Search Results

1 - 10 of 45 items :

  • "ecological requirements" x
Clear All

Abstract

The European species of the genus Marsilea are presented, with special regard to Four leaf water clover Marsilea quadrifolia L., the single species occurring in Central Europe. Based on field research on the Upper Rhine in Germany and the Lower Danube in Romania the ecological requirements of the species and the plant communities in which the species lives are analysed and compared with data from other European countries. Due to the decline of the species populations as a consequence of human activities, all European Marsilea species are rare, vulnerable, endangered by extinction or extinct in the wild and included in the Red data books of most European countries. Also all the European water clovers Marsilea strigosa, Marsilea batardae and Marsilea quadrifolia have been included in the Appendix I of the Bern Convention (1979) as strictly protected species and in the Annexe II of the European Flora Fauna Habitat Directive 92/43/1992. After analysis of ecological conditions, the state of conservation and the Red List categories of Marsilea quadrifolia following IUCN criteria in the countries of occurrence are presented and possible measures for conservation are discussed as well as realised reintroduction of the species in the wild

A Proposed Target State for a Floodplain Forest Ecosystem Within an Ecological Network, with Reference to the Ecological Requirements of an Umbrella Bird Species: The Common Kingfisher

The present day cultural landscape of Europe is comprised of an ecological network of corridors and core areas (biocentres). This article proposes the use of umbrella species to define the target state of an ecosystem in a floodplain biocentre of the European Ecological Network. The umbrella species used were chosen to represent typical bird species of forested floodplains. Case studies were developed in the Litovelské Pomoraví Protected Landscape Area, a Bird Area in the Czech Republic.

Analysis of Ecology of a Little Known White Oak Quercus Polycarpa Schur, Using Geobiocoenological Typology

Quercus polycarpa Schur is a little known oak species of the Sessile Oak aggregate (Quercus petraea s. lat.). Different habitats were studied using geobiocoenological typology system in order to investigate its ecology. In total, 65 experimental plots were set in forest stands with Q. polycarpa in the main storey in 12 protected areas situated in south-east of the Czech Republic. Ecological conditions, basic tree parameters and representation of Q. polycarpa within other oak species were evaluated on each plot. The mean values of height, height of life crown setting, stem and crown diameter were related to sub-categories of geobiocoenological system and compared by one-way ANOVA and Scheffé post-hoc test. It has been found out that Q. polycarpa grow in a high number in the 2nd altitudinal zone. It often occurs in a variety of habitats with different hydric and trophic conditions. As expected, the lowest values of measured parameters were found in the dry hydric range, this species reaches the highest values in the normal hydric and mesic ranges.

Abstract

Water quality and properties of the riverbed often shape the community structure of aquatic ecosystems, occasionally sustaining the expansion of non-native species. This study aims to provide preliminary data on the ecological preferences of the invasive species Orconectes limosus, its control, and the protection of the native stock is an European priority. In order to assess the species ability to colonize small river systems, relevant tributaries in the invaded Danube sector were monitored. Statistical test indicates a preference for deep and warm rivers, low water velocity and also high concentrations of calcium.

Abstract

Metasequoia glyptostroboides is considered to be a species highly resistant to harmful environmental factors. For this reason it has been introduced to the cities. The climate of Krakow differs from that in its natural range in China. The research was focused on 40-year-old trees, planted in Kraków on fertile alluvial soils with a low level of ground water, in the vicinity of the steelworks. During the period of the highest level of air pollution in the 1970s and 1980s, the radial increment of investigated trees showed an increasing trend. At the end of the 1980s, when the emissions were reduced, a decreasing trend in radial growth was recorded. Throughout the entire period of their life the investi-gated trees have shown high homogeneity of short-term growth reactions. The sensitivity chronology of the trees was characterized by a high representativeness and a strong high-frequency signal. This may indicate that the investigated trees have shown a large sensitivity to climatic factors.

The positive effect on the radial growth of Metasequoia had a cold September in the previous year, and also a cold January, April and May in the year of ring formation. Positive impact on the growth of trees had also the high precipitation occurring in April and August, as well as high air humidity in the spring of the year of ring formation. In the period 1974–2011 fifteen signature years were found. The analysis of the climatic conditions in these years confirms the results of the statistical analyses.

Abstract

Nowadays, concerns related to mankind’s increasing and destructive impact on the environment have influenced and changed the paradigms of product development; this in turn has brought about the appearance of environmental considerations in the creation and design of new products. Numerous industrial sectors have changed their processes of product development and production to meet the ecological requirements. Issues such as the scarcity of natural resources, increasing consumption and increasing pollution also present a number of problems. This article presents a process of comparing new alternatives with a specific methodology of decision-making. It is primarily focused on the use of rare natural materials and resources that are extracted and processed.

Abstract

With its diversity of water body types, the Danube Delta offers large possibilities for studies of aquatic macrophytes, their ecological requirements, ecological amplitude and communities. Sensitive to changes in water quality and physical parameters due to human intervention in the natural ecological network, aquatic macrophytes are used as quality indicators. Using the example of the system of channels and lakes of the Gorgova-Isac-Uzlina complex and some examples from the neighboring area, the aquatic macrophytes and their communities are presented and discussed in relation to the characteristics of the habitats and the changes of the environment in the course of decades, since human intervention in the delta.

Abstract

The aim of the paper is to present materials to the taxonomic revision of the African orchid genus Bilabrella Lindl., based on herbarium materials, specimens conserved in FAA as well as literature. It was compiled using classical taxonomic methods. The research involved determining differences between Bilabrella and other genera of Habenariinae in Africa. Its morphological structure was analysed and key features for the generic taxonomy defined. An infrageneric classification is proposed. A full description of each species and distribution data are provided. The ecological requirements and phenology of all species have been assembled and systematized.

Abstract

Geranio phaei-Urticetum dioicae, a poorly known association of nitrophilous outskirts communities was characterized based on 16 phytosociological relevés. Its ecological requirements and distribution in Pomerania and Poland are presented. A new subassociations of the Geranio phaei-Urticetum dioicae allietosum ursini have been distinguished on the basis of differing species composition. Edaphic and phytocenotic conditions of the population were specified. Association is found in mineral soil of acid reaction abundant with nitrogen and phosphorus, and as to its quantity it belongs to less numerous ones at Pomerania.

Abstract

Alluvial Cnidion-type meadows (Habitat type 6440 of the Habitats Directive), mostly characteristic for the lower courses of large rivers in continental climate conditions of Europe are presented from the Lower Danube upstream the municipality of Giurgiu (river-km 510-524). The ecological requirements of the characteristic species, as well as their sensitivity to human-induced changes that derive from regular flooding, drainage, intensification of use and/or abandonment, are highlighted; these changes frequently lead to a decrease of biodiversity of the Cnidion-type meadows or to their total loss The studied meadows are compared with similar alluvial meadows from other sites of the lower Danube River basin. Finally, the strong interlocking of Cnidion type meadows with those of the Agropyro-Rumicion, Molinion and Deschampsion caespitosae alliances are discussed.