scholarly journals Generative reproduction efficiency and the population age structure of Rumex confertus Willd.

2012 ◽  
Vol 59 (2) ◽  
pp. 85-93 ◽  
Author(s):  
Tomasz Stosik
Keyword(s):  
Alien Species ◽  
Population Size ◽  
Age Structure ◽  
Vegetation Cover ◽  
Vegetative Reproduction ◽  
High Coverage ◽  
Major River ◽  
River Valleys ◽  
Reproduction Efficiency ◽  
Periodic Reduction

<i>Rumex confertus</i> is one of the alien species vigorously entering native meadow as well as ruderal communities in major river valleys. In about a hundred years the species invaded almost the whole territory of Poland. Many reports stating that Russian Dock may reach high coverage in various phytocoenoses contradict those of its low generative reproduction efficiency. In communities where it most frequently occurs, germination is hindered by the lack of empty spaces. In such conditions the population size remains stable due to vegetative reproduction. Only hay-growing meadows seem to promote the influx of new genets into population, which is likely associated with vegetation cover removal and periodic reduction of competition from other species.

Showing the vegetation cover of flood-plains and river valleys on the Vegetation Map of Kazakhstan and middle Asia

1995 ◽  
pp. 58-66
Author(s):  
N. M. Kalibernova
Keyword(s):  
Plant Communities ◽  
Vegetation Cover ◽  
Flood Plain ◽  
Vegetation Map ◽  
Flood Plains ◽  
Additional Information ◽  
Ground Waters ◽  
The Matrix ◽  
River Valleys ◽  
Former Ussr

The fragment of the legend of the map concerning the vegetation of flood- plains and river-valleys in the subzones of northern and southern deserts is presented in the article. The map is compiled in Department of Vegetspon Geography and Cartography of Komarov Botanical Institute by a large team of botanists-geographers of the former USSR. The nature environments determining the development of vegetation of river-valleys in arid climate are conditioned by the intrazonal factors (alluvial and flood processes) at the background of natural zonal factors. Contrasts of environments and corresponding plant communities manifest themselves first of all. Mineralization of ground waters, salinity of soils, including the alluvial ones, are of essential importance. The practice of vegetation mapping of unstable habitats, to which floodplain landscapes belong, has shown that units of phytocoenological classification is of little use for this purpose. The heterogeneity of vegetation, consisting of short-term unstable serial communities generates a need for typification of space combinations of such phytocoenoses. For this purpose it is convenient to use generalized ecological-dinamic series, including plant communities of all levels within the limits of definite segment of valley. These series are the mapping units on the map. The vegetation of the first terrace is also nessecary to include in a single series with flood-plain vegetation because it has supplementary influence of ground waters. The higher divisions of the legend are based on zonal characters: vegetation of valleys in northern, middle and southern deserts. 13 numbers are used to show the vegetation cover of flood-plains and valleys. Additional 7 numbers are used for the out-of-valley meadow vegetation. The content is enriched by using of the letters by the numbers showing the geographic variants of series and ciphers for combination of series and out-of-series communities. The text legend is supplemented by the matrix (table), showing the subordination of subtitles, zonal position and geographic distribution of divisions. The types of series in the matrix are listed with indication of the main dominant species that gives the additional information on the legend divisions. The author's conclusion is that valley vegetation reveals clearly the zonal features, correlating with zonal (desert) vegetation.

Detection and representation of the basic peculiarities of vegetation cover by the mapping method (experience based on a research of goltsy-taiga territories)

2013 ◽  
pp. 32-47
Author(s):  
S. V. Osipov
Keyword(s):  
Vegetation Cover ◽  
Mapping Method ◽  
Vegetation Changes ◽  
Large Classes ◽  
High Rise ◽  
The Third ◽  
Altitudinal Belts ◽  
The One ◽  
Dynamic Series ◽  
River Valleys

Geobotanical mapping of the territory in riverheads Bureya of 4500 sq.km is carried out and the map of a actual vegetation cover of scale 1 : 200 000 is prepared. The legend of the map is presented in the form of the text with three-level hierarchy of classes. At the heart of structure of a legend of the map such regularities of a vegetation cover, as its latitudinal zonality / altitudinal belts, situation in a relief and dynamic series lie. The largest divisions of the legend reflect, first, change of large classes of mesocombinations of vegetation at the level of belts and, secondly, distinction in a boreal - forestry belt between a vegetation cover of tops and slopes of mountains, on the one hand, and the bottoms of river valleys, with another. Divisions of the legend of the second level reflect, first, vegetation changes in the form of high-rise and barrier changes of subbelts, secondly, distinctions of a vegetation cover in different geomorphological conditions (small and average river valleys, northern slopes, etc.). Divisions of the legend of the second level correspond to dynamic series of units of the third level. Essential addition to it are block diagrams of dynamics of a vegetation cover.

The large-scale vegetation maps of the western coast of Peter the Great Bay (Far East, the Sea of Japan)

2000 ◽  
pp. 50-61 ◽  
Author(s):  
S. V. Osipov ◽  
V. P. Verkholat
Keyword(s):  
Vegetation Cover ◽  
Large Scale ◽  
Far East ◽  
Peter The Great Bay ◽  
The Sea Of Japan ◽  
Western Coast ◽  
Spatial Unit ◽  
Peter The Great ◽  
Great Bay ◽  
River Valleys

Two territories on the western coast of Peter the Great Bay were mapped in the large scale. The geobotanical mapping means revealing and displaying the essential regularities of vegetation cover. Both the spatial and temporal regularities of vegetation under natural and anthropogenic influences are well pronounced in the territory under consideration. The concept of the vegetation spatial unit (vegetation complexes) was applied as a basis for mapping. The maps and their legend were worked out as a system of vegetation combination types (vegetation combination is a spatial unit of the supracoenotic level). Such categories, as vegetation of tops and slopes, lowlands and river valleys, sea coasts reflect maximal contrasts in vegetation cover, so they are the highest level divisions of the map legend. Types of succession series and stages of series are developed for construction of the second and third levels of the legend. Communities, similar in ecotope, total species composition, saplings and some other characteristics, are referred to one type of series. 5 types of series have been distinguished: dry, fresh, moist, very moist, wet. The main factor of dynamics in considered territory is fire and the series are mainly pyrogeneous. Series are presented as sequences of vegetation stages. The vegetation stages for tops and slopes are: closed low forest — open low woodland — shrub thicket with saplings — meadow with saplings, for lowlands and river valleys they are: open low woodland — thicket of saplings — meadow or mire with saplings.

scholarly journals Statistical Estimation of Modern Trends and Prospects of the Size and Structure Population of Ukraine

2017 ◽  
pp. 65-72
Author(s):  
Z. О. Palian ◽  
I. H. Bondarenko
Keyword(s):  
Population Size ◽  
Age Structure ◽  
Structural Changes ◽  
Age Groups ◽  
Natural Increase ◽  
Reproductive Age ◽  
Structural Factors ◽  
Forecast Horizon ◽  
The Crimea ◽  
Size And Structure

A balanced change in demographic processes should be considered as a prerequisite and, at the same time, as a result of the stable development of the state. Reproduction intensity depends not only on the character of demographic behavior, but also on the presence of contingents of the population, providing or potentially able to provide for its replacement. The dynamics of Ukrainian population, the transformation of its gender-age structure during the period of independence, taking into account the intensive and structural factors of natural increase and migration, is considered. During 2002-2015, the regime of survival and fertility improved in Ukraine, due to which the depopulation slowed down somewhat. But even these positive changes do not compensate for the loss of population size as a result of systematic aging, reducing the proportion of reproductive contingent and its aging. Significant demographic losses, direct and indirect, were caused by a hybrid war from Russia. Alienation of the territory of the Crimea and parts of Donbas is not only a minus 2.5 million citizens of Ukraine. This is a change in the structure of the population - a decrease in the proportion of older age groups that increase the demographic load and worsen the characteristics of survival and fertility of the maternal generation. In this work are presented the results of the short-term simulation of population size and structure taking into account modern trends of replacements components and existing administrative-territorial changes. Two scenarios of the forecast for 2018 have been developed, and the base year it was taken in 2013, when the Crimea was part of Ukraine. The first, realistic scenario was based on the preservation of the current situation - Ukraine without the annexed Crimea and the occupied part of the Donbas. The second scenario imitates the return to Ukraine of all the lost territories. Simulation showed that the population of Ukraine will be reduced by both scenarios, but to 41.9 million people under the scenario without the occupied and annexed territories and to 44.7 million people in the second scenario. The finish of war will due to slow down the death rate to 14.9%0. The age structure of the population does not differ significantly in two scenarios, because the forecast horizon is very short (4 years). The share of generation of parents and women of reproductive age in both variants of the forecast decreases. However, in the case of returning Crimea, it will be even lower (47.4% vs. 47.5% in the first scenario). The reason for this is the emigration of young and middle-aged people to the mainland of Ukraine and to the Russian Federation, which provided some preferences to the settlers from Ukraine. Expected structural changes combined with the modern life and fertility regime will worsen natural population growth rates in both scenarios. In further research is planned to build trend models of births and deaths that will allow the artificially restore the interrupted time series due to administrative-territorial incomparability of data on demographic events

scholarly journals The inventory of vegetation cover of small river valleys in the north-east of the Samara Region

2021 ◽  
Vol 10 (1) ◽  
pp. 157-162
Author(s):  
Vera Valentinovna Solovieva
Keyword(s):  
Plant Species ◽  
Vegetation Cover ◽  
Higher Plants ◽  
Small River ◽  
Wild Plants ◽  
Small Rivers ◽  
North East ◽  
The North ◽  
The Right ◽  
River Valleys

The study covered 10 small rivers in the North-Eastern part of the Samara Volga region. The author studied the vegetation cover, which is understood as a set of phytocoenoses and their constituent plant species. On the territory of Pokhvistnevsky District, there are two groups of river valleys that are heterogeneous in geobotanical terms. The first group includes the rivers with forested valleys (Kutlugush, Murakla, Karmalka). Their slopes are more or less symmetrical and steep. The vegetation cover of an undeveloped floodplain is usually uniform, and there is usually no belt. The valleys of the second group are treeless; their slopes are sharply asymmetrical (Amanak, Tergala, Talkish). The right-bank tributary of the Maly Kinel River the Lozovka River with its length of 20 km and the left tributary Kuvayka River with its length of 16 km were studied on the territory of Kinel-Cherkassky District. The Padovka and Zaprudka rivers and the right tributaries of the Bolshoi Kinel River (Kinelsky District) were also studied. The most common associations are (Salix fragilis heteroherbosa, Scirpus sylvaticus purum, Agrostis stolonifera Amoria repens, Elytrigia repens + Poa angustifolia heteroherbosa). In total, 19 types of phytocoenoses were noted, 4 of them are found in half of the studied rivers. In the plant communities of small river valleys there are 232 species of higher wild plants, which belong to 139 genera from 48 families. This is 60% of the total number of higher plants registered in the flora of small river valleys of the Samara Region. Rare protected plant species are registered here: Adonis volgensis Steven ex DC., Cacalia hastata L., Delphinium cuneatum Stev. ex DC., Globularia punctata Lapeyr.

Response of Daphnia population size and age structure to predation

1975 ◽  
Vol 19 (4) ◽  
pp. 2898-2905
Author(s):  
Nelson G. Hairston ◽  
Robert A. Pastorok
Keyword(s):  
Population Size ◽  
Age Structure ◽  
Daphnia Population ◽  
Size And Age Structure

Cryptosporidium parvum in Korea: Prevalence in Individuals Residing in Three Major River Valleys and Genetic Characteristics of the Isolates

2010 ◽  
Vol 72 (2) ◽  
pp. 167-172 ◽  
Author(s):  
Hyeng-Il CHEUN ◽  
Shin-Hyeong CHO ◽  
Yi-Young LIM ◽  
Byung-Chul LEE ◽  
Jung-Yeon KIM ◽  
...  
Keyword(s):  
Cryptosporidium Parvum ◽  
Genetic Characteristics ◽  
Major River ◽  
River Valleys

scholarly journals The role of rivers and streams in the migration of alien plants into the Polish Carpathians

2011 ◽  
Vol 23 (1) ◽  
pp. 43-56 ◽  
Author(s):  
Adam Zając ◽  
Barbara Tokarska-Guzik ◽  
Maria Zając
Keyword(s):  
Alien Species ◽  
Alien Plants ◽  
Anthropogenic Factors ◽  
Invasive Alien Plants ◽  
Alien Plant ◽  
The Carpathians ◽  
Rivers And Streams ◽  
Polish Carpathians ◽  
River Valleys

The role of rivers and streams in the migration of alien plants into the Polish CarpathiansThe Carpathians are among the regions of Poland that are generally less susceptible to invasive alien plants. The factor limiting the spread of the species of this group is, above all, the mountain climate. Even species originating from other mountain regions, e.g. the HimalayanImpatiens glandulifera, have their localities only at low elevations, in the Carpathian foothills. In most cases, alien plant species migrate into the Carpathians from the lowlands. The river valleys provide the migration corridors used by alien species in the course of their progress into new territories of the upper mountain localities. The situation along some mountain rivers, where invasive alien species dominate the native vegetation, is dramatic. Their spread is facilitated not only by easy diaspore transport but also by some anthropogenic factors, such as, river engineering and the transformation of riparian habitats and progressing devastation. Currently, we can observe some invasive alien plants "in statu nascendi", developing a new, secondary range in the Carpathians (e.g.Chaerophyllum aureum) or at the foothills, along the Wisła (Vistula) and San river valleys (e.g.Eragrostis albensis). For some species, cities were the destination for the first stage of future migration, e.g.Acer negundo. In the Carpathians, where many national parks and nature reserves are located, the continuous monitoring of the spread of invasive alien plants should be one of the principal activities of botanists.

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