Steppe Flora Research Articles

Vascular plants of old cemeteries in the Lower Dnipro region (Southern Ukraine).

The dataset contains the records of vascular plant species occurrences and distribution in old cemeteries (OC) of the Lower Dnipro region (Southern Ukraine). The analysed cemeteries were located in different types of landscapes (agricultural, rural and urban) and represent various ways of using their area (currently used, closed, abandoned). The floristic list includes 440 species of vascular plants (437 in situ, 3 ex situ). The dataset demonstrates a sozological (Red-lists species) value of old cemeteries in Southern Ukraine. The cemeteries constitute refuges of native, rare and steppe flora and play a role of steppe habitat islands in a landscape almost completely transformed to arable land or urbanised. This is the first dataset which contains information about flora of old cemeteries in Lower Dnipro region (Southern Ukraine). The dataset comprises 2118 occurrences of vascular plants (440 species) recorded in the years 2008-2021 in 13 old cemeteries of the Lower Dnipro region. The dataset includes information about 85 occurrences of rare species (23 species in situ, 3 ex situ) and 652 occurrences of 117 steppe species.

Genotyping-by-sequencing reveals range expansion of Adonis vernalis (Ranunculaceae) from Southeastern Europe into the zonal Euro-Siberian steppe

The Euro-Siberian steppe flora consists of warm- and cold-adapted species, which may have responded differently to Pleistocene glacials and interglacials. Genotyping-by-sequencing individuals from across the distribution range of the pheasant’s eye (Adonis vernalis), we aimed to gain insight into steppe florogenesis based on the species’ evolutionary history. Although the primary area of origin of the species group comprising A. vernalis, A. villosa and A. volgensis is in Asia, our results indicate that recent populations of A. vernalis are not of Asian origin but evolved in the southern part of Europe during the Pleistocene, with Spanish populations clearly genetically distinct from the Southeastern European populations. We inferred that A. vernalis migrated eastwards from the sub-Mediterranean forest-steppes of Southeastern Europe into the continental forest-steppe zone. Eastern European populations had the highest private allelic richness, indicating long-term large population sizes in this region. As a thermophilic species, A. vernalis seems unlikely to have survived in the cold deserts of the Last Glacial Maximum in Western Siberia, so this region was likely (re)colonized postglacially. Overall, our results reinforce the importance of identifying the area of origin and the corresponding ecological requirements of steppe plants in order to understand the composition of today’s steppe flora.

Origin of the central European steppe flora: insights from palaeodistribution modelling and migration simulations

The biogeographic origin of the species‐rich steppe grasslands in central Europe has long been debated. The alternative hypotheses are long‐term species persistence in situ versus immigration from the south‐east, either after the last glacial maximum (LGM) or after the Neolithic landscape deforestation. We ask whether macroclimate‐based models of habitat suitability support either of these hypotheses and search for macroclimatically suitable ‘source areas' from which species could colonise the areas occupied in Europe today. We modelled habitat suitability for 104 species of the central European steppes and projected these models to 10 periods between the LGM and the present using downscaled CCSM3 simulations. By simulating postglacial migration, we identified potential source areas for each species in the LGM and mid‐Holocene and examined whether their location differed among three ecological and five chorological species groups.The central European macroclimate during the cold phases of the Late Pleistocene was suitable for species now typical of Asian desert steppes, whereas the warmer Bølling–Allerød and Holocene macroclimates supported the occurrence of present‐day central European steppe flora. The models suggest that the LGM source areas of these species ranged from south‐eastern France through the Adriatic region and the Balkan Peninsula to the Black‐Sea region but extended to central Europe in the mid‐Holocene. Their locations differed considerably among ecological and chorological groups in both periods. Therefore, our models support the hypothesis that during the Pleistocene cold periods, the largest populations of these species occurred in southern and south‐eastern Europe and some of them may have later colonised central Europe. If some populations occurred in central Europe during the LGM, as suggested by recent genetic analyses, they were likely restricted to microrefugia embedded in the landscape matrix of species‐poor cold steppe. The precipitation‐rich mid‐Holocene climate had no direct negative impact on the central European steppe flora.

N-Alkanes and their carbon isotopes (δ13C) reveal seasonal foddering and long-term corralling of pastoralist livestock in eastern Mongolia

The compound-specific δ13C values of n-alkanes from pastoralist winter campsites in Mongolia have great potential to reconstruct dietary seasonality of livestock and local vegetation. We analysed leaf wax n-alkanes and their carbon isotope ratios in common fodder plants (Artemisia mongolica, Chenopodium album, Elymus dahuricus, Elymus sibiricus and Stipa sibirica) fed to domesticates during the winter months, and also in topsoils (0–8 cm) from four livestock corrals in northern and southern Mongolia. n-Alkanes identified in fresh plant parts reflect signatures with mean δ13C stable isotope values of individual n-alkanes typical for C3 plants (−34.1‰). Plants from forest- and desert-steppe exhibit similar mean n-alkane δ13C values but significantly wider isotopic variation in the desert steppe flora. The non-anthropogenic control samples exhibit δ13C mean values significantly higher from that of dung deposits and fresh plants for the same regions. Our data support previous research that n-alkanes profiles and their carbon isotopic values vary depending on the local vegetation and environment, while simultaneously demonstrating how anthropogenic activity, such as corralling of livestock, is recorded in the n-alkane of domesticates dung validating the use of biomarker studies in pastoralist archaeological contexts for distinguishing seasonal foddering, local environmental data and to an extent grazing habitats.

On the structure of populations of rare steppe plant species under anthropogenic pressure (Middle and Lower Volga region)

In the article the population structure of 20 rare representatives of flora of the Middle and Lower Volga region (European part of Russia) is considered. Methods of population-ontogenetic direction were used during the work. Data on cenopopulations were obtained by medium- and long-term monitoring. The structure of cenopopulations of 20 species was studied: Ajuga chia Schreb., Artemisia salsoloides Willd., Artemisia santonica L., Artemisia taurica Willd., Astragalus cornutus Pall., Astragalus temirensis M. Pop., Astragalus zingeri Korsh., Atraphaxis frutescens (L.) C. Koch., Cephalaria uralensis (Murr.) Schrad. ex Roem. et Schult., Clausia aprica (Steph.) Korn.-Tr., Halocnemum strobilaceum (Pall.) M. Bieb., Hedysarum gmelinii Ledeb., Hedysarum grandiflorum Pall., Hedysarum razoumovianum Fisch. et Helm, Medicago cancellata Bieb., Oxytropis floribunda (Pall.) DC., Oxytropis hippolyti Boriss., Polygala sibirica L., Silene cretacea Fisch. ex Spring., Rindera tetraspis Pall. It was established that population characteristics of many rare representatives of the steppe flora of the Volga region are similar and depend on the type and duration of ontogenesis, life strategy and intensity of anthropogenic pressure on the places of growth.

Old cemeteries as refuge of the steppe flora in Southern Ukraine

Changes in natural landscapes and economic activities lead to the loss of a large proportion of the steppes. Recent studies (2008–2017) have demonstrated the high importance of old cemeteries, that contribute to the preservation of steppe red-listed steppe species. The area of the old cemeteries of the Lower Dnieper varies from 0.43 ha to 6.79 ha. The list of vascular plants from 10 cemeteries of the Lower Dnieper region includes 388 species belonging to 226 genera, 62 families, 3 classes and 2 divisions. The total number of species within cemetery varied from 104 to 217 (on average 153 species). In old cemeteries of the studied region, rare steppe species have survived, although steppe vegetation is preserved where there are fragments of virgin and unploughed steppes around the cemeteries, near old villages or cities. 22 protected vascular plant species were found in the studied old cemeteries (5.65 % of the total species pool). Five of these are included in the Red Data Book of Ukraine: Astragalus henningii, Stipa capillata, Stipa lessingiana, Stipa ucrainica, Tulipa biebersteiniana. 17 species of vascular plants are included in the Red List of the Kherson region: Amygdalus nana, Bellevalia sarmatica, Centaurea trichocephalla, Convallaria majalis, Dianthus andrzejowskianus, Elytrigia pseudocaesia, Ephedra distachya, Fraxinus excelsior, Iris halophila, Limonium platyphyllum, Linaria macroura, Muscari neglectum, Peucedanum ruthenicum, Prangos odontalgica, Quercus robur, Veronica capsellicarpa, Vinca herbacea.

Bioenvironmental characteristics of Robinia pseudoacacia steppe plantations in dependence to changes in some climatic factors

Сlimatic factors play the most important role in the plant associations formation. Sunlight is one of the leading factors that determine the appearance of a particular community and very often plays the limiting factor role. In the conditions of the Steppe Dnipro Region, its limiting role can be expressed only in its excess. The great majority of autochthonous steppe flora plant species has strongly pronounced adaptations to excessive solar insolation. With the development of forest biogeocenology and steppe forestry, more and more attention is paid to the issues of forest climatology. It is shown that climatic factors have an imperative effect on the formation of soils, plant associations, fauna and ecosystems in general. Artificial plantations consisting of fast-growing hardwoods, such as Robinia pseudoacacia, have been studied. The complex of abiotic factors in robinia plantations and in open areas has its own characteristics. The processes of reflection, transformation and accumulation of solar energy in tree plantations have a slightly different character than in forest-free areas. In the Dnipropetrovsk region, the populations of Robinia pseudoacacia are represented mainly by young plants that have already entered the phase of active fruiting. No plants older than 100 years were found in the populations. Thus, the price spectrum of the age composition of the population of Robinia pseudoacacia in the Dnipropetrovsk region has a pronounced left-sided character, ie shifted towards young individuals that are actively fruiting. This indicates that the processes of expansion of Robinia pseudoacacia to natural biogeocenoses will be actively continued. Despite the fact that this breed has a number of positive qualities (excellent medonis, root mycorrhiza with azotobacter, high gas resistance, etc.), the processes of uncontrolled active settlement of this species is a matter of serious concern. This breed is capable of rapid spread and disruption of successional processes occurring in the area. In the conditions of the forecasted climate changes towards temperature increase and precipitation decrease this breed receives more and more advantages.

Floristic transformation of the steppe area in the lower reaches of the Osyotr River due to anthropogenic impact

The purpose of this study was to survey the steppe site located on the right bank of the Osyotr River, near the village of Argunovo, in the urban district of Zaraysk, Moscow Region. It was required to analyze the key floristic changes that have occurred in its composition to date. For comparison, the floristic description of this site, detailed by R.I. Dyakova in the 1950s. The work takes into account the fact of man-made interference in the 1960s, as a result of limestone mining there in violation of the vegetation cover. In the autumn, 2020 the authors of this article studied a steppe site in the neighborhoods of the village of Argunovo in Zaraisk urban district of Moscow region and collected a herbarium donated to funds [MHA]. This steppe community was first discovered and described in detail by R.I. Dyakova in the 1950s. In the 20th century, due to the extraction of limestone in the lower reaches of the Osyotr River, this biotope was disturbed. It was established that over the past 70 years, the area occupied by the association with Stipa pennata L. and Geranium sanguineum L. significantly decreased and some steppe species disappeared. A factor in the transformation of the steppe cenosis was also cessation of grazing, which led to the appearance of a number of meadow-steppe species. The studied area near the village of Argunovo can be considered as a unique meadow-steppe reserve. It is located at the northern border of the forest-steppe zone and includes the elements of the Oka steppe flora that has preserved to this day. The populations of rare and protected species have been preserved: Stipa pennata, Aster amellus L., Campanula bononiensis L., Gentiana cruciata L., Rosa villosa L. and Pyrus communis L., included in the Red Data Book of Moscow Region. The studied area is potentially susceptible to the invasion of alien species (Heracleum sosnowskyi Manden, Acer negundo L.) and needs monitoring and protection at the level of the community, population and each species.

Rare species of natural steppe flora – on prospects for their conservation in Samara region in situ and ex situ

The virgin steppes survived only in inappropriate for plowing places or in natural reserves are valuable natural heritage due to significant number of world’s flora protected species. This article is devoted to comparison of passive and active measures of biological diversity preservation for regional flora rarities. A spatial analysis in the Arc View GIS3.2 system was used for distribution study of protected areas and rare plant species according to the municipal districts of Samara region. The results of the Botanical Garden activities native flora preservation are given using data of its flora department and 2011-2020 delectuses. The number of higher plants species included in regional Red Data Book found in municipal districts varies from 23 to 115, whereas protected areas percentage there does not reach 5%, only in two slightly exceeds it. The natural monuments have low efficiency as natural reserves for highly fragmented steppe ecosystems. The passive measures for the biodiversity conservation need to be supplemented by active ones. Over 10 years, the Botanical Garden of Samara University provides ex situ conservation for 39 flowering plants species included in regional Red Book as permanent populations. The fund of ex situ plants is successfully used for reintroduction.

Новинка для флоры Китая: сибирский «эндемик» Euphorbia karoi (Euphorbiaceae) встречается в южной части Внутренней Монголии

Euphorbia karoi, a species described from South Siberia (the vicinity of Nerchinsk) and known from only a few gatherings, is reported from China, the southern part of the Inner Mongolia Autonomous Region. This species was collected by the Russian expedition led by P. K. Kozlov (1908) in the Helan (Alashan) Mountains and also in the Jiufeng Mountains (according to the specimen image from PE Herbarium). E. karoi is accepted here in the strict sense; its taxonomic status and characters are discussed. The current disjunction in its distribution may be explained by the expansions of the steppe and desert flora into Siberia from Central Asia during the Cenozoic.

The current state and biodiversity of steppe phytocenoses in the territory of the Kabardino-Balkarian Republic

In connection with the importance of preserving and restoring steppe landscapes, the purpose of the study was to monitor the state and biodiversity of steppe phytocenoses in the territory of the Kabardino-Balkarian Republic. Geobotanical survey was carried out in the steppe and foothill zones of the republic in 2018-2020. According to the monitoring results, it was found that an increase in pasture digression correlates with a depletion of the floristic composition, a decrease in the projective cover, the height of the herbage and the productivity of aboveground phytomass, an increase in the level of synanthropization and a simplification of the vertical structure. With an increase in anthropogenic influence in plant communities, the level of synanthropization increases to 78.6%. The decrease in the projective cover in 1.5-3.3 is a consequence of the long and irrational use of pastures. As a result of intensive grazing, the productivity of the aboveground phytomass decreases by 9-12 times, and the height of the grass stand - by 2.5-5.0 times compared to the reference steppe phytocenoses. To preserve steppe phytocenoses, a set of measures is needed, including the ecologization of agriculture, the development of measures for the ecological restoration of disturbed steppe ecotopes, the prevention of negative phenomena of invasion, the creation of nurseries of steppe flora and steppe reserves, the inclusion of species that are in danger of complete extinction in the Red Book of the flora of Kabardino-Balkaria.

Steppe flora in Serbia – distribution, ecology, centres of diversity and conservation status

The steppe flora and vegetation represents a significant part of the Eurasian temperate grassland biome. In Serbia, this flora is a part of the biome’s western border zone and its characteristics therefore may be modified. The aim of this study was to determine the number of steppe taxa in Serbia and to conduct a chorological and ecological analysis of this flora. The results of diversity analysis and summary distribution of steppe taxa were presented on 50 × 50 km grids using the Universal Transverse Mercator projection. Regression analysis was used to explore the relationship between steppe species richness and the altitude. Floristic similarity between the geographical groups were analysed using the clustering method and species fidelity to each cluster was calculated. The species conservation status is also presented. In total, the presence of 233 steppe taxa in the investigated area was recorded. The most frequent families are Asteraceae, Fabaceae, Poaceae and Caryophyllaceae with Dianthus, Astragalus, Allium, Stipa, Cytisus, Centaurea and Silene as genera that contribute the most to steppe flora in Serbia. According to the chorological and life form spectra, Pontic European taxa and hemicryptophytes are the most numerous. Geological substrate like loess, sand, and other unbound sediment, as well as the lower altitudinal ranges proved to be most suitable for the development of steppe flora in Serbia. The distribution of steppe flora in Serbia indicates Deliblato Sand and Mt Fruska Gora as centres of diversity. The study suggests that the cumulative effect of environmental factors is important to consider in the planning of steppe species conservation.

Türk Etnogenezi Meselesinde Neolitik-Tunç ve Demir Çağları’ndaki Kültürler Üzerine Bir Değerlendirme

Güney Sibirya bölgesi tarihin en erken devirlerinden itibaren insanlık için bir cazibe merkezi olmuştur. Geniş orman dokusuna sahip olan bölge aynı zamanda bozkır bitki örtüsü ve iklimine sahiptir. Bölgenin en önemli özelliklerinden birisi de akarsu ve ırmak bakımından çok zengin olmasıdır. Avcı-balıkçı-toplayıcı dönemden ziraat ve hayvancılığın gelişimine müteakip bölge farklı kültür dönemlerine ev sahipliği yapmıştır. Söz konusu bölge aynı zamanda Türklerin binlerce yıl yurt tuttuğu bir mekân olmuştur. Güney Sibirya’da görülen kültür çağlarının batı ile ilişkili olduğu ilim adamlarınca pek çok çalışmaya konu olmuştur. Avrupa-Asya kıta coğrafyasında üretimin başlangıcı diyebileceğimiz Neolitik döneme ait çok fazla kültür dönemi mevcuttur ve bu kültür dönemleri birbirleri ile ilişkilidir. Bu ilişkiler Ukrayna’dan Ural’a, oradan Sibirya istikametinde doğuya doğru Altay Sayan’a, Yenisey-Angara ve Baykal’a, güney istikametinde de Kazakistan’a ve Tanrı Dağları’na kadar takip edilmektedir. Bu izler Neolitik Çağ, Bakır Çağ, Tunç ve Demir Çağı boyunca tüm bu geniş coğrafyada arkeolojik, antropolojik ve etnografya bakımından incelenmektedir. Bu bakımdan biz Ukrayna’dan doğuya doğru Türklerin tarih sahnesinde ortaya çıktıkları ilk döneme kadar bu kültür çağlarının birbirleri ile ilişkilerini ortaya koymaya çalışacağız.

Floristic diversity of steppe territories near Poltava town (Ukraine)

Current progress in botany requires new claims for floristic research. Now the latter is not a simple species inventory of a separate local or regional flora but it needs coordination with recent results of critical taxonomic, nomenclatural and molecular phylogenetic investigations. Based on the fact that detailed research on steppes as a zonal type of vegetation in the Forest-Steppe zone of Ukraine is very important for preservation of current steppe territories, the authors studied several territories with steppe vegetation near Poltava town (Poltava region, Ukraine). The key steppe territories found are situated near Abazivka, Rozhayivka, Kostochky, Buhayivka, Machukhy, Ivonchentsi and Zhuky villages. Data about steppe flora from only the first territory located between Abazivka and Rozhayivka villages including “Rozhayivskyi” local botanical reserve were early reported in literature sources while data about steppe vegetation of the other areas has never been published in detail. The full list of 401 vascular plant species found on these steppe territories with the frequency of distribution, major synonym names and references to current taxonomic papers for separate species are proposed. One of these species (Hemerocallis fulva (L.) L.) is a new alien for Poltava region. Taxonomy for all species was critically revised, nomenclature of several taxa (Dichoropetalum carvifolia (Vill.) Pimenov & Kljuykov, Erophila verna (L.) DC., Campanula canescens (Waldst. & Kit.) Roth) is discussed in detail. The name “Dichoropetalum carvifolium-chabraei (Crantz) Soldano et al.” is an invalid designation based on trinominal and must be rejected. The names Selinum chabraei Jacq. ex Murray, Peucedanum euphimiae Kotov and Hemerocallis lilio-asphodelus var. fulva L. were lectotypified. The studied steppe territories have the great significance in the sozological aspect, they include 32 rare steppe plant species (seven from the Red Data Book of Ukraine and 25 from the list of locally rare plants within Poltava region) so the primary task for further research is to organize their protection as the most valuable steppe areas and the monitoring of their condition in the future.

THE STRUCTURE OF THE SIBERIAN GEOGRAPHICAL FLORAL ELEMENT IN THE MIDDLE SIBERIAN FOREST STEPPES

Background.The ultimate goal of studies of any flora is the clarification of the history of vegetation cover and individual taxa formation in the studied region, determination of the degree of its individuality, of floristic links with other territories, and of regularities in flora formation.Materials and methods.The flora of vascular plants in the island forest steppes of Middle Siberia, i. e. of the Krasnoyarsk, Kansk and Achinsk forest steppes, identified by the specific floras method of A. I. Tolmachev, was chosen as the object of research. The purpose of the paper was to study the structure of the Siberian geographical element in the steppe flora, characteristics of the types of constituent distribution areas selected on the basis of the phytochorion concept. The basis for determining the types of habitats was the planetary regionalization scheme by A. L. Takhtajan, complemented by statistical convergent zonation for Siberia by L. I. Malyshev, and for the Russian Far East by R. V. Kamelin.Results.The territory of the Middle Siberian forest steppes is a part of the Altai-Yenisei Province. The Krasnoyarsk, Kansk and Achinsk forest steppes (Krasnoyarsk Territory) are the most northern parts of the region (55°28’–57°28’N, 89°– 96°40’E). Twenty-six local floras were examined. Ten distribution area types were identified within the Siberian geographical element of the boreal group according to the names of sub-regions and provinces (154 species, 11.12%), limiting their distribution from West to East or from East to West, including all intermediate Siberian provinces between them. All types of distribution areas were combined into four large subgroups, namely Siberian, West Siberian, Middle Siberian, and East Siberian. Names of geographical elements were composed from the names of several phytochoria, in which they had been registered, according to the rules by M. G. Popov.Conclusions.The Siberian geographical element rates third in all three forest steppes after the Euro-Siberian and Circumboreal geographical elements. In the flora of the Middle Siberian forest steppes Siberian elements amount to 11%, among which the Middle Siberian ones prevail (4.4%, 61 species) due to the geographical position of the flora. The fraction of species distributed throughout Siberia is 3.25% (45 species), followed by East Siberian species (2.24%, 31 species) and West Siberian ones (1.23%, 17 species).

The Eurasian steppe belt in time and space: Phylogeny and historical biogeography of the false flax (Camelina Crantz, Camelineae, Brassicaceae)

Stretching 8000 km from the Pannonian basin and the Danube delta in the West to the Manchuria region in the East and reaching up to 1000 km in width, the Eurasian steppe belt is the vastest steppe region worldwide. However, our knowledge about the temporal and spatial patterns of floral origin and evolution of the Eurasian Steppe is limited and inconclusive. Case studies on typical steppe flora may help us close such gaps. The study subject of this project was Camelina – a taxon which occupies open dry habitats in temperate zones of Eurasia. To infer the evolutionary history of this genus, maximum likelihood optimisation in RAxML and Bayesian Inference approach were carried out, based on the nuclear external transcribed spacer region. Furthermore, we performed a secondarily calibrated time estimation analysis using Bayesian optimisation in BEAST to infer potential influence of climatic shifts and paleogeographic events on the distribution patterns of Camelina and carried out an ancestral area reconstruction analysis using a Bayesian Binary Method. Our study resulted in a well-supported phylogeny that corresponds with the species morphology and uncovered several genetically distinct inter- and intraspecific lineages which appear to correlate geographically. Time divergence estimation argue for the diversification of Camelina to have taken place in the Middle East around the transition from Pliocene to Pleistocene (3-2 mya), and its historical biogeography to have been under a strong influence of several glacial periods and their palaeoclimatic and palaeoenvironmental consequences. Its young age also explains the subtle morphological character differences among species and high interspecific hybridisation potential. We further discuss the rediscovery of wild Camelina sativa populations and propose the external transcribed spacer as a ribotype identifying region for young and rapidly evolving core eudicot lineages.

«HADIATSKYI» REGIONAL LANDSCAPE PARK FLORA GEOGRAPHIC STRUCTURE (POLTAVA REGION)

The article contains results of «Hadiatskyi» regional landscape park flora geographic structure due to the nature of species distribution in the latitudinal (zonal), belt (oceanic continental) and regional aspects, in accordance with the approaches of G. Moisel with co-authors. «Hadiatskyi» RLP flora is characterized by predominance of relatively wide floristic areographic types. According to zonal characteristics there distinguish 16 types, with predominance of species representing submeridional-temperature (177; 18,7 %) and submeridional-boreal (134; 14,2 %) areasamong them. The core of the park florais formed with species ofsubmeridional-temperature, meridional-temperature, submeridional-boreal, meridian-boreal, sub-temperature boreal areas, which make up 64% of the species diversity of the region flora and determine the flora floristic-zonal accessorynature. Climatic features of areas of the region flora are dominated by species with habitats tending to regions with a higher degree of oceanic climate. According to regional confluence and length of areas, there is species of European-Asian (383; 40,5%) and European (221; 23,3%) ranges dominance. The European-Asian group composition is much dominated by species with the European-Western-Asian distribution (195; 20,7%). Among the species whose habitats are associated with Europe, widespread species of European type (195; 20,6%) predominate. In general, geographical structure of «Hadiatskyi» regional landscape park flora corresponds to the western European steppe and steppe flora.

Divergence of Oxytropis Species from the Section Verticillares (Fabaceae) of Steppe Flora of Baikal Siberia Based on Analysis of Chloroplast DNA

The analysis of nucleotide sequence polymorphism of chloroplast DNA psbA–trnH, trnL–trnF, and trnS–trnG intergenic spacers in the Oxytropis lanata, O. myriophylla, O. oxyphylla, O. selengensis, and O. stukovii (section Verticillares) of the steppe flora of Baikal Siberia demonstrated that the populations are characterized by a high haplotype (0.634–1.000) and relatively low (0.0003–0.0045) nucleotide diversity. Statistically significant values of genetic distances between the populations of the same species change from 0.19382 to 0.43449. Marker nucleotide substitutions and indels were detected in O. lanata, O. gracillima, O. interposita, O. pumila, and O. mongolica, indicating a significant divergence of their chloroplast genomes. A weak differentiation (ΦST = 0.137, P < 0.0001) between O. oxyphylla, O. selengensis, O. stukovii and O. bargusinensis and also low values of genetic distances (0.08939–0.32339) (corresponding to interpopulation distances), absence of differentiating molecular markers, formation of a single haplogroup in the median network, and presence of common haplotypes indicate that these species are a genetically homogeneous group probably formed as a result of relatively recent and rapid divergence from the common ancestor, as well as a high degree of interspecies hybridization.

Morphological Innovations and Vast Extensions of Mountain Habitats Triggered Rapid Diversification Within the Species-Rich Irano-Turanian Genus Acantholimon (Plumbaginaceae).

The Irano-Turanian floristic region spans a topographically complex and climatically continental territory, which has served as a source of xerophytic taxa for neighboring regions and is represented by a high percent of endemics. Yet, a comprehensive picture of the abiotic and biotic factors that have driven diversification within this biota remains to be established due to the scarcity of phylogenetic studies. Acantholimon is an important component of the subalpine steppe flora of the Irano-Turanian region, containing c. 200 cushion-forming sub-shrubby pungent-leaved species. Our recent molecular phylogenetic study has led to enlarging the circumscription of this genus to include eight mono- or oligospecific genera lacking the characteristic life-form and leaves. Using the same molecular phylogeny, here we investigate the tempo and mode of diversification as well as the biogeographic patterns in this genus, to test the hypothesis that a combination of key morphological innovations and abiotic factors is behind Acantholimon high species diversity. Molecular dating analysis indicates that Acantholimon s.l. started to diversify between the Late Miocene and the Pliocene and the biogeographic analysis points to an Eastern Iran–Afghanistan origin. Macroevolutionary models support the hypothesis that the high diversity of the genus is explained by accelerated diversification rates in two clades associated with the appearance of morphological key innovations such as a cushion life-form and pungent leaves; this would have favored the colonization of water-stressed, substrate-poor mountainous habitats along the newly uplifted IT mountains during the Mio-Pliocene. Given the apparent similarity of mountain habitats for most species of Acantholimon, we hypothesize that its current high species diversity responds to a scenario of non-adaptive radiation fueled by allopatric speciation rather than evolutionary radiation driven by ecological opportunity. Similar scenarios might underlie the high diversity of other speciose genera in the topographically complex Irano-Turanian landscape, though this remains to be tested with fine-grained distribution and climatic data.

Taxonomic structure of local floras in Sidinskiy and Pribaitakskiy steppes (Krasnoyarsk region)

Sidinskiy and Pribaitakskiy steppes are the part of the Minusinsk province of the Altai-Sayan mountain country. On the territory of steppes 12 local floras (LF) were marked and examined using the same method. Studies were carried out according to the recommendations of A.I. Tolmachev (1931): identification of different types of ecotypes of LF, the full species composition of ecotypes (flora inventory), tracking the completeness of detection in LF. In the Sidinskiy steppe the number of families in the LF varies from 25 (Syida) to 43 (v. Alha), in the Pribaitakskiy steppe there is a big difference in the number of families in the LF from 31 (Krasnoyarsk reservoir, Tuba) to 65 (Mayak, Idra). The leading families in the local steppe flora are Asteraceae, Poaceae, Fabaceae. The Fabaceae family ranks third in the top of ten families in 50 % of LF, determining the type of flora as the Mediterranean-Central Asian (Fabaceae-type). Different types of LF allow to determine the type of all steppe flora as mixed, combining features of boreal (Asteraceae-Poaceae- type) and steppes flora (Fabaceae-type) with close ties with Central European floras (Rosaceae-type). 4 distinct levels of species richness are determined: 1 − 496-544; 2 − 408-413; 3 − 319-374; 4 − 279-298 species.