To understand recent biogeographic patterns of Central European rocky steppes, we inspected phytosociological data from rocky steppes dominated by Carex humilis along an elevation gradient (from 140 to 1,350 m) and in four biogeographic regions (NW Pannonian Basin, Western Carpathians, Transdanubian Mountains and Transylvanian Basin). Due to the physiognomic uniformity, Carex humilis-dominated communities are ideal objects to reveal broad-scale vegetation patterns, which are not obvious from local and regional studies. We investigated the roles of geographic distance and environmental (climatic, topographic and geological) variables in shaping variability of the studied vegetation. We further looked for differences in structure and floristic composition regarding (1) gam-ma diversity, beta diversity and species richness; (2) life form spectrum; (3) species distribution patterns; and (4) representation of archaeophytes and habitat specialists. The large compositional variation in both lower- and higher-elevation rocky steppes was better explained by geographic distance than by the environment. Among the environmental variables, geological bedrock type and climate variables were most important. Gamma and beta diversity were higher for stands at lower elevation than those at higher elevation, with a peak in the colline belt at elevations between 300 and 500 m. Species richness did not differ with elevation or biogeographic region. The hemicryptophytes dominated in life-form spectra along the whole elevation gradient with the highest proportions at middle elevations. Low elevation plots had higher proportion of therophytes and higher elevation plots had more chamaephytes and geophytes. Large-range species prevailed at low elevations and middle range species at high elevations. Also the narrow-range species increased with elevation and among the regions were best represented in the W-Carpathians. Species with a European distribution prevailed in most plots and their proportion increased with elevation. The proportion of steppe species decreased with elevation and was highest in the Transylvanian plots. The W-Carpathian plots had the highest proportions of alpine species, which were present along the whole elevation gradient with a significantly increasing trend towards the high elevation. The archaeophytes were represented only at low and middle elevations with a decreasing trend, and had highest proportions in the Transylvanian plots. Mean niche breadth had unimodal distribution along the elevation gradient with the highest values at 600 m a.s.l. Proportions of both specialist and generalist species increased with elevation. Despite the mentioned differences, rocky steppes from various elevation belts and biogeographic regions shared a set of species with similar ecology and distribution. We conclude that a detailed analysis of biogeographic patterns based on phytosociological data can provide a valuable insight into the structure of a particular vegetation type.

Mountain ash (Sorbus aucuparia) is widespread in Europe from sea level to the timberline and reaches its most northern range in N-Norway at 71 °N. Sorbus aucupariaoccurs on acid, dry to moist and mesotrophic to oligotrophic soils. The species often grows in secondary forests together with Alnus viridis, Sambucus racemosa, Betula pendula, Frangula alnus and some Salix spp. In most climax forests mountain ash grows only in the shrub layer. In the subalpine belt, the tree is present in green alder scrub and European larch-Swiss stone pine forests. On some N-exposed mountain slopes of the S-Alps, small mountain ash forests with green alder build the upper forest limit above 1500 m. In this study, ecological and phytosociological aspects of this particular forest community along a N-S-transect from the Swiss Central Alps (Grisons) to the South Alps (Ticino/ N-Italy) were investigated. We consider site conditions, local spread, rejuvenation, tree age structure, infestation and phytosociological aspects of S. aucuparia. The occurrence of A. viridis in the N-S-transect and the role of S. aucupariain the secondary and climax forests have been investigated. While in the green alder scrub (Alnetum viridis) of the North single mountain ash trees are present, alder-mountain ash forests have been found at the S-Alpine sites with S. aucupariacovers 25–80%. Here, the Alnetum viridis is absent, and A.viridis is element of the mountain ash forests. In the montane and lower subalpine zone, S. aucupariawill often be replaced later by beech or other climax trees. Above the upper beech limit, we consider the green alder-mountain ash forests as climax forests. At the driest forest sites, grass species are pre-dominant – mainly Calamagrostis spp. and Avenella flexuosa. Based on the earlier provisional phytosociological name of S-Alpine green alder-mountain ash forests, we suggest the name Alno viridi-Sorbetum aucupariae Hari, Leisinger et Zysset 1993 – according to the first description by HARI et al. (1993). Based on our vegetation records of green alder-mountain ash forests, we propose a new sub-association Alno viridi-Sorbetum aucupariae calamagrostietosum subass. nov.

This paper provides a comprehensive survey of the results of phytocoenological research into Alnus incana forests from the alliance Alnion incanae in the Dinarides. Stands from the south-eastern Dinar-ides (Alnetum incanae = Oxali-Alnetum incanae) were analyzed and compared with those from the north-western Dinarides (Lamio orvalae-Alnetum incanae). The comparison reveals significant differ-ences in the floristic composition and in the degree of differentiation – and particularly in the presence of the species of the Illyrian floristic geoelement. Focus was placed on the area of western Croatia where a geographic variant of Helleborus dumetorum had previously been de-fined within the association Lamio orvalae-Alnetum incanae. Two of its subtypes, Salix alba and Alnus glutinosa, were determined in our research. The former subtype thrives on occasionally flooded, moist sites, where the floristic composition is dominated by hygrophytes. The latter subtype grows on elevat-ed and drier terraces and is richer in mesophilous species from the surrounding zonal forests. A floris-tic-sociological comparison of the Lamio orvalae-Alnetum incanae with the related syntaxa indicates the presence of about fourty diagnostic species which accentuate its independence and the need to assess it at the level of an independent, regional association within the alliance Alnion incanae.

During the last millennium, urbanization has considerably changed natural ecosystems and formed new artificial habitats. Habitat loss and changes in the abiotic environment are seriously affecting urban biodiversity. We investigated the vegetation composition of three urban habitat types, vacant lots, urban parks, and peri-urban grasslands, which are characterised by species typical to semi-natural grasslands and ruderal assemblages in the city of Debrecen (East-Hungary). We used five spatial replicates of each habitat type and five random plots (5 m × 5 m) in every site for our analyses. We tested the following hypotheses: (1) lower species numbers and Shannon diversity, and a higher proportion of weeds and disturbance-tolerant species are present in the city centre (i.e. urban parks) compared to more peripheral habitats (vacant lots and peri-urban grasslands), (2) the proportion of warm- and nitrogen-demanding species increases, while the proportion of moisture-demanding species decreases in habitats typical to city centres (3) we also tested the increase in cosmopolitan and alien species and the decrease in species of the natural flora in habitats typical to city centres as predicted by the urban homogenisation hypothesis. We found that species composition of urban habitat types is considerably affected by the specific disturbances and site histories associated with the certain habitats. The most urbanised habitats, the urban parks harboured the lowest number of species and the lowest Shannon diversity. The ratio of weeds and disturbance-tolerants was the highest in the city centre likely due to the high-intensity trampling and soil disturbances. Plant species of city centre were more drought-tolerant compared to periurban grasslands, which is likely due to the increased level of drainage. The ratio of nitrogendemanding species was lower in urban parks and peri-urban grasslands than in vacant lots, likely due to the high level of recent soil disturbance in this habitat type. The proportion of alien species was high both in vacant lots and peri-urban grasslands, even though their disturbance regimes differed considerably. The proportion of cosmopolitan species was significantly higher in urban parks compared to vacant lots and peri-urban grasslands. The large proportion of alien and cosmopolitan species together with the continuous human disturbance put native species at a competitive disadvantage, and accordingly the proportion of these species was lowest in the city centre. Even though the studied urban habitat patches did not contribute considerably to the preservation of rare or endangered plant species, they have an essential role in preserving the last remnants of grasslands in intensively used landscapes, and can be a good basis for urban greening projects.

Wet meadows are transitional habitats between wetlands and dry-mesophilous grasslands; thus, they are vital in sustaining biodiversity as sources, stepping stones and green corridors of species dispersal. It is especially valid for inland alkali vegetation, where high landscape-scale patchiness is typical and rapid shifts between vegetation types occur frequently. Solonetz meadows (Beckmannion eruciformis) are among the best-preserved open habitats in Europe harbouring a unique flora including several endemics. Besides their importance, studies on the vegetation of solonetz meadows are scarce even though this knowledge would be vital for their effective conservation and management. Using own records and literature data, we provide a synthesis of the alliance Beckmannion eruciformis to charac-terise its associations floristically and ecologically in five regions along the river Tisza, East Hungary. We studied three associations of the alliance: (i) Agrostio stoloniferae-Alopecuretum pratensis, (ii) Agrostio stoloniferae-Beckmannietum eruciformis and (iii) Agrostio stoloniferae-Glycerietum pedi-cellatae. We found that solonetz meadow associations were separated along a moisture gradient with Agrostio stoloniferae-Alopecuretum pratensis at the drier end and Agrostio stoloniferae-Glycerietum pedicellateae at the wet end. This gradient was also justified by the distribution of the phytosociological groups. The proportion of species of Festuco-Brometea division was the highest in Agrostio stolonifer-ae-Alopecuretum pratensis, while the proportion of Cypero-Phragmitetea species was the highest in Agrostio stoloniferae-Glycerietum pedicellateae. Species of Puccinellio-Salicornetea had the highest proportion in Agrostio stoloniferae-Beckmannietum eruciformis, indicating the high soil salinity of this association. Our results suggest that Agrostio stoloniferae-Alopecuretum pratensis association plays an important role in preserving the continental flora elements of the surrounding dry grasslands. The ecological indicator values for soil moisture and salinity suggest that in case of the studied solonetz meadow associations, humidity increases with decreasing elevation, while salinity is highest at medium elevations. Our results suggest that Agrostio stoloniferae-Beckmannietum eruciformis is a transition towards salt marsh associations, while Agrostio stoloniferae-Glycerietum pedicellatae is a transition towards freshwater marshes. Our results show that preserving solonetz meadows is an important task for nature conservation as they have a crucial role in maintaining landscape-scale species and habitat diversity and act as buffer zones around wetlands.

Artemisia annua ist ein gutes Beispiel für eine invasive Art in Mitteleuropa, die sich nach einer längeren Lag-Phase plötzlich ausbreitet. Die Art stammt aus der temperaten Zone Asiens, wo sie ihre natürlichen Vorkommen an sandigen Fluß- und Seeufern sowie Wadis der Halbwüsten und Steppen besitzt. Synanthrope Vorkommen finden sich heute in Zentralrussland, Zentral- und Südeuropa sowie in Nordamerika. Wie auch bei anderen invasiven Arten ist auch hier die erfolgreiche Ausbreitung eng mit instabilen Habitaten verbunden. So nischt sich Artemisia annua in Ruderalgesellschaften ± trockener Boden ein; ebenso werden sandige und kiesige Flußufer besiedelt. Eine Übersichtstabelle der bislang aus Mitteleuropa bekannten Aufnahmen wird präsentiert.

Im Übergangsbereich des Hügellandes zum Flachland in Südost-Niedersachsen werden 14 Waldwiesenkomplexe östlich von Braunschweig floristisch und pflanzensoziologisch untersucht. Sie weisen Restbestände des in Niedersachsen sehr seltenen und bisher erst durch wenige Vegetationsaufnahmen belegten
\nMolinietum caeruleae W. Koch 1926 auf (Tabelle 1). Dieses gliedert sich im Untersuchungsgebiet in eine Ausbildung von Thalictrum lucidum, z. T. mit Iris sibirica, der sehr extensiv genutzten Wiesenrandbereiche, eine Ausbildung von Trollius europaeus basenärmerer Standorte, eine Ausbildung von Serratula tinctoria
\nbasenreicherer Standorte und eine Typische Ausbildung. Neben den Pfeifengras-Streuewiesen werden deren Brachestadien und wichtigste Kontaktgesellschaften
\nbelegt. Auf der Basis vollständiger Sippenlisten der Gefäßpflanzen werden das floristische Potential der 14 Wiesenkomplexe verglichen und die Ursachen für dessen Heterogenität diskutiert. Aufgrund floristischer Besonderheiten werden darüberhinaus die Molinion-Bestände und deren Brachestadien eines von Äckern
\numgebenen Wiesenkomplexes westlich von Braunschweig dokumentiert.

Die Ruderal- und Saumgesellschaften des Alpensüdrandes und der vorgelagerten Ebene bei Verona (Italien) werden beschrieben und mit pflanzensoziologischen Aufnahmen belegt. Der Übergangscharakter zwischen dem mitteleuropäischen und dem submediterranen Raum spiegelt sich auch in der nitrophilen Vegetation deutlich wider: Neben zahlreichen mitteleuropäischen Assoziationen finden sich insbesondere im Bereich der Mauer- und Trittvegetation (sub)-mediterrane Pflanzengesellschaften. Für Italien nördlich des Po wird eine Übersicht der bisher von dort bekannten Ruderal- und Saumgesellschaften gegeben; sie umfaßt 42 Assoziationen und 12 Gesellschaften unbekannten Ranges.