Judita Kochjarová
Comenius University in Bratislava
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Featured researches published by Judita Kochjarová.
Biologia | 2008
Richard Hrivnák; Michal Hájek; Drahoš Blanár; Judita Kochjarová; Petra Hájková
Mire vegetation of the Muránska planina Mts and adjacent parts of neighbouring orographical units was studied in 1998–2005 using the standard Zürich-Montpellier (Braun-Blanquet) approach. We applied the defined phytosociological species groups and national formal definitions of mire associations in data processing. Within the classes Scheuchzerio-Caricetea fuscae and Oxycocco-Sphagnetea, seven associations (Caricetum davallianae, Carici flavae-Cratoneuretum filicini, Valeriano simplicifoliae-Caricetum flavae, Caricetum goodenowii, Carici echinatae-Sphagnetum, Carici rostratae-Sphagnetum and Pino mugo-Sphagnetum) were classified using formal classification criteria. Two other communities (Sphagno warnstorfii-Caricetum davallianae and Eriophoro vaginati-Sphagnetum recurvi) were not classified due to the lack of sufficient number of diagnostic species from species groups. The first DCA axis followed the mineral richness gradient. Vegetation plots were arranged from rich fens over moderately rich fens towards poor Sphagnum fens and raised bog. This fact was confirmed by a strong and significant correlation of the DCA site scores on the first axis with the measured pH and water conductivity as a surrogate of mineral richness. The second DCA axis correlated with mean Ellenberg’s indicator values for both temperature and soil nutrients. This pattern corresponds to that found in other regions of diversified Central-European landscape. We can therefore conclude that marginal geographical position and climatic specifity of the region under study did not alter gradient structure of the mire vegetation. When diversity of mire vegetation was compared to other regions in Slovakia by applying the same formal definitions to different regions, the study region was found to be conspicuously less diverse than the distribution centres of mire habitats in Slovakia (Orava and Vysoké Tatry regions), but more diverse than most of other marginal regions of mire distribution. Relatively high beta diversity of mires was probably caused by variable bedrock and local climate.
Folia Geobotanica | 2016
Marek Svitok; Richard Hrivnák; Judita Kochjarová; Helena Oťaheľová; Peter Paľove-Balang
The degradation of habitats and species loss in freshwaters is far greater than in any other ecosystem. The decline in biodiversity has a strong potential to alter the functioning of the ecosystem and the services they provide to human society. Therefore, there is an urgent need for accurate information on patterns and drivers of diversity that could be used in the management of freshwater ecosystems. We present the results of an analysis of the relationships between macrophyte species richness and environmental characteristics using an extensive dataset collected from 160 sites in two central-European bioregions. We modelled macrophyte species richness using recursive partitioning methods to assess the diversity-environmental relationships and to estimate the environmental thresholds of species richness in rivers, streams, ditches and ponds. Several hydrological and chemical variables were identified as significant predictors of macrophyte richness. Among them, pH, conductivity, turbidity and substrate composition appeared as the most important. There is also evidence that natural ponds support a greater number of plant species than man-made ponds. Based on the detected environmental thresholds, we offer a series of simple rules for maintaining higher macrophyte species richness, which is potentially useful in the conservation and management of aquatic habitats in central Europe.
Biologia | 2011
Richard Hrivnák; Judita Kochjarová; Helena Oťaheľová
The vegetation of the aquatic and marshland habitats of the Orava region (north of Slovakia) was studied in 2009, using traditional phytosociological methods. Sixteen aquatic and eighteen marsh plant communities were described within 96 phytosociological relevés by using TWINSPAN with the application of the dominance principle. Three associations, Potametum alpini, Potametum zizii and Ranunculo-Juncetum bulbosi, were found as new communities for Slovakia. Myriophylletum verticillati, Potametum nodosi, Potametum graminei and Alisma gramineum community were recorded in the northernmost localities in Slovakia. Among marsh communities, Calletum palustris is very rare, both in the Orava region and in Slovakia as a whole. According to Ellenberg’s indicator values (EIV), moisture was evaluated as the main ecological gradient. Plant communities are ordered along the first Detrended Correspodence Analysis (DCA) axis in a typical hydroseries (Potametea → Lemnetea → Phragmition communis → Phalaridion arundinaceae, Oenanthion aquaticae and Sparganio-Glycerion → Magnocaricion elatae). The second DCA axis was most correlated with EIV for nutrients. Among the five directly measured ecological characteristics (temperature, pH and conductivity of water, water depth, and substrate type), conductivity of water (0.44, P < 0.01) and substrate type (0.32, P < 0.05) were the statistically significant variables explaining the variability along the first DCA axis.
Biologia | 2013
Katarína Hegedüšová; Iveta Škodová; Monika Janišová; Judita Kochjarová
The phytosociological affiliation of Tephroseris longifolia subsp. moravica, species of European importance, was studied in relation to two closely related species of the genus Tephroseris which have overlapping distribution within the Western Carpathian Mts: T. intergrifolia and T. crispa. The main aim was to compare plant communities inhabited by the three taxa, to assess the major environmental gradients responsible for variation in their distribution and to estimate ecological indicator values for Tephroseris longifolia subsp. moravica. T. longifolia subsp. moravica was recorded in nine localities in the Slovakia and Czech Republic where it occurs in very specific site conditions of ecotone habitats. Its phytosociological affiliation is restricted to grasslands of the alliances Bromion erecti and Arrhenatherion elatioris and to the ecotone vegetation between these grasslands and beech forests. T. integrifolia occurs most frequently in the Diantho lumnitzeri-Seslerion, Bromion erecti and Quercion pubescenti-petraeae alliances. T. crispa occurs predominantly in communities of the Calthion palustris alliance and Scheuchzerio-Caricetea fuscae, Mulgedio-Aconitetea and Montio-Cardaminetea classes. The major gradient responsible for variation in species composition of communities inhabited by the studied taxa was associated with moisture and nutrient content. The vascular plant-based ecological indicator values for Tephroseris longifolia subsp. moravica calculated from phytosociological relevés with its occurrence were set for light — 6, temperature — 5, continentality — 4, moisture — 5, soil reaction — 6 and nutrients — 5. We conclude that the studied taxon has intermediate relationship to the most of the studied factors in comparison with two related species, T. crispa and T. integrifolia.
Biologia | 2006
Judita Kochjarová
Tephroseris palustris (syn. Senecio palustris) is a circumboreal species with large distribution range. The European part of the recent distribution area extends southwards to central France, Germany, Poland, and Ukraine, while in Great Britain, Czech Republic, Hungary, Slovakia, and Romania, T. palustris has been treated as extinct species. The southern boundary of its distribution in Poland does not reach the Carpathian territory. Herbarium specimens, formerly collected in Czech Republic, were found, however, all Czech localities are extinct. No herbarium specimens confirming the old literature data from Slovakia, Hungary, and Romania have been found. Some herbarium specimens coming from this area, and declared as T. palustris (S. palustris), in fact, refer to Senecio paludosus L. Contrary to previous nomenclature review (Jeffrey & Chen 1984), the name Tephroseris palustris (L.) Rchb. seems to be correct (Reichenbach Fl. Saxon.: 146, 1842).
Biologia | 2006
Iva Hodálová; Judita Kochjarová
New chromosome numbers for two species from the Senecio nemorensis group: S. dacicus (2n = 40) and S. ucranicus (2n = 40) have been ascertained. The counts for S. germanicusWallr. subsp. germanicus (2n = 40), S. hercynicus Herborg subsp. hercynicus (2n = 40), S. ovatus (P. Gaertn. et al.) Willd. subsp. ovatus (2n = 40) occurring in the Carpathians are also reported. The study confirmed only the known tetraploid chromosome number for the taxa of this group. The pollen fertility ranged from 82.09 to 92.99% in all examined species and subspecies, including their hybrids.
Biologia | 2016
Richard Hrivnák; Judita Kochjarová; Kateřina Šumberová; András Schmotzer
Abstract Lindernia dubia (L.) Pennell, a Northern-American species, was recently found in two localities in central Slovakia (near Trenč and Štiavnické Bane villages) as a new species for the flora of Slovakia. Individuals of the species grew in wetland vegetation of the class Isoëto-Nano-Juncetea in both cases. The second mentioned locality probably belongs to the altitudinal maxima of L. dubia in Europe. Although the origin of L. dubia in the Slovak localities remains unknown, we suppose that zoochory or anthropochory are the most probable modes of its introduction into the territory of Slovakia.
Preslia | 2015
Milan Chytrý; Tomáš Dražil; Michal Hájek; Veronika Kalníková; Zdenka Preislerová; Jozef Šibík; Karol Ujházy; Irena Axmanová; Dana Bernátová; Drahoš Blanár; Martin Dančák; Pavel Dřevojan; Karel Fajmon; Dobromil Galvánek; Petra Hájková; Tomáš Herben; Richard Hrivnák; Štěpán Janeček; Monika Janišová; Šárka Jiráská; J. Kliment; Judita Kochjarová; Jan Lepš; Anna Leskovjanská; Kristina Merunková; Jan Mládek; Michal Slezák; Ján Šeffer; Viera Šefferová; Iveta Škodová
Botanical Journal of the Linnean Society | 2006
Judita Kochjarová; Milan Valachovič; Petr Bureš; Patrik Mráz
Hydrobiologia | 2016
Milan Novikmec; Ladislav Hamerlík; Dušan Kočický; Richard Hrivnák; Judita Kochjarová; Helena Oťaheľová; Peter Paľove-Balang; Marek Svitok