Biology subjects

Kovacsics-Vari, G.

Publications and source records attributed to Kovacsics-Vari, G..

6 recordsLinked to original sources

bioRxiv2026

The 'false transience' hypothesis: Do we need to reconsider the seed persistence classifications of soil seed bank studies?

Background and Aims Seed bank persistence data is typically indirect, inferred from the presence and distribution of seeds in the soil. However, this approach frequently underestimates seed longevity, because dormant and low-abundance seeds can remain undetected. Here, we introduce and test the 'false transience' hypothesis which proposes that a subset of species classified as having transient seeds based on soil seed bank (SSB) studies actually possess the capacity for long-term persistence. Their perceived transience stems from methodological limitations and ecological filters, rather than physiological constraints. We also aimed to assess how the seed mass and seed production of 'false transient' species compare to the full range of tested species. Methods We focused on species considered to have transient seeds based on SSB studies. We conducted a germination experiment with 103 species using dry-stored seeds aged 10-29 years. We then assessed how the seed mass and seed number of germinating species relate to the full range of tested species. Key Results From the 103 tested species, eight species (~8%) germinated. The majority of species germinating after >10 years had large seeds and low seed numbers compared to the full range of species, and all germinating species had seed numbers below the median of the tested species. Conclusions Our results provide partial support for the proposed 'false transience' hypothesis, showing that nearly 10% of supposedly transient species can persist after more than a decade of ex situ storage. Our results also suggest that 'false transients' are frequently large-seeded with low seed production, therefore being more likely to be missed in SSB studies and erroneously classified as transient. We can conclude that relying solely on field SSB data to infer seed persistence can be misleading, suggesting that the widely observed negative relationship between seed size and persistence may also require reconsideration.

ecology↗

bioRxiv2026

High-intensity sheep grazing impoverishes soil seed banks in sand grasslands

The effects of the selection of livestock type (e.g., sheep or cattle) and grazing intensity on the soil seed bank of sand grasslands of conservation interest were studied. 25 grazed grassland sites classified into four grazing intensity categories were studied. The soil seed bank was analysed by seedling emergence; germinated seedlings were classified into morpho-functional, social behaviour type (SBT) and CSR strategy groups. The following hypotheses were tested: i) Diversity and density of soil seed banks are lower in sheep-grazed sites than in cattle-grazed ones. ii) The species composition, diversity, and density of the soil seed banks are more strongly affected by grazing intensity than by the livestock type. iii) Leaf traits, SBT and CSR strategy composition are highly affected both by livestock type and grazing intensity. The main effect of livestock type only affected seed bank density, while that of grazing intensity had a significant effect on most of the variables. Most of the studied variables were affected by the interaction of grazing intensity and livestock type. Total seed bank density was lower at all grazing intensity levels in sheep-grazed sites than in cattle-grazed ones, especially close to frequently visited places. We found that sheep grazing sustained a much lower total seed bank density and lower density of species of natural and semi-natural habitats regardless to the grazing intensity. Thus, livestock type must be carefully selected and high-intensity sheep grazing should be avoided in the long-run when managing sand grasslands. HighlightsO_LIThe soil seed banks of sheep and cattle grazed sand grassland were studied C_LIO_LIEffect of grazing intensity found the most important driver of seed bank diversity and density C_LIO_LIThe total soil seed bank density was higher in cattle than sheep grazed sites C_LIO_LIBoth intensity and livestock type must be considered in the grassland management planning C_LIO_LIHigh intensity sheep grazing should be avoided in sand grassland management C_LI

ecology↗

bioRxiv2025

Unintentional seed dispersal via container-grown garden plants: Seed density and composition vary among exporter countries

The global ornamental plant trade is well-known as an important source of alien plants, but the unintentional dispersal of seeds as contaminants of this trade is rarely considered and largely understudied. We sampled the substrate of imported container-grown plants in several garden centres in Hungary to answer the following questions: (i) What species seeds are present in the substrate of imported garden plants and in what quantity? (ii) Do the substrates of plants imported from different countries contain seeds in different density and composition? (iii) Do characteristics of the host garden plants affect the number and diversity of seeds found in their substrate? We detected altogether 2,181 seeds of 80 taxa in the substrates. On average, 1 litre of substrate contained 36 seeds of five species. Most species were alien in Hungary and considered invasive in Europe. The majority of samples contained at least one seed of a species invasive in Europe. We found that the substrate of plants imported from different countries contained seeds in different number, diversity, and composition. Thus, the structure of the horticultural trade network can shape the alien flora of importing countries. Furthermore, the substrate of needle-leaved ornamental species contained more seeds than the substrate of broad-leaved ornamentals. Our findings demonstrate that the ornamental plant trade can disperse a large number of seeds of numerous species and introduce alien species into the importing countries. We conclude that this introduction pathway deserves greater attention in invasion biology and more studies of this phenomenon are urgently needed.

ecology↗

bioRxiv2025

Inconsistent relationships detected between seed size, shape, and persistence for different plant functional groups in the Pannonian flora

Background and AimsKnowledge on seed persistence is vital from both theoretical and practical considerations but directly collecting seed persistence data for many species is rather unfeasible. Therefore, there is a need to identify traits that can predict seed persistence, but studies about the effects of seed size and shape on persistence yielded results varying across regions. We studied 392 species of the Pannonian flora (Central Europe) to asses (i) how seed mass and shape affect seed persistence, (ii) whether this effect is consistent across plant functional groups, and (iii) whether seed mass and shape are correlated in different functional groups? MethodsWe collected data on the seed mass and persistence of species and we performed measurements to calculate their Seed Shape Index, which quantifies deviation from sphericity. We analysed how seed mass and Seed Shape Index affect persistence in all herbaceous species and separately in four plant functional groups. We also tested whether and how seed mass and shape are related to each other in these groups. Key ResultsAcross all species, both seed mass and Seed Shape Index negatively affected seed persistence. The same relationship was observed separately for perennials, short-lived species, and forbs, but only seed shape affected persistence in the graminoid group. Larger seeds also tended to be less spherical in graminoid species, in contrast to all studied species and to other functional groups, where we observed inverse or no relationship between seed mass and shape. ConclusionsConsistent with many studies in other floras, both seed mass and shape negatively affected seed persistence in the Pannonian flora. However, only seed shape influenced persistence in graminoid species, suggesting that different factors may be at play in forbs and graminoids. Therefore, future studies of this relationship may need to treat and analyse graminoids separately.

ecology↗

bioRxiv2023

Alkaline and loess grasslands with contrasting richness and biomass patterns are not separated on the CSR strategy spectrum.

Studying the relationship between biodiversity patterns and processes in vegetation has been at the centre of interest in vegetation ecology for several decades. By studying the biomass of loess and alkaline grasslands along a water and salinity gradient, we aimed to analyse species diversity and CSR functional type patterns. We aimed to test the following hypotheses: i) The biomass and species richness scores and the species composition are significantly different between the sampled grassland community types. ii) The sampled communities are well separated based on the CSR strategy spectrum. iii) The amount of green biomass and litter are positively correlated with competitiveness and negatively with stress tolerance. The biomass and species richness scores and the species composition of the sampled communities along the sampled gradients were significantly different; the highest species richness, evenness and Shannon diversity values were found in loess grasslands. The highest level of litter accumulation was found in alkaline meadows. The communities were well separated in the ordinations but surprisingly, calculation of coordinates for CSR strategy types have not shown clear separation of the grassland community types. Based on the results we can conclude that the current CSR classification is too robust to delineate grassland communities in alkaline landscapes which are markedly different in composition. We point out that the CSR classification is based on the magnitude of stress, and it is not able to differentiate between the various forms of stress which might be responsible for the marked compositional differences. Therefore, developing an index focusing specifically on the functional characterisation of stressed communities and able to differentiate between different forms of stress (e.g., water and/or salinity stress) would be highly beneficial for future studies.

ecology↗

bioRxiv2022

PADAPT 1.0 - the Pannonian Database of Plant Traits

We present PADAPT 1.0, the Pannonian Database of Plant Traits which relies on regional data sources and integrates existing data and new measurements on a wide range of traits and attributes of the plant species of the Pannonian Biogeographical Region and makes it freely accessible at www.padapt.eu. The current version covers the species of the region occurring in Hungary (cc. 90% of the regions flora) and consists of 126,337 records on 2745 taxa. There are 53 plant attributes in PADAPT 1.0 organised in six major groups: (i) Habitus and strategy, (ii) Reproduction, (iii) Kariology, (iv) Distribution and conservation, (v) Ecological indicator values, and (vi) Leaf traits. By including species of the eastern part of Europe not covered by other databases, PADAPT can facilitate studying the flora and vegetation of the eastern part of the continent. Data collection will continue in the future and the PADAPT team welcomes researchers interested in contributing with data. The main task before an updated version of the database is to include species of the Pannonian region not covered by the current version. In conclusion, although data coverage is far from complete, PADAPT meets the longstanding need for a regional database of the Pannonian flora.

ecology↗