Csontos et al. (2012) Applied Ecology and Environmental Research

Csontos, P., Halbritter, A., Tamás, J., Szili-Kovács. T., Kalapos, T., Uzinger, N., Anton, A. (2012): Afforestation of dolomite rock grasslands with non-native Pinus nigra, and its effect on soil trace elements. Applied Ecology and Environmental Research 10: 405-415.

Abstract

The non-native  Pinus nigra has been widely planted on natural dolomite grasslands in Hungary, yet little is known on its influence on soil properties. We compared soil micro-element concentrations in rock grassland (RG) and under P. nigra plantation (PP), both grown on north facing slopes of dolomite bedrock. At PP sites, the original vegetation was RG prior to afforestation. For both vegetation types, five sampling sites were selected, and at each site soil samples were taken from three depths (0-5, 5-10 and 10-15 cm). Micro-element concentrations of corresponding soil layers in the two vegetation types were compared. Under the pine plantation, the concentration of a number of soil trace elements was altered compared to the original rock  grassland soil, and this effect increased with soil depth.  At the deepest layer, significant differences were found for 10 microelements (Al, Fe, Mn, Ba, Cd, Co, Ni, Pb, Sr, Zn), and in each case the concentration was higher in PP than in RG soil. In contrast, the concentration of Cr, Cu, Hg, Mo and Se was not different between the two habitats throughout the soil layers sampled. Values exceeding the Hungarian environmental limits of background concentrations were detected for lead and cadmium. In the RG soil, concentrations of Pb and Cd were highest in the topmost layer, while for the PP sites these elements showed concentrations higher in the 10-15 cm layer than in the 5-10 cm depth. Concentrations of some other micro-elements showed similar inversion at PP sites. The depth inversion of these, often airborne pollutant trace elements was explained as a consequence of afforestation with P. nigra and such phytostabilization effect of the pine stands is assumed to increase with stand age.

Keywords

dolomite, heavy metals, Pinus nigra, rock grassland, soil pollution

Csontos & Kalapos (2012) Grass and Forage Science

Csontos, P. & Kalapos, T. (2013): More lightweight and isodiametric seeds for C4 than for C3 grasses are associated with preference for open habitats of C4 grasses in a temperate flora. Grass and Forage Science 68: 408-417. DOI: 10.1111/gfs.12003

Abstract

Seed mass and shape of grasses were analysed in a temperate flora containing 178 and 26 species belonging to C3 and C4 photosynthetic types respectively. The weedy character and the annual or perennial status were also considered. On the basis of the seed traits studied, three groups were distinguished: C4 grasses, annual C3 grasses of weedy character and perennial non-weedy C3 grasses. The C4 group had more isodiametric (same diameter in all directions) seed shape and lower average seed mass than the C3 group. To our knowledge, this has not yet been described for temperate C4 grasses and is certainly associated with their preference for open habitats where competition for light is small. Weedy annual C3 grasses had heavier and less isodiametric seeds than C4 grasses did. These species are mostly specialized to establish in the dense cover of perennial vegetation, and this ability distinguishes them from the C4 group. Non-weedy perennial C3 species possessed less isodiametric seeds than did C4 grasses, but did not differ from weedy annual C3 grasses. As most alien C4 grasses naturalized in Hungary are annuals with small, isodiametric seeds, these traits are good candidates to be included in screening for potential future invasives in open habitats.

Keywords

C4 grasses, photosynthetic types, seed ecology, seed slenderness, thousand-seed weight, weeds

Pal et al. (2013) Plant Biosystems

Pal, R.W., Pinke, Gy., Botta-Dukát, Z., Campetella, G., Bartha, S., Kalocsai, R., Lengyel, A. (2013): Can management intensity be more important than environmental factors? A case study along an extreme elevation gradient from Central Italian cereal fields. Plant Biosystems

DOI 10.1080/11263504.2012.753485

Abstract
This paper aims to assess the importance of environmental and management factors determining the weed species composition along a strong elevation gradient. A total of 76 cereal fields (39 low input and 37 intensively managed) were sampled along an elevation gradient in central Italy. Explanatory variables were recorded for each field to elucidate the role of large-scale spatial trends, of site-specific abiotic environmental conditions and of field management characters. Redundancy analysis was used to assess the relative importance of each environmental variable in explaining the variation in species composition. Our results indicate that variation in weed species composition is strongly determined by altitude, mean annual precipitation, mean annual temperature and also by soil characteristics. However, the level of intensification proved to be the most influential variable. There was a significant difference in species richness and composition between low-input and intensively managed fields. Intensification leads to considerable species loss at both lower and higher elevations. Low-input fields had 296 species in total, while intensively managed fields had only 196.

Keywords

Intensification, intensively managed fields, low-input fields, redundancy analysis, species richness, weed vegetation

Ódor et al. (2013) Folia Geobotanica

Péter Ódor, Erzsébet Szurdoki, Zoltán Botta-Dukát, Beáta Papp (2013): Spatial Pattern and Temporal Dynamics of Bryophyte Assemblages in Saline Grassland. Folia Geobotanica, DOI 10.1007/s12224-012-9140-2


Abstract
Dynamics of bryophyte assemblages of saline grassland were studied in Hungary. A survey was carried out in two permanent plots by annual sampling of 0.25-m2 quadrats over a 9-year period. The study investigated: i) the extent of spatial and temporal dependence of the assemblages and individual species; ii) the turnover of individual species and its relationship to life-strategy types andiii) the effect of annual weather conditions on species performance. One of the plots showed succession; the frequency of some perennial species increased, while that of some short-lived species decreased; this process was independent of local weather conditions. The other plot showed a non-directional fluctuation, which was partly related to precipitation in winter and early spring. The spatial and temporal dependence of this assemblage was low; many short-lived species had a high turnover in the studied community. In stable periods, neutral dynamic processes characterize the bryophyte assemblages of the studied saline grassland and the occurrences of species were more or less independent in space and time. Short-lived species showed high fluctuations and were probably influenced by weather conditions or other factors. However, the frequency of perennial species, which were influenced by local conditions, could directionally change displacing the short-lived ones during succession. The relationships between turnover and life-strategy types were weak, both the group of colonist and shuttle species were dynamically heterogeneous. Longer observations are needed for a clearer exploration of the relationships between vegetation changes and weather conditions.


Keywords
Dynamics, Mosses, Permanent plots, Spatial dependence, Succession

Pal et al. (2013) Folia Geobotanica

Robert W. Pal, Sándor Csete, Zoltán Botta-Dukát, Gyula Pinke (2013): Composition and Diversity of Lawn Flora in Differently Managed Village Yards – A Case Study from Southwestern Hungary. Folia Geobotanica, DOI 10.1007/s12224-012-9142-0

Abstract
Traditionally managed village yards have been disappearing from the Central-European countryside. Their lawn flora is likely to provide a unique habitat for many plants that are adapted to this environment. Composition of lawn flora was investigated in differently managed village yards (i.e., regularly mown and regularly trampled yards, poultry yards, paved yards) in southwestern Hungary. The main goal of the study was to detect the impacts of these different management regimes on the composition and diversity of the vegetation. In total, 240 1-m2 plots were sampled in 60 yards ranging from 80 m2 to 5,000 m2 in size. In the redundancy analysis, eight significant variables (degree of southness, slope, age, total size of yards; mowing, trampling and grazing regime; and the number of dogs) explained 16 % of the total variation in species data. The most diverse flora across yards was detected in the paved ones, and their stands also proved to be the most compositionally distinctive. In contrast, presence of domestic animals can contribute to local species loss as well as to a decrease in within-yard-type variability. These results highlight the importance of certain anthropogenic disturbances in maintaining high plant diversity, but also underline the crucial role of small-scale land management practices in rural environments.


Keywords
Anthropogenic disturbance, Grazing, Mowing, Ruderal vegetation, Trampling

Kelemen et al. (2013) Journal of Vegetation Science

Kelemen, A., Török, P., Valkó, O., Miglécz, T., Tóthmérész, B. (2012), Mechanisms shaping plant biomass and species richness: plant strategies and litter effect in alkali and loess grasslands. Journal of Vegetation Science. doi: 10.1111/jvs.12027

Abstract
Question: Explaining the biomass–species richness relationship is key to understanding vegetation dynamics. Several possible mechanisms have been suggested, but complex analysis of plant strategies, major biomass and species richness components along a long productivity gradient is still lacking. We provide a detailed analysis of the relationship between major biomass components (total above-ground biomass, green biomass and litter), plant strategies and species richness along a long gradient of alkali and loess grasslands in a steppe landscape in Central Europe.
Location: Hortobágy, Great Hungarian Plain, East Hungary.
Methods: Above-ground biomass of characteristic alkali and loess grassland stands was sampled along a gradient of increasing productivity. In each grassland stand, a 25-m2 sample site was randomly selected. Within each site, ten above-ground biomass samples (20 × 20 cm) were collected randomly in June 2009, at the peak of biomass production. We classified all species into mixed C-S-R strategy types. To obtain correlations between various biomass and species richness data, Spearman rank correlation was used. The relationship between plant strategies and species composition were displayed with a DCA ordination.
Results: The frequently detected humped-back relationship was valid for the relation of total biomass and species richness. With increasing amount of total biomass, we detected an increasing proportion of competitors, and a decreasing proportion of stress tolerators in green biomass. A low proportion of ruderals was detected at both low and high biomass levels. Species richness was affected positively by litter at low litter scores, but there was a negative litter effect from much lower scores than detected previously (from 400 g·m−2). There was a positive relationship between green biomass production and species richness.
Conclusions: The study revealed that at the initial part of a productivity gradient, stress is likely responsible for low species richness. Our results show that litter can shape changes in species richness along the whole biomass gradient, thus the litter effect is one of the major mechanisms structuring grassland diversity.


Keywords

Alkali landscape, Competition, C-S-R strategies, Humped-back, Plant trait, Productivity, Stress, Steppe

Miglécz et al. (2013) Plant Ecology

Tamás Miglécz, Béla Tóthmérész, Orsolya Valkó, András Kelemen, Péter Török (2012) Effects of litter on seedling establishment: an indoor experiment with short-lived Brassicaceae species. Plant Ecology, DOI: 10.1007/s11258-012-0158-6

Abstract

Recruitment by seeds is essential both in vegetation dynamics and in supporting biodiversity in grasslands. The recruitment by seeds is feasible in suitable vegetation gaps from the seed rain and/or by establishment from persistent soil seed banks. Cessation of grassland management results in litter accumulation, which leads to the decline of species diversity by the decreased availability of open patches. Low amounts of litter is often beneficial, while high amounts of litter is detrimental for seed germination and seedling establishment of short-lived species. In a designed indoor experiment, we explored the effect of litter on seedling establishment by germinating six short-lived Brassicaceae species with both increasing seed mass and litter cover. We found that both seed mass and litter had significant effect on germination and establishment of the sown species. Small-seeded species were significantly negatively affected by the 300 and/or 600 g/m² litter layers. No negative litter effect was detected for species with high seed masses (Lepidium spp.). No overall significant positive litter effect was found, although for most of the species cumulative seedling numbers were not the highest at the bare soil pots. Our results suggest that the negative effects of litter are less feasible on the large-seeded short-lived species than on that of small-seeded ones.

Keywords

Biodiversity, Cruciferae, Litter, Seed size, Germination, Weed control

Schmera & Podani (2013) Ecological Indicators

Dénes Schmera, János Podani (2013): Components of beta diversity in hierarchical sampling designs: A new approach. Ecological Indicators 26: 126–136. http://dx.doi.org/10.1016/j.ecolind.2012.10.029


Abstract
Diversity partitioning has been generally used to estimate the contribution of different levels of sampling hierarchy to landscape diversity. However, beta diversity values derived by partitioning strongly depend on focus and sample size and the partitioning is inadequate to express the contribution of landscape elements to community variation. Pairwise dissimilarities are also frequently used to express community turnover, but related approaches capture only limited aspects of it, especially for hierarchical sampling designs. To avoid these shortcomings, we suggest a procedure which quantifies the role of different levels of sampling hierarchy (relative beta diversity) and the share of landscape elements in the corresponding relative beta diversity (contribution value). Our novel method uses pairwise dissimilarities and is based on partitioning a dissimilarity matrix of sampling units. It is suitable to testing various null hypotheses via permutation techniques as demonstrated by artificial and actual data. The method is a valuable tool in ecology because it complements existing approaches while providing a unique way to understand community diversity in space.


Highlights
► A method quantifying different aspects of community variation is proposed. ► We demonstrated its utility by examining artificial and actual data sets. ► Significance tests are possible via randomization models. ► It complements existing approaches to measure community variation.



Keywords
Beta diversity, Diversity partitioning, Hierarchy theory, Scale concept, Turnover

Stenger-Kovács et al. (2013) Ecological Indicators

C. Stenger-Kovács, E. Lengyel, L.O. Crossetti, V. Üveges, J. Padisák (2013): Diatom ecological guilds as indicators of temporally changing stressors and disturbances in the small Torna-stream, Hungary. Ecological Indicators 24: 138–147.http://dx.doi.org/10.1016/j.ecolind.2012.06.003


Abstract
In this research, indicator properties of the three recently described diatom ecological guilds (low profile, high profile and motile) and their responses to different stressors and disturbances were tested along a temporal gradient. Experiments were run at a standard sampling site in the Torna-stream (Hungary) between 2008 and 2010 using standardized substrata. The low profile guild was dominant during periods with low nutrient (SRP and TN) availability. In contrast, the high profile guild was dominant in resource rich (SRP and SRSi) periods. The motile ecological guild was the most sensitive to the nutrients (TN and SRSi) and some other factors (e.g. temperature, Cl−). Increasing irradiance in spring and summer favored the growth of the high and the low profile guild. Higher resistance to floods favored the adhesion type of the low profile guild enabling their summer peak in terms of relative abundance. During high flood periods, incident light availability apparently sufficed the needs of this guild. Seasonal changes of the diatom ecological guilds and guild diversity were robust and predictable. This study supported that the ecological responses of diatom ecological guilds, despite the apparent simplicity of the grouping method, is strong enough to indicate the temporally changing environmental conditions.


Keywords
Diatom ecological guilds, Stressors, Disturbances, Seasonality, Torna-stream

Lukács et al. (2013) Biological Conservation

Lukács B. A. – Sramkó G. – Molnár V. A. (2013): The plant diversity and conservation value of continental temporary pools. Biological Conservation 158: 393–400. http://dx.doi.org/10.1016/j.biocon.2012.08.024

Abstract

Temporary pools are unusual habitats because they share features of aquatic and terrestrial ecosystems. They are habitats of community interests according to the Natura 2000 network (Natura code: 3130 and 3170), and can be found in several climatic regions where they harbours various wetland habitats. Whereas Mediterranean temporary pools are well studied, only a few papers deal with their continental counterparts, probably because they are mainly found on arable fields often displaying decades-lasting dormancy. This study aims at filling this gap in our knowledge by evaluating plant species composition, habitat types and diversity of temporary pools in a region of continental climate. We analysed data from 185 phytosociological relevés (79 historical and 106 contemporary data) from different types of waterlogged arable fields, including rice paddy fields, from the Pannonian Ecoregion. We found significant differentiations of rice paddy fields from ‘other’ waterlogged arable fields according to ordination, classification and regression analyses. Diversity partitioning of species abundance data showed that these habitats have a very high alpha (species number, Simpson and Shannon) and beta diversity, which means that all the sites have high importance in habitat conservation. We found many vascular plants listed in IUCN and national red lists among the indicator and characteristic species of continental temporary pools. Our results demonstrate the conservation importance of continental temporary pools in relation to habitat and biodiversity management and conservation planning.

Keywords

Agriculture, Additive diversity partitioning, Elatine, Habitat types, Isoëto-Nanojuncetea, Lindernia procumbens, Temporary ponds, Vascular plants