Judit Házi

Dr. Judit Házi

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Research Focus & Metrics

Academic Career Length

16Years (2011-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 May 2022 in Agronomy
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JHJudit Házi
Judit Házi
Karoly PenkszaKaroly Penksza
Karoly Penksza
ABAndras Barczi
Andras Barczi
SSSzilárd Szentes
Szilárd Szentes
GPGergely Pápay
Gergely Pápay
This study is focused on the vegetation of seminatural dry grasslands. These grasslands are valuable with large biodiversity; however, their long-term preservation requires regular conservation management. This report demonstrates the results of a 13-years mowing experiment, designed to suppress the spread of an unpalatable grass species, Calamagrostis epigejos. The study site was located in mid-successional grasslands, in the Western-Cserhát, near Rád, Northern Hungary. The experimental design consisted of eight permanent plots, where mowing was applied twice a year. The vegetation was sampled annually (from 2001 to 2013). The impacts of mowing were tested using repeated–measures analyses of variance (ANOVA). In 2001, Calamagrostis epigejos was the species with the highest cover in both the mown and control sites, with an average cover value of 63%. However, as a result of mowing, a significant difference was detected in the amount of litter and legumes species as well. The number of species showed an increase in both types of treatment, from 15 to 37 in the mowed plots, but also from 18 to 27 in the control plots. We concluded that mowing twice a year proved to be a useful measure for modifying botanical composition of a grassland. It was well suited for agricultural usage, in particular grazing, which can replace the expensive and time-consuming scythe. Mowing can also be a suitable management measure for controlling native invader species such as Calamagrostis epigejos, and can significantly increase the proportion of species with higher forage values.

4 March 2022 in Land
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SBSándor Bartha
Sándor Bartha
GSGábor Szabó
Gábor Szabó
SCSándor Csete
Sándor Csete
DPDragica Purger
Dragica Purger
JHJudit Házi
Judit Házi
ZZZita Zimmermann
Zita Zimmermann
Diversity responses to climatic factors in plant communities are well understood from experiments, but less known in natural conditions due to the rarity of appropriate long-term observational data. In this paper, we use long-term transect data sampled annually in three natural grasslands of different species pools, soils, landscape contexts and land use histories. Analyzing these specific belt transect data of contiguous small sampling units enabled us to explore scale dependence and spatial synchrony of diversity patterns within and among sites. The 14-year study period covered several droughts, including one extreme event between 2011 and 2012. We demonstrated that all natural grasslands responded to droughts by considerable fluctuations of diversity, but, overall, they remained stable. The plant functional group of annuals showed high resilience at all sites, while perennials were resistant to droughts. Our results were robust to changing spatial scales of observations, and we also demonstrated that within-site spatial synchrony could be used as a sensitive indicator of external climatic effects. We propose the broad application of high-resolution belt transects for powerful and adaptive vegetation monitoring in the future.

18 December 2024 in Diversity
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SBSándor Bartha
Sándor Bartha
JHJudit Házi
Judit Házi
DPDragica Purger
Dragica Purger
ZZZita Zimmermann
Zita Zimmermann
GSGábor Szabó
Gábor Szabó
SCSándor Csete
Sándor Csete
Quantifying within-community variability and understanding the related assembly rules are important in developing and assessing grassland restoration. Beta diversity has great potential, revealing mechanisms behind community-level changes in succession. Here, we introduce two simple beta diversity indices: Microhabitat Diversity is the Shannon diversity of patches formed by the locally dominant species, and Multiplet Diversity is the Shannon diversity of subordinate species richness categories detected at a fine scale. Using null models, we tested the biotic filtering effects of dominants on the distribution of subordinates. Based on long-term vegetation monitoring data, we tested the utility of these models in grassland restoration. Sites sown with seed mixture and developing spontaneously were compared and used as test data for exploring the proposed indices. Microhabitat Diversity was larger at spontaneously developing sites, and its local maxima reflected reorganization in the mosaic structure of the community. Species richness categories with zero or one subordinate species were typical in sown grassland, while small 5 cm × 5 cm microsites where 2, 3, or 4 subordinate species co-occured were more frequent in spontaneous succession. Contrary to expectation, a slight convergence of beta diversity measures was revealed after 15 years of succession between passive and active restorations. Microhabitat Diversity and Multiplet Diversity are simple indices that complement existing methods and provide new insights into grassland restoration.

29 November 2011 in Journal of Agricultural Informatics
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Journal Article
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SBSandor Bartha
Sandor Bartha
ZZZita Zimmermann
Zita Zimmermann
AHAndrás Horváth
András Horváth
SSSzilárd Szentes
Szilárd Szentes
ZSZsuzsanna Sutyinszki
Zsuzsanna Sutyinszki
Karoly PenkszaKaroly Penksza
Karoly Penksza
Monitoring designs are often suffering from the inherent non-stationarity of the monitored systems. To overcome this limition, we propose a sampling designs based on high resolution mapping and spatial analyses with double spatial scaling process. Applying for vegetation, we record the presence of plant species along 26 m or 52 m long belt transects of 520 (or 1040) units of 0.5 cm x 0.5 cm contiguous microquadrats. Beta diversity (represented as the diversity of species combinations) is estimated by subsequent computerised samplings from the baseline transect data sets. Beta diversity is scaled with changing resolutions across a range of scales from 5 cm x 5 cm to 5 cm x 500 cm. Second, it is also scaled using moving window. Local maximum of beta diversity is repeatedly calculated in 5 m extent observational windows shifted along the transect with 1 m lag, and the spatial variability of vegetation is visualized by the related beta-diversity profile. Using field example, we demonstrate that beta diversity, when applied with our methodology, is a sensitive indicator, and it can reveal more information than alpha or gamma diversity.

1 January 2023 in Land
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JHJudit Házi
Judit Házi
DPDragica Purger
Dragica Purger
Karoly PenkszaKaroly Penksza
Karoly Penksza
SBSándor Bartha
Sándor Bartha
Our study focused on the compositional changes of Pannonian semi-natural dry grasslands. The preservation of these valuable habitats requires regular management. Our mowing experiment aimed to study the suppression of the native dominant Calamagrostis epigejos L. Roth in mid-successional grasslands. Mowing was applied twice a year in eight permanent plots. The vegetation was sampled annually from 2001 to 2021. The impacts of mowing were tested using repeated–measures analysis of variance (ANOVA). After 10 years, the cover of C. epigejos in the mown plots decreased significantly, from an initial average cover of 56.6 to 5.6%. In 20 years, it declined to 1.3%. Surprisingly, in the control plots, it decreased also from 63.7 to 6.9%. Species richness was affected by mowing: significant differences between mown and control plots were detected from the eighth year of our experiment. However, species richness steadily increased in both treatment types from 15 to 36 in the mown plots and 18 to 25 in the control plots, indicating a combined effect of vegetation succession and treatment. Our results suggest that long-term in situ experiments and comprehensive botanical studies are necessary to provide a basis for multi-objective management and reliable utilization of grasslands.

13 September 2024 in Soil Systems
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TSTünde Irén Szabó-Szöllösi
Tünde Irén Szabó-Szöllösi
ÉBÉva Horváthné Baracsi
Éva Horváthné Baracsi
PCPéter Csontos
Péter Csontos
László PappLászló Papp
László Papp
SKSzilvia Kisvarga
Szilvia Kisvarga
JKJudit Rita Keleti
Judit Rita Keleti
This research is part of a Hungarian Research OTKA project that examines the vegetation of sandy grasslands along the Danube. During this study, Festuca wagneri and Festuca tomanii were identified as potentially suitable grass species for urban planting and turf establishment based on preliminary research. Our aim was to determine the germination success of seeds from aesthetically selected individuals and to identify the growing media on which they germinate most effectively. From the collected Festuca individuals, we analyzed 30 specimens of each taxon under garden conditions and selected the individuals for germination. The Festuca tomanii individuals were uniform, so we selected only 5 individuals. The Festuca wagneri individuals were categorized into three groups: leaves and inflorescence densely upright, inflorescence shoots spread out, and low ’dwarf’ form (compact and dense but short in stature). It was assumed that Festuca species seeds would germinate better in sandy soils. To test our hypothesis, seeds from ten Festuca wagneri and five Festuca tomanii individuals, selected based on aesthetic criteria, were sown in six different substrates: a sand–peat mixture, sand, coconut fiber, peat, coconut fiber–sand mixture, and native sandy soil (Calcaric Arenosol). Contrary to our expectations, the growth and germination rates of seeds sown in peat and coconut fiber substrates were higher than those in native sandy soil. These results suggest that Festuca seeds germinate better on substrates resembling dead plant debris with a peat-like structure or on the surface of live mosses rather than on bare sand. Among the examined individuals, the seeds from the spreading Festuca wagneri group exhibited the highest germination rate, making this group particularly suitable for urban environments. Additionally, one of the upright Festuca wagneri individuals showed the highest leaf average length and should also be considered for urban planting. In contrast, despite their uniform appearance, the Festuca tomanii individuals did not demonstrate similar germination trends. In fact, the seeds from two clumps did not germinate at all, indicating that further research is necessary.