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  • Author or Editor: L. Erdős x
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During the study of the urban flora of the city of Szeged (southern Hungary) in 2011, about 100 specimens of Euphorbia prostrata Aiton, a new alien for the Hungarian flora, were found in a city park. Characterisation of the locality is provided. This record, being the one and only in the Carpathian Basin so far, confirms former observations that this meridional-subtropical species is in expansion in many parts of the world, including proper habitats of the temperate regions. A key for all species of the genus Euphorbia subgenus Chamaesyce for the region is given.

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A new closed rock sward association ( Festuco rupicolae-Arrhenatheretum Erdős et Morschhauser, ass. nova.) has been found and described in the Villány Mts (SW Hungary). This community lives in northern expositions, near the ridge or the plateau. Bedrock is limestone and dolomite. In the association dominated by the grasses Festuca rupicola and Arrhenatherum elatius , an unusual mixing of species can be encountered: species of the mesophilous forests, of the karst shrub-forests and of the xerophilous grasslands and rock swards occur together in this community. Description of the new community as a distinct association is supported by the PCoA ordination and the differential species. Ecological properties of the community were characterised by using ecological indicator values. This analysis also shows the dual character of the association. We analysed the new association by computing the spectra of the social behaviour types. The extraordinarily great amount of the disturbance tolerants is probably a consequence of the former grazing pressure or some other disturbance.

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The paper revises and re-discusses the literature dealing with the phytosociology of the Spiraea rock heath communities based on relevés collected in North Hungary (Northern Hungarian Mountain Range) and South Hungary (Mecsek and Villány Mts). The comparative analyses confirmed the separation of the formerly described two associations and added one new subassociation to each. These are Waldsteinio-Spiraeetum mediae filipenduletosum and Helleboro odori-Spiraeetum scilletosum. Differences between stands along the three possible ecological gradients (southwest-northeast, north-facing vs. south-facing and vertical) were also analysed. An obvious continentality trend is identified along a southwest-northeast gradient and obvious ecological differences are detected between the south-facing and north-facing Spiraea stands. In contrast, no ecological trend is recognisable along a vertical gradient.

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Habitat boundaries in general and forest edges in particular belong to the central issues in ecology. Theories about community and environmental edge-responses are diverse, but there is a lack of sufficient supporting field evidence: no consensus exists about distinctness and diversity of edges, and the existence of edge-related species. Moreover, as most studies focus on man-made edges, natural forest edges are less understood. We studied xeric forest edges in a wooded-steppe area. Twelve forest patches were selected, and plots were set up within the edges, the forest interiors and the grasslands. Species composition, species richness and Shannon diversity were compared between the three habitat types as well as between differently oriented edges. We identified diagnostic species for all habitats. Local habitat preferences of the edge-related species were compared to their regional preferences. Environmental factors of the different habitats were assessed by using ecological indicator values. Forest edges differed both from forest interiors and grasslands, forming a narrow but distinct habitat type between them. Species composition of the edges was not simply a mixture of forest and grassland species, but there were several edge-related species, most of which are regionally regarded as typical of closed steppe grasslands. Neither shady conditions of the forests, nor dry conditions of the grasslands are tolerated by these species; this is why they are confined to edges. Species richness and Shannon-diversity were higher within edges than in either of the habitat interiors. Ecological indicator values suggested that light intensity and temperature were higher in the edges than in the forests, but were lower than in the grasslands. In contrast, soil moisture was lower in the edges than in the forests but was higher than in the grasslands. There were slight differences between differently exposed edges concerning species composition, species richness and Shannon diversity. We conclude that edges should be considered an integral part of wooded-steppes. Their high diversity may have nature conservation implications. Our study emphasizes that edge species may be confined to edges only locally, but may have a broader distributional range in other areas. These species may be referred to as local edge species. Our results also point out that the very same edge can be interactive and non-interactive at the same time, depending on the characteristics considered.

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Ecotones between plant communities have received considerable attention among ecologists in the context of fragmentation, climate change and the management of heterogeneous landscapes. However, the predictability of ecotone dynamics is low and the processes taking place within ecotones are still poorly understood. In this study we aimed to characterize the positional and structural dynamics of thirteen ecotones in an ecotone-rich steppe–wetland landscape of Hungary in relation to the inter-annual fluctuations of water regime and the gradients of elevation and of soil composition. According to our results, the ecotones between steppe and wetland communities were sharp and their positions coincided with those places in the landscape where the rate of change in elevation was the highest, confirming that microtopography is a major determinant of ecotone position. Soil boundaries were also detected, mostly downhill to the ecotones. Interestingly, the fluctuations of the water supply had no effect on the position of the ecotones but significantly influenced a structural ecotone parameter, the compositional contrast bridged by the ecotones. High water supply caused high contrast, while low supply went along with low contrast. We explain these changes by asymmetric sensitivities to edge effects. When the water supply was low, the wetland edges became similar to the steppe edges due to the decrease of wetland specialists and to the increase of steppe specialists, but steppe edges did not exhibit an opposite change in wet years, suggesting that steppe communities dominated over wetland communities. The asymmetry in the interaction between the two communities may have pushed the soil boundaries downhill to the ecotones but the currently steppe-like soil of wetland edges could also make wetland edges more sensitive to edge effects; thus, the cause-effect relationship is difficult to disentangle.

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Periodica Mathematica Hungarica
Authors: L. Beasley, J. Brenner, P. Erdős, M. Szalay and A. Williamson
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We compared two neighbouring alkaline grasslands from a nature conservation point of view. The two grasslands are situated in different countries, resulting in different land uses. This study characterises the vegetation of the area in focus using the categories of the General National Habitat Classification System (Á-NÉR) and compares the two sides based on naturalness categories, diversity ordering, social behaviour types, differential species and some supplementary information (e.g. waste dumps, landscape elements). Plant diversity is greater on the Romanian side, but this is mainly due to disturbance tolerants, weeds and ruderal competitors. Thus, we conclude that the grassland on the Romanian side is overgrazed. In addition, there are other undesirable processes on the Romanian side. In contrast, the Hungarian side is undergrazed. We suggest that adverse effects of grazing should be minimised using careful grazing techniques and traditional methods on the Romanian side, while grazing should be re-established on the Hungarian side. Intensive nature conservation efforts must be made if we are to protect the considerable conservation values of the grasslands, which should be protected legally.

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How should the somewhat vague term of restoration success be measured? This is a critical question rooted in European law, where in fact the creation of proper replacement habitats is a prerequisite for permitting projects that trigger a loss of species or habitats. Previous studies have used indices that relied on a comparison to reference sites, for example the number of a predefined pool of target species or compositional similarity. However, since restoration sites have rarely the same biotic and abiotic conditions as reference sites, plant communities in restored sites will not perfectly match the reference sites. Furthermore, such indices fail when reference sites are lacking or degraded. Hence, there is a need for an alternative approach that evaluates the conservation value of a restored site independently from reference sites. We propose that naturalness indicator values can be an option to measure restoration success. The approach of using naturalness indicator values makes use of the fact that plants are able to indicate environmental parameters, including degradation and regeneration. We compared and measured the restoration success of three well-established methods for grassland restoration (sod transplantation, hay transfer, seeding) with three commonly used indices (diversity, number of target species, similarity to reference sites). The results verified earlier studies and showed that sod transplantation led to the highest restoration success followed by hay transfer and seeding of sitespecific seed mixtures. Further, we used those well-established indices for an evaluation of novel, naturalness-based indices (unweighted and cover-weighted mean naturalness indicator values, the sum of naturalness indicator values). While calculating the means of naturalness indicator values failed to offer conclusive information on restoration success, we could show that the sum of naturalness indicator values was highly correlated with the number of target species and compositional similarity to reference sites. Thus, our case study demonstrated that naturalness indices can be an excellent option to estimate success in grassland restoration.

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