Biology subjects

Szitar, K.

Publications and source records attributed to Szitar, K..

5 recordsLinked to original sources

bioRxiv2026

Climate-driven in-situ trait variation in an annual ruderal grass across Europe

O_LIPlant functional traits link environmental conditions to plant performance and adaptation. Growing evidence shows that in-situ intraspecific trait variation can be as important as differences between species, yet large intraspecific datasets measured in situ are rare. While most studies focused on plant morphological traits, contents of elemental nutrients in the seeds received much less attention so far. C_LIO_LIWe conducted a large-scale in-situ study of the widespread ruderal grass Hordeum murinum. We sampled 2070 individuals from 207 populations from a large part of the native range in Europe and Northern Africa. In-situ, we measured seed ripening phenology and morphological traits, and analyzed the content of elemental nutrients in the seeds. C_LIO_LIWe found that Hordeum murinum grew larger, produced seeds later, and had heavier seeds in colder and wetter areas. Plants in denser vegetation were taller with heavier seeds but formed fewer spikes. Seed nutrient content generally declined with seed weight and was mainly driven by climate. Soil conditions had only minor effects on plant traits and seed nutrients. Population identity explained much of the variation, indicating a possible genetic component. C_LIO_LISynthesis: Our findings provide a comprehensive view of Hordeum murinum responding to environmental gradients across its European distribution. Climatic variables, especially temperature, are key drivers for reproductive success and seed nutrient content, while local environments, such as biotic pressures, are more critical for growth-related traits. These patterns indicate that H. murinum modulates its growth and reproductive investment along environmental gradients, balancing phenology, stress tolerance, and limited competitive capacity. C_LI

ecology↗

bioRxiv2024

Effects of goldenrod (Solidago gigantea Aiton and S. canadensis L.) invasion on the wet meadow vegetation composition of Somogyfajsz wood pasture

In recent decades, restoring abandoned wood pastures are being rediscovered as an effective way to preserve biodiversity. Their restoration include the control of invasive plant species. In our study, we compared the vegetation composition of wet meadow patches uninvaded and invaded by giant and Canadian goldenrod in a wood pasture located in Somogyfajsz, Hungary. We sampled the vegetation of the wet meadows of the pasture in 16 pairs of 1 x 1 m invaded and uninvaded quadrats in June 2020. We studied the effect of goldenrod invasion on nature conservation value in terms of species diversity, origin of species, and Social Behaviour Types, and forage quality and quantity. The study revealed that goldenrod invasion had negative effects on species richness and community-level biomass in wet meadows, leading to a significant reduction in species diversity and total cover. Goldenrod invasion also impacted the richness and cover of both native and exotic species, with a decrease in richness but not cover, highlighting the competitive ability of goldenrods and their potential to alter vegetation composition.

ecology↗

bioRxiv2023

Hungarian Grey cattle grazing outperforms mowing during wet meadow restoration following plantation forest clear-cut

Land-use change and ecological invasion are two main drivers of biodiversity loss, and the restoration of semi-natural wet grasslands is needed to tackle invasive species and re-establish grassland biodiversity on former forest plantations. This study tested the effectiveness of two widely used management techniques (grazing by traditional Hungarian Grey cattle and mowing once a year in August) as a restoration method of wet meadows in a former forest plantation invaded by goldenrod species in Central Hungary. We compared the vegetation composition of grazed, mowed, and reference areas with semi-natural wet meadow vegetation based on plant biomass, species richness and cover of species groups of species origin, life span, growth form, and social behaviour types of Borhidi determining the grazing value and the nature conservation value of the grasslands. We found that grazing by Hungarian Grey cattle resulted in a vegetation that was more similar to the reference wet meadows than mowing once a year in late summer. Grazing was superior to mowing in terms of goldenrod control, total species richness and cover, as well as the abundance of natives, perennials, herbs, and legumes. However, in the grazed area, we detected more disturbance-tolerant and annual species than in the mowed area. Despite the improved vegetation condition in the grazed area, we identified substantial disparities between the grazed and reference areas after three years of grazing. Based on our results, we advise using continuous extensive grazing to restore and maintain semi-natural wet meadows.

ecology↗

bioRxiv2020

Oak regeneration at the arid boundary of the temperate deciduous forest biome: insights from a seeding and watering experiment

Temperate deciduous forests dominated by oaks cover extensive areas in European lowlands. These ecosystems have been under intense anthropogenic use for millennia, thus their natural dynamics, and their regeneration in particular, is still not well understood. Previous studies found that pedunculate oak (Quercus robur), one of the most widespread and abundant species in European deciduous forests, regenerates in open habitats and forest edges, but not in closed forest interiors. However, these observations usually come from the core areas of the biome, and much less is known about such processes at its arid boundary, where limiting factors may be different, and climate change may first exert its effects. In a full factorial field experiment, we tested the effects of different habitats and increased growing season precipitation on the early regeneration of pedunculate oak in a forest-steppe ecosystem in Central Hungary, at the arid boundary of temperate deciduous forests. We planted acorns into three neighbouring habitats (grassland, forest edge, forest interior) and studied seedling emergence and plant performance under ambient weather and additional watering for four years. In the grassland habitat, seedling emergence was very low, and no seedlings survived by the fourth year. In contrast, seedling emergence was high and similar at forest edges and forest interiors, and was not affected by water addition. Most seedlings survived until the fourth year, with no difference between forest edge and forest interior habitats in numbers, and only minor or transient differences in size (leaf number, height). The lack of oak regeneration in the grassland contradicts previous reports on successful oak regeneration in open habitats, and may be related to a shift from light limitation to other limiting factors, such as moisture or microclimatic extremes, when moving away from the core of the deciduous forest biome towards its arid boundary. The similar number and performance of seedlings in forest edges and forest interiors may also be related to the decreasing importance of light limitation. The above-average precipitation in the year of seedling emergence (2016) might be a reason why watering had no effect on oak regeneration. Overall, our results highlight that oak regeneration and thus forest dynamics may be limited by different factors at a biome boundary compared to its core areas. Indeed, this very simple mechanism (inability of oak regeneration in grassland habitats) may contribute to the opening up of the closed forest biome, and the emergence of a biome transition zone.

ecology↗

bioRxiv2020

Beyond the forest-grassland dichotomy: the gradient-like organization of habitats in forest-steppes

Featuring a transitional zone between closed forests and treeless steppes, forest-steppes cover vast areas and have outstanding conservation importance. The components of this mosaic ecosystem can conveniently be classified into two basic types, forests and grasslands. However, this dichotomic classification may not fit reality as habitat organization can be much more complex. In this study, our aim was to find out if the main habitat types can be grouped into two distinct habitat categories (which would support the dichotomic description), or a different paradigm better fits this complex ecosystem. We selected six main habitats of sandy forest-steppes, and, using 176 releves, we compared their vegetation based on species composition (NMDS ordination, number of common species of the studied habitats), relative ecological indicator values (mean indicators for temperature, soil moisture, and light availability), and functional species groups (life-form categories, geoelement types, and phytosociological preference groups). According to the species composition, we found a well-defined gradient, with the following habitat order: large forest patches - medium forest patches - small forest patches - north-facing edges - south-facing edges - grasslands. A considerable number of species were shared among all habitats, while the number of species restricted to certain habitat types was also numerous, especially for north-facing edges. The total (i.e., pooled) number of species peaked near the middle of the gradient, in north-facing edges. The relative ecological indicator values and functional species groups showed mostly gradual changes from the large forest patches to the grasslands. Our results indicate that the widely used dichotomic categorization of forest-steppe habitats into forest and grassland patches is too simplistic, potentially resulting in a considerable loss of information. We suggest that forest-steppe vegetation better fits the gradient-based paradigm of landscape structure, which is able to reflect continuous variations.

plant biology↗