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Biome interfaces are expected to exhibit chorological symmetry, i.e., decreasing trends in the number of species associated with each of the two neighbouring biomes as we progress from one into the other. Our aim was to test for such a pattern within the forest steppe biome, which is a transition zone in itself between the temperate deciduous forests and the steppe biome. Presence of chorological symmetry would provide indirect evidence for the prehuman presence of zonal steppes in the Carpathian basin. We also whished to provide an example with this analysis for drawing biogeographical conclusions based on quantitative species occurrence data, an information source hitherto neglected in Central Europe. Occurrence patterns of forest and steppe species were analysed at the Duna-Tisza köze (Danube-Tisza Interfluve) by the traditional qualitative biogeographic method and by hierarchical classification of predicted spatial pattern based on Generalized Linear Models with logistic link function. Species presences were explained by variables describing spatial orientation. In this approach, an outgroup of sand grassland species was also added to characetrise the discrimination ability of the approach. The quantitative method discriminated the out-group of sand grassland species, providing evidence of its suitability for our purpose. The results of the quantitative investigations were also in accordance with the qualitative evaluation. Surprisingly, forest and steppe species showed similar distributional patterns, i.e., no chorological symmetry was discernable. The quantitative biogeographic approach unveiled important evidence for deciding about the potential presence of zonal steppes in the Carpathian basin. Although the observed similarity of the distribution of forest and steppe species may have multiple reasons, the major cause of the lack of chorological symmetry is most probably the lack of zonal steppe South of the forest steppe biome in the Carpathian basin. Additional explanations include land use pattern and the mountain belt around the basin acting as a refugium in the ice ages.
Some pedological and micromorphological investigations were carried out on representative red clay samples selected from a large number of profiles. On the basis of conclusions drawn from the analytical results, the red clays can be divided into the following groups: - The red clays of the foothills of the Tokaj Mountains were formed on rhyolite or rhyolite tuff, and are covered by loess in some areas. They are relic soils, older than loess, formed under the warm climate of the Tertiary Period. In addition to quartz they contain feldspars, illite, montmorillonite and a small amount of kaolinite. - The red clays of Aggtelek Karst are Tertiary relic soils formed on Mesozoic limestone. The dominant clay mineral is kaolinite, but they contain a siginificant amount of smectite as well. - The red clays of the Northern periphery of the Hungarian Plain are situated on clay, silt and sand layers of different origin or between loess depositions. They were formed in the Pliocene and at the turn of the Pliocene and Pleistocene. These soils have a medium clay content, with a large quantity of montmorillonite and a small amount of kaolinite. - Red clays formed on Permian sandstones . These rocks were formed in the Permian period, and were issued from a mixture of sediments under tropical climate, tropical weathering. They are the signs of the oldest soil formation in Hungary. They can be characterized by their kaolinite, illite, montmorillonite and hematite contents. - The red clays of the Transdanubian hilly region wereformed by the weathering of thePannonian surface between the end of the Miocene Period and the lower Pleistocene. Medium clay content is characteristic of these red clays. They contain kaolinite, montmorillonite, chlorite and a small amount of hematite. Concerning micromorphological features, speckled and granostriated b-fabrics of the groundmass, mainly due to swelling and shrinking, were observed in some samples. Clay coatings are mainly interpreted as micromorphological features of illuviation. The investigated red clays are similar to tropical and sub-tropical ferrallitic soils in respect of their formation and mineral characteristics.
Phytogeographical regions have been set up traditionally on the basis of the flora. Several examples indicate that the potential natural vegetation is also suitable for this purpose although the flora- and vegetation-based boundaries do not necessarily overlap. We define a vegetation region as an area where the physical geographic features are rather uniform, and which consists of landscapes with floristically/structurally similar vegetation and/or their repetitive mosaics. In this paper, we delimited the boundaries of the Pannonian region based on the distribution of characteristic plant communities. The line runs most often on the border between Quercus cerris-Quercus petraea and Carpinus betulus/Fagus sylvatica dominated landscapes. We provided descriptions of the potential vegetation on both sides of the boundary. The region has an area of 167,012 km2. The region is either in direct contact with the neighboring regions (e.g., Western Carpathians), or is separated from them by transitional areas (towards the Eastern Alps), and character-poor areas with non-Pannonian, non-Alpine, non-Dinaric vegetation (in the southwest to the Western Balkan). Often, the boundary does not coincide with the boundary of the Pannonicum floristic province. We found that vegetation region boundaries can help reevaluate long-established floristic region boundaries. The boundary of the ’floristic Pannonian region’ also requires revision based on integrated distribution databases and statistical analyses. We argue that the method applied here is simple, repeatable and falsifiable. Our map provides an opportunity to the European Union to use a scientifically more sound biogeographical circumscription of the Pannonian region in her Natura 2000 and other programs.
In this paper, we elaborated a new concept (the Regularities-Deviations-Uniqueness; RDU framework) to analyse regional vegetation patterns and applied it to the Pannonian region of the Carpathian Basin. We introduced three criteria, namely: distributional regularity, distributional deviation, and compositional uniqueness. Regularities conform to the pattern expected based on macroclimate and relief. Deviations are singular phenomena and are defined as the conspicuous departures from the regular pattern at odds with either zonal pattern (climate rules), or the repetitive extrazonal patterns (relief and meso-climate interactions). Endemic plant communities of the Pannonian region (defined by a unique species composition) are regarded as the unique features. The main regularities recognised for the Pannonian region are: (1) the altitudinal pattern of vegetation belts, (2) the horizontal zonation of the Dunántúl, (3) the gradient of continentality along the mountain ranges, and (4) the circular zonality of the Nagyalföld. Deviations are mostly explained by local vegetation history, mesoclimate, and edaphic factors. The major deviations include (i) occurrence of mixed Pinus sylvestris forests in Őrség, (ii) cool continental forest-steppe forests on Kisalföld, and Gödöllői-dombvidék, (iii) the direct contact of Fagus and Quercus pubescens forests (Bakony, Balatonfelvidék), (iv) the Fraxinus excelsior-Tilia spp. forests on rock outcrops, and (v) the Sphagnum bogs on the Alföld. Individuality of the Pannonian region is demonstrated by the endemic zonal forest-steppe forests and intrazonal endemic communities such as the Cerasus mahaleb-Quercus pubescens forests, and the vegetation on calcareous sand, dolomite and saline soils and the like. We argue that the introduced criteria are suitable for the entitation and description of other biogeographical regions, and offer useful tool for interregional comparisons.
The objective of our study was to analyse the results of two measuring methods (sensory evaluation and electronic tongue) and to find differences in taste between grafted and non-grafted watermelon fruit. The trained sensory panel evaluated in two years three differently treated watermelon fruit. The studied fruit samples were produced on the same growing-areas in both years but with different growing technologies. The experiment used the non-grafted/self-rooted watermelon as control sample, while the other two treatments were grafting on two rootstock types: a Lagenaria and an interspecific squash hybrid rootstock. The electronic tongue measurement showed that it is the environment/growing technology that mainly determines the characteristics of the fruit quality, not grafting. The two measurement methods can complement each other in a detailed and practical way, as technology and growing area strongly influence the quality of watermelon fruit. The research also showed that it is possible to have similar watermelon fruit quality, independently from the used rootstock type.
Fruits and vegetables are increasingly consumed as a part of healthy diets. They are routinely consumed raw, without any further antimicrobial processing. The aim of our studies was to determine radiation doses improving the microbial safety of fruits without diminishing quality parameters of these produce. Effects of low dose irradiation on the microbiota, antioxidant capacity, total polyphenol contents, firmness and sensory properties of pre-cut apple, orange and banana were investigated. Dose of 2.0 kGy was able to reduce considerably the microbiological contamination of fruits, apple, orange, banana, but microorganisms surviving the irradiation are able to recover and grow during refrigerated storage. Two kGy was an acceptable radiation dose for the treatment of these products, having no significant effect on the mentioned quality parameters.
The effect of plasma glucose concentration on the cerebral uptake of [18 F]-fluorodeoxy-D-glucose (FDG) was studied in a broad concentration range in a rabbit brain model using dynamic FDG PET measure- ments. Hypoglycemic and hyperglycemic conditions were maintained by manipulating plasma glucose applying i.v. glucose or insulin load. FDG utilization (K) and cerebral glucose metabolic rate (CGMR) were evaluated in a plasma glucose concentration range between 0.5 mM and 26 mM from the kinetic constant k1, k2, k3 obtained by the Sokoloff model of FDG accumulation. A decreasing set of standard FDG uptake values found with increasing blood glucose concentration was explained by competition between the plasma glucose and the radiopharmacon FDG. A similar trend was observed for the forward kinetic constants k1, and k3 in the entire concentration range studied. The same decreasing tendency of k2 was of a smaller magnitude and was reverted at the lowest glucose concentrations where a pronounced decrease of this backward transport rate constant was detected. Our kinetic data indicate a modulation of the kinetics of carbohydrate metabolism by the blood glucose concentration and report on a special mechanism compensating for the low glucose supply under conditions of extremely low blood glucose level.
