Free Niches Research Articles

Evaluation of symbiotic relationships of oral microorganisms and their effect on the development of inflammatory changes of the oral mucosa in the complete absence of teeth

Introduction. By fixing on the exposed surfaces of complete removable dentures and oral soft tissues, bacteria form a biofilm, thereby increasing their overall virulence and resistance. The microorganisms that make up the biofilm are often in a symbiotic relationship, which allows them to increase their pathogenic potential and cause the development of denture stomatitis. Accordingly, when a particular strain is present in the oral cavity, the risks of symbiosis are significantly increased. The aim of the study was to evaluate the effect of symbiotic relationships of oral bacteria on the development of inflammatory changes in the oral cavity in the absence of teeth. Materials and methods. Two groups of patients belonging to the elderly age according to WHO systematization (60–74 years) with complete absence of teeth (K08.1) were formed, differing in the presence of clinical manifestations of inflammation (82 men and 49 women). Biological material sampled from the oral cavity of patients was studied using the culture method and RT-PCR. To quantify the interaction between members of the microbiocenosis, we used the Jaccard similarity coefficient. Results. Coagulase-negative and coagulase-positive staphylococci, Neisseria, Candida spp., Enterobacterales and F. nucleatum were more frequently found in patients with complete absence of teeth. Expressed symbiotic relations between microorganisms of the Enterobacterales order, Lactobacillus, Neisseria and Corynebacterium genera, as well as S. salivarius, C. albicans, F. nucleatum were established. The nature of these relations depended on the presence of inflammatory changes in the oral mucosa and, in turn, influenced the development of the latter. Thus, in the absence of inflammation, Corynebacterium, Lactobacillus and S. salivarius showed stable synergism. In case of inflammation, the association between these bacteria was accompanied by the introduction of F. nucleatum and displacement of S. salivarius. Conclusion. Thus, conditionally pathogenic microorganisms, forming microbial associations with multidirectional symbiotic relations increase their virulence, which allows them to occupy free niches in the oral cavity and subsequently trigger the development of pathological process of inflammatory character of prosthetic bed tissues.

ТРЕНДВОТЧИНГ КАК СОВРЕМЕННЫЙ ИНСТРУМЕНТ ПОИСКА ПОТЕНЦИАЛЬНЫХ РЫНОЧНЫХ ВОЗМОЖНОСТЕЙ И ЭФФЕКТИВНЫХ БИЗНЕС-РЕШЕНИЙ

The article considers the place and role of trendwatching in modern business. First, a comparative analysis is done on the basic concepts with which the trend is identified (tendency, fashion, analytics, technological entrepreneurship). The basic classification of trends is carried out according to scalability, key areas of society, industry (market) affiliation, dominance of position and dynamism of development. The priority properties of the trend are determined: direction, strength, duration. It is emphasized that trendwatching is an important part of any innovation process, since it provides an opportunity to anticipate new technological, consumer and other trends. In general, trendwatching is increasingly becoming a tool for finding opportunities that contribute to successful competition in the 21st century market by forming a proposal based on potential user expectations, outpacing rivals operating in the industry under study, taking into account the influence of macro-environment factors and adequate adjustment by corporate management. To that end the author gives the methodology for determining the trend, an important place in which is occupied by the means (sources) of its research and selection. The issue of using the consumer trend matrix is discussed, which gives good results in finding free niches and contributes to the opening of new market windows, which is especially important for beginning business startups. At the end of the article, it is noted that the active use of trendwatching promotes technological entrepreneurship, and observing trends provides the business world with the necessary information, as a result of which it becomes more rational for companies to choose promising areas to increase their competitiveness and growth.

Globally invasive Potamopyrgus antipodarum (Gray, 1843) – an indicator of the degraded water systems in relation to native aquatic invertebrates

Global changes in climate and human impact favour invasions of aquatic organisms. Along with habitat modification, the abundance of invasive species might increase, leading to their greater impact on ecosystems functioning in disturbed areas. The appearance of species, which are drivers for ecosystem pollution are useful tool for the indication of some environmental changes in the area. We examine the occurrence of P. antipodarum populations, a global invader that established rivers, oxbow lakes, dam reservoirs, sand pits, gravel pits, and subsidence ponds in Poland (Central Europe). The research aims were to determine the extent of invasion in anthropogenically impacted habitats and the relationship between the abundance of aquatic invertebrates and oxygen concentration, pH, N-NO2, N-NO3, chlorides, and ammonia. This investigation helps elucidate the potential of invader to adapt to adverse environmental conditions in aquatic systems in which it was found dominant. The abundance of P. antipodarum showed an unimodal distribution, being higher in disturbed conditions. In snail communities it was a supereudominant or eudominant species in rivers, gravel pits, sand pits and subsidence ponds. Its relative abundance was the highest in gravel pits, in which it constituted more than 50 percent of benthic fauna. We demonstrated that environmental disturbances and pollution increase the vulnerability of water biocoenoses to invasions and the origin of free niches and that P. antipodarum is an indicator of degraded water systems. Results support the management of aquatic systems colonized by invasive species and highlight the need to assess the level of pollution discharged to prevent their dispersion. Management priorities must include the reduction or halt of invader spread because new aquatic environments are and will be created in industrial areas of the world.

Characteristics of spread and restoration of Pinus cembra L. in the Chornohora massif of the Ukrainian Carpathians

During the previous century, natural stands of Pinus cembra suffered significant losses due to the unreasoned methods of forestry, animal husbandry, cultural traditions of the local population, and the way of land possession in the Carpathian region in the past socio-political realities. The largest losses have occurred in the smallest habitats of P. cembra in the Chornohora massif. The case study in this part of the Carpathians involved changes of demographic parameters of Swiss stone pine population due to restoration succession processes in its habitats. Possible effects of climate change are also considered. Current trends in the population dynamics of Swiss stone pine indicate certain positive changes that have taken place over the past few decades, mainly after the introduction of some environmental regulations. Grazing pressure reduction in the highlands of the Carpathians should also be considered positive. At the same time, its complete cessation may have negative consequences for the restoration of the Swiss stone pine habitats within its former historical boundary. Necessary condition for recolonization of the lost territories by P. cembra is the presence of free niches at the upper forest or subalpine zones, where its ecological and biological advantages over spruce are fully realized. Another important factor is the optimal ratio between the number of Nucifraga caryocatactes and the number of fruit-bearing trees in the "mother" population. The most active recovery of P. cembra occurred at the beginning of the restoration succession in shrubby and herbaceous patches. At present, the intensive spread of Picea abies and Pinus mugo is an obstacle to the expansion of its population range. The impact of climate change on the restoration of Swiss stone pine is not obvious, as prolongation of the growing season enhances competition with other tree species while the timberline raises higher hypsometric levels.

Latin America and the European Union: Conceptual Approaches and Practice of Economic Cooperation

The article deals with North - South cooperation between the European Union (EU) and Latin America and the Caribbean (LAC) with an emphasis on bilateral trade. Over the past decades, cooperation with the EU has been perceived in LAC as a counterweight to the US dominance and one of the priorities of external economic relations. The article presents a retrospective of theoretical approaches of the non-Western Latin American school of UN Economic Commission for Latin America and the Caribbean (ECLAC, CEPAL in Spanish) to the economic cooperation with the EU. A feature of the article is the study of trade interaction between the LCA and the EU countries. When analyzing the dynamics of trade during the first two decades of the 21st century the author of the article comes to the conclusion that the trade exchange between the EU and the LCA is uneven. There are many LAC countries that continue to export low-value-added products to the EU. Thus, the dichotomy between two models of commercial specialization of LAC has exacerbated. On one hand, there is a model of South American countries focused on raw materials (MERCOSUR, Andean Community), and, on the other hand, there is a model that includes the export of manufactured products and participation in industrial production chains (Mexico, Central America). The article concludes that MERCOSUR will probably face a number of trade challenges related to its model of economic globalization, particularly with regard to its export specialization in commodities and food. The relevance of the study is due to the fact that in the context of exacerbation of geopolitical contradictions and a changing world order, it is important to analyze the Latin American approach to economic cooperation with the EU countries, among which, in turn, there is a growing understanding that still free niches in the Latin American market can be occupied by China or other partners not belonging to the collective West.

Glocal tnc product strategies in the international business management system

It is defined in this paper that the glocal business strategy enables the companies to strengthen their competitive position, attract customers and raise brand awareness, adapting their offer to each individual country and local scenario, while maintaining the emphasis on scale and global dimension. Glocalization strategy means the creation and distribution of products and services designed for the global or international market, and the ability to adapt them to local conditions. According to the objective of the paper, the peculiarities of the Ukrainian non-alcoholic beer market current state is defined as well as the substantiation of the commodity strategies development directions of transnational companies in the Ukrainian beer market, in particular on the segment of non-alcoholic beer for women, is proposed. Analysis of non-alcoholic beer supply in the domestic market revealed that the portfolio of the largest producers does not include craft non-alcoholic beer and beer, the taste of which would suit the tastes of youth and women's segments. The developed positioning scheme according to the price and taste characteristics of non-alcoholic beer offer in Ukraine revealed free niches in this category, especially beer with the taste of berries, fruits, aromatic herbs and spices. In addition, the niche of craft beer is free. Such product offers may be of interest to young people and women who do not like the smell of malt beer and its bitter taste. Taking into account the results of the survey and the conducted research, it is recommended that multinational companies adapt their product strategy by developing the segment of non-alcoholic beer for women. A strategy of positioning beer for women according to such characteristics as the content of required essential vitamins and microelements is proposed. The implementation of the proposed glocal product strategy will strengthen and increase the market share of the multinational company in non-alcoholic beer market due to the application of horizontal differentiation strategy by expanding the range of non-alcoholic beer flavors and vertical one by attracting consumers of different price segments.

Transformation of food security of the border region in the face of external challenges: a case study of Kaliningrad Oblast

Foreign trade relations of Russia in the 2010s developed in the context of various geopolitical challenges, which led to a radical transformation of the volume and geography of export-import operations, including the food sector. The 2014 embargo triggered an intensification of the import substitution policy in the Russian agriculture and food production. The value of the import component in the food market, the basic level of agriculture and food production development, and the level of diversification and localisation of raw material relations of enterprises acted as differentiating factors in the influence of new external challenges on the food security of the regions. Kaliningrad Oblast is of particular interest for studying the transformation of food security, taking into account the exclave position, the low level of agriculture development a decade ago, close export-import relations with European countries until 2014. The paper calculates food security indicators, analyses territorial and sectoral shifts in agriculture and food production, and estimates changes in the import component in the food market of Kaliningrad Oblast. The data of the federal state statistics service, the Kaliningrad regional customs, as well as the results of expert interviews and visual observations conducted by the authors in August 2020 are used. It was revealed that the transformation of food security in Kaliningrad Oblast, on the one hand, reflected national trends, and, on the other hand, had unique features. The latter were characteristic of changes in the food independence of the region. Its increase was associated with the rapid growth of agriculture with a high return of government support. In addition, there was a relatively dispersed distribution of key centers of agricultural production, atypical for many regions of “mainland” Russia. The beneficiaries of the free niches on the market, which opened after the food embargo in 2014, as in most of the territory of Russia, were large agroholdings, but many of them, in contrast to those located in the interior regions of the country, were rather acutely experiencing the ruptures of raw materials ties.

Are the Food Embargo and Import Substitution Changing Regional Production? A Case Study of Leningrad Oblast

—In the 2010s, in Russia, many conditions for the development of agriculture and the food industry changed, having experienced the consequences of the 2008 and 2014 crises and import restrictions on certain types of agricultural products and food from the EU and other countries. In Russia’s state political agenda, attention to food security has increased and the import substitution policy has intensified. Using the example of Leningrad Oblast, a region located in the zone of influence of the largest agglomeration and neighboring EU countries, the article attempts to answer the questions of who became the true beneficiaries of the food embargo and to what extent external influences have altered the sectoral and territorial structure of food production and to what extent they made it possible to overcome the local context—increase production in peripheral areas. The 2014 food embargo opened up colossal free niches in the market of St. Petersburg, with a population of 5 mln. The analysis showed that there were no fundamental changes in the sectoral structure, but in absolute terms, vegetable production increased significantly, which is directly related to the change in competition due to the food embargo and improvement in credit policy conditions. The dependence of the territorial structure of agriculture on the state of the largest enterprises increased. However, no fundamental changes have been observed in the production of certain food products. The reasons for this are a decrease in demand due to a drop in purchasing power of the population during crisis periods, an insignificant raw materials base in the region, the use of new opportunities by enterprises in St. Petersburg itself, filling the market with goods from neighboring regions and imported products from non-EU countries, owing to its seaside position and presence of a port.

Аллелопатическая напряженность биотопов в лесных экосистемах влажных субтропиков

In the absence of a pronounced anthropogenic impact, allelopathic tension in forest ecosystems of the main formations of the Sochi Black Sea region and its influence on the saturation of phytocenoses with an adventive plant group are analyzed. The studies were carried out in 38 forest ecosystems of 7 formations at 13 stationary sites in the foothill zone. The absence of anthropogenic load was determined by the average bulk soil mass and the class of atmospheric air pollution. The аllelopathy environment of individual trees was assessed according to the activity of the forest floor of 21 tree species recorded in the analyzed forest communities. The tension of biotopes in ecosystems was assessed with the joint growth of 1 to 5 tree species in the main canopy. The activity of water-soluble colins was determined by biotesting of water extracts from forest litter according to A.M. Grodzinsky. The activity of the solutions was assessed by the index of allelopathic activity. It is shown that the magnitude of the contribution of the influence of phytocenosis to the allelopathic background of the biotope depends on the species-specific features of the stand and the manifestation of a synergistic or antagonistic effect of аllelopathy related to the level of species completeness of communities. An increase in species completeness to 0,4-0,6 is accompanied by an increase in the synergistic effect, a decrease in the intensity of the аllelopathic background and saturation with adventive species, with their proportion increasing by 11,9-21,5%. An increase in the species completeness by more than 0, 6 is statistically reliably accompanied by a decrease in the synergistic effect and a transition to antagonism, with an increase in allelopathic tension in the community, increasing the proportion of native species, reducing the number of free niches for adventive species and the level of vulnerability of communities to their introduction and distribution.

Generation of donor organs in chimeric animals via blastocyst complementation.

The lack of organs for transplantation is an important problem in medicine today. The growth of organs in chimeric animals may be the solution of this. The proposed technology is the interspecific blastocyst complementation method in combination with genomic editing for obtaining “free niches” and pluripotent stem cell production methods. The CRISPR/Cas9 method allows the so-called “free niches” to be obtained for blastocyst complementation. The technologies of producing induced pluripotent stem cells give us the opportunity to obtain human donor cells capable of populating a “free niche”. Taken together, these technologies allow interspecific blastocyst complementation between humans and other animals, which makes it possible in the future to grow human organs for transplantations inside chimeric animals. However, in practice, in order to achieve successful interspecific blastocyst complementation, it is necessary to solve a number of problems: to improve methods for producing “chimeric competent” cells, to overcome specific interspecific barriers, to select compatible cell developmental stages for injection and the corresponding developmental stage of the host embryo, to prevent apoptosis of donor cells and to achieve effective proliferation of the human donor cells in the host animal. Also, it is very important to analyze the ethical aspects related to developing technologies of chimeric organisms with the participation of human cells. Today, many researchers are trying to solve these problems and also to establish new approaches in the creation of interspecific chimeric organisms in order to grow human organs for transplantation. In the present review we described the historical stages of the development of the blastocyst complementation method, examined in detail the technologies that underlie modern blastocyst complementation, and analyzed current progress that gives us the possibility to grow human organs in chimeric animals. We also considered the barriers and issues preventing the successful implementation of interspecific blastocyst complementation in practice, and discussed the further development of this method

ТЕНДЕНЦІЇ РОЗВИТКУ ПІДПРИЄМСТВ РЕСТОРАННОГО ГОСПОДАРСТВА У ЧЕРНІВЕЦЬКІЙ ОБЛАСТІ

Abstract Introduction. The high level of the restaurant business profitability along with its riskiness makes it possible to consider it as a promising sector of development, especially in regions where there are free niches. Significant dynamism of changes in the external environment of this industry in comparison with others necessitates continuous information monitoring. The purpose of the article is to determine the current state of the restaurant industry of Chernivtsi region and to outline perspective directions of its development in the current conditions. Results. The contents of the «restaurant industry» concept and its evolution are considered. It is determined that the modern tendencies of its development are caused by the formation of a market economy with a focus on leisure organization. An dynamics analysis of the restaurant services market in Ukraine is presented. Market analysis of Chernivtsi region has been given. The role of this branch in the region economy is determined. The employment dynamics in the field of temporary accommodation and catering of Chernivtsi region is analyzed, and the forecast of the considered indicator till 2020 is developed. The dynamics analysis of gross value added and output of the research industry for the years 2014-2017 is carried out, which allows to confirm the stable growth, which for the whole period amounted to 41.1% of output and 37.5% of value added. Conclusions. The key development tendencies of the restaurants in the Chernivtsi region are identified: unsaturation of the market and positive trends of growth make it possible to consider it as promising, despite the low population level, trends in employment dynamics make it possible to consider it as a promising source of new jobs, dynamics of output and gross value added testify to the growing demand for restaurant business services, despite the relatively low standard of living. Proposed directions of restaurant market development in Chernivtsi region are offered: price democratization, tourism orientation with preservation of authenticity, deepening of specialization, expansion of entertaining and cognitive services, catering, automation of business processes and online sales. Key words: restaurant industry, restaurant, restaurant market, restaurant business, coffee shop, types of coffee shops, coffee market.

Comparing the respective transmutation mechanisms of Patrick Matthew, Charles Darwin and Alfred Wallace

A comparison of the evolutionary mechanisms of Patrick Matthew, Charles Darwin and Alfred Wallace highlights their differences. In Matthew’s scheme, catastrophes initiate periods of radiation and speciation until a fully stocked environment enters into stasis. Catastrophes first need to exterminate competing species before the survivors can radiate into free niches and diversify into new species. In Darwin’s early theory, conditions of life, such as those prevailing under domestication, first need to increase the variability of a species before natural selection can transform it. In Darwin’s mature theory, competition replaces conditions as the main drive behind evolutionary change, and sympatric speciation becomes possible. Wallace’s theory differs from both Matthew’s and Darwin’s. Interspecific competition is not a brake halting transmutation (as in Matthew’s theory) nor is intraspecific competition a sufficient drive for it. Although each theory integrated natural selection with variability, competition and changed conditions in distinct ways, each allowed for species transmutation somehow. The result was similar (transmutation), but the mechanisms yielding that result (the integration of natural selection with variability, competition and change in conditions) differed significantly.

How apomictic taxa are treated in current taxonomy: A review

AbstractGametophytic apomixis (asexual seed formation without syngamy of female and male gametes) is a highly interesting mechanism for researchers in plant biotechnology, genetics, evolutionary biology, and taxonomy. Apomixis evolved repeatedly and independently in the evolution of multiple genera. It is an effective reproduction barrier and, consequently, conserved apomictic genotypes may become overrepresented in nature. Apomictic plants may easily colonize free niches with only one or a few individuals and outcompete outcrossing plants. In spite of the indisputable pros of asexual reproduction, apomixis also has several cons. One of the most commonly mentioned is the accumulation of deleterious mutations in asexual lineages and decreased genetic variation. However, apomicts in general can be genetically highly diverse. The most common sources of this variation are the accumulation of mutations, hybridization with sexual plants, and facultative apomixis. Facultative apomicts are highly variable in their level of residual sexuality, which increases their genotypic and phenotypic variation. Even in the case of obligate apomicts, gene flow is possible due to functional male meiosis and the production of viable pollen grains by apomicts. Apomixis occurs in plant genera in which hybridization together with polyploidization play an important role in diversification and causes severe problems in taxonomy. How to accommodate apomictic taxa in taxonomic treatments, and understanding what should and what should not be referred to as a species are intriguing questions. This review aims to provide an overview of the main characteristics of “apomictic genera” and the approaches used to treat apomictic taxa within these genera. To achieve this aim, the review was divided into several parts. Firstly, the distinctive features of apomictic reproduction and apomictic taxa are described together with issues related to the taxonomic evaluation of apomictic taxa. The second part discusses approaches in the known apomictic genera, and the final part presents the authors’ view on important points, which need to be taken into account in the classification of apomictic taxa.

Enigmatic adult overwintering in damselflies: coexistence as weaker intraguild competitors due to niche separation in time

AbstractOdonata, like most freshwater invertebrates, tend to overwinter in water due to the thermal properties of a water environment. Winter damselflies (genus Sympecma), however, hibernate as adults in terrestrial habitats. The strategy of adult overwintering combined with high mortality is associated with several unique adaptations to semiarid conditions, but winter damselflies maintain this unique life history throughout almost the entire Palaearctic. We assume that the unique strategy of adult overwintering in temperate zones is indirectly maintained by niche separation in time. We used phenological data from the Czech Republic to compare the seasonal phenology of Sympecma spp. with other coexisting odonate species. Seasonal population growth patterns between S. fusca and other coexisting species representing different life histories were compared using GLMMs and LME. The models showed negative non‐linear dependence between the population growth of S. fusca and the estimated abundance of compared species. We found that the specific strategy of adult overwintering makes it possible to avoid seasonal maxima of competition and predation in adult and larval stages. Adults may benefit from free niches during spring while larvae may benefit from size advantage among intraguild competitors and optimal conditions for development.

Fast Growing Firms ("Gazelles") and the Evolution of Russian Economy

The article is based on the empirical study of fast growing firms ("Gazelles") in Russia. Sales volumes of many such firms are growing in accordance with the precise exponential trend with surprisingly high quality of approximation. The author finds strong links between this phenomenon and the concentration of most of "Gazelles" in market niches where demand limitations are practically non-existent. Conscious, purposeful entrepreneurial search of free niches becomes under described conditions an important addition to the classic mechanism of evolution of the economy through the natural selection of random changes. The author’s approach to these processes is based on a modification of the well known Lotka-Volterra model.

Competition and complementarity of retailing in the historic city centre of Vienna

The purpose of this study is to explore the effects of competition and complementarity on retailing in the historic city centre of Vienna and to analyse the changes brought about by these mechanisms. This concerns the status of Vienna’s city centre as a prime shopping location and the way this position has been undergoing significant changes. But it also concerns the structures and spatial organisation of retail in this main shopping district. The study itself is based on a survey of a sample of about 2000 shops.Three indicators serve as a basis to analyse the effects competition and complementarity have exerted on the retail premises: retail sectors, chain operation and store sizes. On a spatial level, the analysis is based on the functional units that constitute the historic city centre of Vienna.In the historic city centre of Vienna fierce competition among retailers is bringing about a reduction of the number of competitors but not a decrease in the number of retail premises. Nationally and internationally operating chains are the ‘driving forces’ of restructuring retailing and its related spatial patterns. Other retailers are forced to find free niches or market segments, which are defined by the principle of complementarity to retail sectors, retail forms or locations of national or international chain stores. The study comes to the conclusion that the effects of competition and complementarity cannot be explained in their totality, but they have to be interpreted as to the impact they have on the spatial organisation of the city. The competition between large-scale multinational chains is the source of the dynamic process that keeps transforming the entire retail trade in downtown Vienna. This process is regarded as crucial for the vitality of retailing in the city centre, as supplementary retail structures in surrounding neighbourhoods are provided with new opportunities and niches. The dynamics triggered by multinationally operated chain stores, are mutually related to the emergence of highly specialized supplementary zones adjacent to the main shopping streets. The larger retail formats in the main shopping area vice versa benefit from the specialised supplementary zones, which respectively contribute to maintaining the high standards of the Main Shopping Area but also to supporting the city as a prime shopping location, even though the observed restructuring of retail is converting the historic city centre into a themed destination for leisure shopping.

Revision of the genus Peraeospinosus Sieg, 1986 (Crustacea: Peracarida: Tanaidacea)

Ten species, four new to science, five formerly belonging to genus Typhlotanais, and Peraeospinosus pushkini (Tzareva, 1982) are congeneric species, based on the following set of characters: a row of setae is present on the dorsal margin of the cheliped carpus, the distal seta of pereopods 4–5 exceeds the bifurcated unguis, large prickly tubercles on pereopods 4–6 surrounded by well‐calcified spines, the pleopods semi‐elliptical, and the rami of the uropod subequal in length. The new definition of the genus is proposed together with a key for identification of the females. The present‐day distribution of the genus does not in itself indicate geographical origin, although the possibility of a deep‐water origin cannot be excluded. It is assumed that phylogenetically young, blind Peraeospinosus could have colonized Antarctic free niches and then radiated.

Famennian and Tournaisian recoveries of shallow water Rugosa following late Frasnian and late Strunian major crises, southern Belgium and surrounding areas, Hunan (South China) and the Omolon region (NE Siberia)

The Rugosa remained almost totally absent from the platform environments of southern Belgium and surrounding areas, Hunan and Omolon during the long time interval between the end-Frasnian crisis and the early part of the late Famennian ( marginifera Zone), probably owing to cool climatic conditions. They first reappear in the Upper marginifera Zone, but are uncommon and poorly diversified. Few of them belong to pre-Famennian genera. It is only near the beginning of Strunian time that rugose corals radiated and became common. Their morphological and allometric variabilities were very large, indicating their high potential for adaptation to free niches. This first radiation was abruptly terminated by an extinction event, and a second radiation quickly began, mainly from new taxa and only from a few previously known ones. In western Europe and in Hunan, this second radiation was also stopped abruptly, while species were evolving, by the Hangenberg event at the end of the Strunian. In Omolon, where the position of the Devonian–Carboniferous boundary is doubtfull, the second radiation may have been completed before the end of the Strunian, and probably the corals affected by the end-Famennian event were new ones, resulting from a third radiation. In the three regions and at each recovery, the rugose corals are endemic, indicating that marine connections were poor. After the Hangenberg event, surviving Rugosa reappeared almost immediately (except in South China) and were widespread, indicating good marine connections. However, they remained poorly diversified, sometimes until the late Tournaisian. The two major extinctions (end-Frasnian and end-Famennian) and the Strunian ones were responsible for the major taxonomic differences between pre-Famennian and post-Famennian Rugosa.

The beech (Fagus L.) in western Eurasia–an actualistic approach

AbstractFloristic investigations in the western Eurasian area of Fagus L. were carried out to provide a basis for comparison with European Late Tertiary plant assemblages containing Fagus. Beech turned out to be part of polydominant forests in marginal regions of its range. It is of interest that Fagus occurs together with a number of evergreen species not only in the well known Tertiary relict areas of Northern Turkey and western Georgia, but also in Southwestern Europe. Coastal stands in the Georgian Colchic area with high atmospheric humidity turned but to be most significant for the actualistic approach. Small‐scale mosaic patterns of distinct vegetation units could be observed. They are caused by differences in soil drainage and fluctuating ground water levels. Such conditions are supposed to be very similar to Neogene vegetation types reflected in the fossil record.Spontaneous spreading of exotic plants in Georgian mixed broadleaved evergreen forests but also in southern Switzerland demonstrates the abundance of free niches in contemporaneous broadleaved forests. Climates with evenly distributed high amounts of annual precipitation and no severe winter and late frosts seem to favour such phenomena.Monodominant beech forests are derived vegetation types of the postglacial period and occur throughout the whole area of Fagus in western Eurasia.