenopod family in the families’ spectra, and Chenopodium, Suaeda, as well as Plantago,
Puccinellia — in the genera’ spectra. Enrichment of the saline habitat flora is achieved mostly due to numerous
glycophytes tolerant to substrate salinity. Despite it, plant communities in saline habitats are always predominating
by halophytes. The preliminary classification of halophytic plant communities in accordance with Braun-Blanquet approach is
proposed. As a result 3 orders, 4 alliances, 14 associations, 4 subassociations, and 11 variants, belonging to the
classes Scorzonero-Juncetea gerardii and Thero-Salicornietea, are distinguished. The first class contains the majority
of recognized syntaxa. Such features as great variability of synmorphology, widely fluctuating physiognomic
aspects, and mostly low species richness have been noted as typical of halophytic plant communities.
E.Z. BAISHEVA
Institute of Biology, Ufa Scientific Center of RAS, 450054 Ufa, October av., 69 elvbai@anrb.ru
Keywords: bryophytes, forest-steppe, oak-woods, pine-woods
The results of study of bryophytes in the moderately dry oak-woods (all. Lathyro-Quercion roboris), pine forests
(all. Caragano fruticis-Pinion sylvestris) and larch-birch forests (all. Veronico teucrii-Pinion sylvestris) of the South
Urals are discussed. Eighty moss species and 8 liverworts have been revealed. Forty nine percent of bryophyte
species have low constancy. The lowest diversity of bryophytes is characteristic of larch-birch forests (23 species)
and oak-woods (32 species), the highest — of pine forests (83 species). Species that grow on the bases of
tree trunks and on the rotten wood (Pylaisia polyantha, Pseudoleskeella nervosa, Stereodon pallescens, Sciuro-hypnum
reflexum, Brachytheciastrum velutinum, Plagiomnium cuspidatum, Platygyrium repens) have high constancy. In the
forest communities which are developed on the slopes, epilythic bryophytes of carbonate rocks (Tortella tortuosa,
Schistidium apocarpum s.l., Pseudoleskeella tectorum) and ground light-loving species (Abietinella abietina,
Ceratodon purpureus, Rhytidium rugosum, Syntrichia ruralis) are abundant. In comparison with moderately dry
forests of the Russian Plain, communities from the South Urals are distinguished by almost complete absence
of ruderal moss species. This indicates low disturbance and natural character of the Urals communities and
emphasizes their high conservation value.
D.V. SANDANOV
Institute of General and Experimental Biology, SB RAS, 670047 Ulan-Ude, Sakhyanovoi str., 6 denis.sandanov@gmail.com
Keywords: Scutellaria, Sophora, Astragalus, distribution of plants, ecological gradients, ecological scales, population optimum, Zabaikaliye, Inner Mongolia
Populations of East-Asian species (Sсutellaria baicalensis, Sophora flavescens, and Astragalus membranaceus) in the
territory of Zabaikaliye, the Russian Far-East and Inner Mongolia were studied. A total of 363 relevees were
processed using the ecological scales, and ranges of environmental conditions were evaluated. To assess population
optimum, the individual and cenopopulation features were taken into account. As the most appropriate,
the ecological scales method proposed by I.A. Tsatsenkin et al. (1978) for analyzing forest-steppe communities
was used. By integrating data on plant communities and populations the optimal conditions for each species
were revealed. Generally, habitats of South and South-Eastern part of Zabaikaliye and the Russian Far-East are
the most favorable for the species under study. We conclude that moisture might be the key factor for functioning
of populations of East-Asian species.
J.H. DAI, M.M. WANG, H.J. WANG
Institute of Geographic Sciences and Natural Resources Research, CAS, 11A Datun Road, Beijing, 100101, China daijh@igsnrr.ac.cn
Keywords: borderland between Shaanxi-Gansu-Ningxia, climate change, relationship between climate and vegetation
Indices of temperature, precipitation and relative evapotranspiration (RET) for the last 51 years in the borderland
between Shaanxi and Gansu Provinces, and Ningxia Hui Autonomous Region (BSGNAR) were calculated
to analyze the climate change in this area. During the past 50 years, the average temperature increased
significantly, while precipitation decreased slightly with regional differences. RET change was not so distinct
in general, but had a minor increase at the late stage of the study period. Under such circumstances, climate
change had clear effects on distribution of potential vegetation in the area, with a tendency to transit to warming
and drying vegetation types.
A comprehensive study of the critical taxon Leymus buriaticus Peschkova was carried out in comparison with
natural and cultivated populations of L. littoralis and L. chinensis from various localities in Buryatia. The factorial
analysis performed by 15 morphological characters showed that L. buriaticus occupied an intermediate position
between L. chinensis and L. littoralis. SDS-electrophoresis of individual seeds showed presence of similarity
of relations between samples identified as L. buriaticus and selected samples of L. littoralis and L. chinensis in
mixed population from a classical locality. The analysis of subfractional composition of histon Н1 also revealed
presence of common subfractions of L. littoralis, L. chinensis and L. buriaticus. It was concluded that the endemic
L. buriaticus was of a hybrid origin.
Typification of 20 Primula L. (Primulaceae) taxa from Siberia and the Russian Far East kept in the Herbarium of V. L. Komarov Institute of Botany was carried out. The citation of the place of valid publication, categories of type specimens, label, protologue, currently accepted name or synonym, and locality are presented for the taxa. Holotypes for 5 taxa, lectotypes for 15 taxa, 28 syntypes and 1 paratype are given. A photography of the lectotype is published for P. patens.
Data on distribution of anthropophilous species of the genus Calystegia in Siberia were summarized. Their
status in region flora was considered and maps of areas of these species were made for the first time.
Polyporus choseniae (Vassilkov) Parmasto and P. pseudobetulinus (Murashk. ex Pilat) Thorn, Kotir. et Niemela were found in the mountain riverside woods of the Altai Krai and the Altai Republic for the first time. New
localities were indicated for 8 Polyporus species known earlier.
The class Loiseleurio-Vaccinietea in the territory under study is represented by 4 associations and 2 subassociations.
The associations and subassociations have been described for the first time. Three associations: Dryado
octopetalae-Eriophoretum vaginati, Ptilidio ciliares-Alnetum fruticosae and Cetrario laevigatae-Racomitrietum
lanuginosi occupy the largest areas. They thrive in upper flat and prominent parts of watersheds.
Mire areas with unusual structure were found and studied in the south-east of West Siberia. They are
represented by a series of parallel ribbons in river valleys; the central parts of the mires are formed by complexes
of mesotrophic pools with Carex species and forested peat beds. The mire areas are characterized by higher
species diversity and by presence of rare and endangered species. Description is given.
The steppe belt of Tannu-Ola southern macroslope contains two subbelts. The main communities of the subbelt
of desert steppes (1000–1300 m) are represented by desert steppes (Nanophyto grubovii-Stipetum krylovii, Lagochilo ilicifolii-Stipetum glareosae)
and communities where Stipa orientalis predominates (Elytrigio geniculatae-Stipetum orientalis). The main communities of the subbelt of true steppes (1300–1600 m) are represented by bunchgrass
steppes (Artemisio frigidae-Stipetum krylovii) and steppes of ass. Carici pediformis-Caraganetum bungei.
Ecological-phytocoenotic position of annual halophytic Suaeda in the south-east of the West Siberian Plain was analyzed. The place of plant communities dominant by Suaeda species in Braun-Blanquet classification was
determined. Five associations and two communities were characterized. New association Suaedetum kulundensis and community of Suaeda tuvinica were described.
Individual morphogenesis and ontogenetc structure of coenopopulations were studied; current status of Bupleurum scorzonerifolium coenopopulations in Buryatia was assessed by a complex of characters.
Biomorphological structure of Baikalo-Lensky State Nature Reserve flora and its separate floristic complexes was analyzed by means of K. Raunkier’s and I.G. Serebryakov’s approaches. Some biomorphs reflecting
extreme climatic conditions, as well as some ecobiomorphs reflecting edaphotopic conditions of the leading floristic complexes were considered.
Cell structure of the leaf blade mesophyll was studied in 4 species of grasses of the genus Festuca (F. gigantea, F. pratensis, F. pseudovina and F. valesiaca) distributed in different natural and climatic conditions of Siberia. The
main shapes of cell chlorenchyma were identified. General and distinguishing features of spatial organization of assimilatory tissue of the leaves were revealed and characterized in Festuca species under study.
The results of study of flavonoid content and composition of Bistorta officinalis Delabre from natural habitats in Siberia are given. Plants growing in the conditions of increased insolation at a height of 1500–2000 m and
higher contain more flavonoids than plants of meadow communities in the plain, which indirectly confirms their protective function. A range of variations of the flavonoid content in mass flowering period amounts to 1.13–5.61 % (in flowers) and 0.69–5.10 % (in leaves). Flavonol aglycons were studied by HPLC methods in the plants collected in the Altai.
Algae were studied in the eutrophic peat bog (Plesetsk Region, Arkhangelsk Oblast). One hundred sixteen
species represented by 120 specific and intraspecific algal taxa were identified. The division Chlorophyta
prevailed. Spectra of life forms, ecological groups and morphotypes of algae were determined. Both typically
edaphophilous and hydrophilous species (history of the biotope) take part in formation of soil flora of the bog.
Sixteen species of maple are promising for introduction in Siberia. The diversity of forms was studied.
Literature and Russian and foreign web-based information on woody plants were analyzed. Four hundred and fifty four subspecies,
variants and forms of interest as ornamentals were identified for 12 species. Biological, ornamental and ecological characteristics of them and figures are given.
