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Many current approaches to the formal definition of vegetation units have the disadvantage of leaving a large amount of relevés unclassified. In this paper I propose a new method for the unambiguous assignment of relevés, which is based on the summarised cover value of diagnostic species. In the first step, a relevé is assigned to the class with the highest cover score. For this purpose, the character and differential species of the class as well as the character species of all subordinated syntaxa are considered diagnostic. Once the class has been determined, the assignment proceeds successively to the lower ranks. This method, which may be called “summarised percentage cover approach”, uses solely the diagnostic species of syntaxa for the assignment of relevés to vegetation units, making additional formal definitions unnecessary. As a test data set, I used 487 relevés of fringe vegetation and grasslands of nutrient-poor sites sampled in the Vienna Woods (Wienerwald), Austria. All relevés were provisorily classified at alliances level, mostly following the assignment of the original authors. TWINSPAN and DCA were applied to evaluate this preliminary classification. Diagnostic species for both the alliance and the class level were identified using the total cover value ratio as fidelity measure. The subjective classification was largely confirmed by the numerical methods. On basis of the summarised cover of Trifolio-Geranietea and Festuco-Brometea species, between 64% (Geranion sanguinei) and 99% (Seslerio-Festucion pallentis) of the relevés were reassigned to the same class as in the original classification. The fact that a considerable amount of relevés originally classified as Geranion sanguinei was reassigned to grasslands reflects the problems in delimiting fringe communities rather than a poor performance of the assignment method. The “summarised percentage cover approach” allows not only for the unequivocal assignment of relevés to an existing classification system, but may also help to improve classifications by clarifying the delimitation of higher syntaxa.
As second part of a series focusing on the Pannonian grasslands of Austria, we present a detailed classification of the grasslands of the Vienna Woods (Wienerwald). This region, although geographically belonging to the Alps, has strong floristic affinities to the Pannonian Basin. The eastern slopes of the Vienna Woods are a hotspot of xero-thermophytic vegetation and exhibit the highest vascular plant species richness in Austria at a scale of 3' x 5'. We used the TWINSPAN classification of a large data set reported in the first part of this series as starting point. Relevés that were considered as misclassified at the level of alliances were manually re-arranged. From this table, an excerpt containing only the relevés of the Vienna Woods was used for the present study (1055 plots). We re-classified the relevés preliminary labelled as Arrhenatherion with another TWINSPAN run. Clusters for which no ecological difference could be detected were merged. The final delimitation of associations and subassociations was achieved by adjusting their diagnostic species so as to get units that were most informative in terms of environmental conditions. All re-arrangements were based on the summarised cover of diagnostic species within individual relevés. As a result, the grasslands of the Vienna Woods are classified within 22 associations (plus two subassociations) belonging to ten alliances and four classes. Within the Seslerio-Festucion pallentis, a new association Scorzonero austriacae-Caricetum humilis is described. The semi-dry grasslands of the study area previously classified as Onobrychido-Brometum are de-scribed as new association Filipendulo vulgaris-Brometum erecti and assigned to the Cirsio-Brachypodion. The Anthoxantho-Agrostietum tenuis is reported for Austria for the first time, and its syntaxonomy is discussed within a broader geographical context.
Syntaxonomic revision of the Pannonian grasslands of Austria : 1. Introduction and general overview
(2013)
The Pannonian part of Austria is a diverse landscape situated in the transition zone between the Alps, the Bohemian Massif and the Carpathian Basin. Although the grasslands of this region have been investigated in many botanical and vegetation studies, their phytosociological classification has remained confusing. With this paper, we start a series aiming at a developement of a revised, consistent system of the Austrian Pannonian grasslands. Here we present a general overview focusing on the higher syntaxonomic units. We define grasslands as all types of meadows, pastures, fens and primary steppes. We selected all available relevés of Pannonian grasslands from the Austrian Vegetation Database. Additional unpub-lished data were included from the Danube National Park and the Biosphere Reserve Vienna Woods. To account for the comparatively low number of relevés from the northern part of the Pannonian region of Austria (Weinviertel), we included also data from southern Moravia (Czech Republic). This set of 3384 relevés was classified using TWINSPAN. Relevés that were considered as misclassified at the alliance level according to the summarised cover of diagnostic species were manually re-arranged, and the data-set specific fidelity of species to alliances was calculated using the phi coefficient. The first TWINSPAN division largely corresponded to the traditional border between the classes Festuco-Brometea and Molinio-Arrhenatheretea. The conventional alliance concepts were generally well supported. As an exception, the distinction between Diantho-Seslerion and Bromo-Festucion pallentis was not reproduced at all. Therefore, we unite all rocky grasslands on calcareous soils in a single alliance Seslerio-Festucion pallentis. We also advocate the inclusion of all basiphilous semi-dry grasslands of the study area within a single alliance Cirsio-Brachypodion. Each of the corresponding TWINSPAN clusters showed a clear prevalence of Cirsio-Brachypodion species. Moreover, two separate alliances of semi-dry grasslands would have almost no regional character species.
We first report from the 7th European Dry Grassland Meeting held 27 May to 1 June 2010 in Smolenice, Slovakia, devoted to the main topic "Succession, restoration and management of dry grasslands". Apart from the scientific programme and the excursions, we also summarise the outcomes of the General Assembly of the EDGG and present the Smolenice Grassland Declaration. Then we take stock of the dynamic development of the European Dry Grassland Group (EDGG), report on its activities during the past year, and announce its future plans. Finally, we give a short introduction to the four articles of this Special Feature, which deal with biodiversity patterns, vegetation classification, and dynamics of dry grassland habitats. One presents a detailed phytosociological study of the xeric and mesic grasslands of the Slovak part of the Biele Karpaty Mts. The second provides a new numeric approach to the assignment of relevés to syntaxa and exemplifies this in a case study for the delimitation of the classes Festuco-Brometea against Trifolio-Geranietea sanguinei in Austria. The third article investigates the septennial impact of mouflon grazing and weather on dry grassland plant communities in dry grassland patches of the Czech Republic. The fourth article deals with long-term abandonment of grasslands in Central Slovakia and shows the importance of vegetation structure, ecological stability, and low-disturbance regime for specific ant assemblages.
We performed a survey of grassland communities in the Ukrainian Carpathians with the aim of: (1) syntaxonomically classifying the meso- and subxerophilous grassland vegetation; (2) analysing the main gradients in their species composition; (3) estimating the effect of selected environmental factors on grassland species composition; (4) assessing the species richness of vascular plants and bryophytes in relation to the measured environmental variables. We collected 46 phytosociological relevés during the growing seasons of 2010 and 2011. Species composition and species richness were studied at two spatial scales (1 m² and 16 m²) in relation to soil parameters (soil depth, pH (KCl), content of P, K, Mg, N and C), management regime (mowing, grazing, ploughing in the past and burning), and other factors (altitude, litter cover, open soil, inclination, solar radiation and animal excrement). Seven grassland types were distinguished belonging to 3 classes and 4 alliances, namely the Nardetea strictae including the Violion caninae (mesic pastures at altitudes of 400–600 m mostly on moderate slopes) and the Nardo strictae-Agrostion tenuis (grasslands on moderate slopes at altitudes of 700–900 m usually managed by mowing and grazing the aftermath); the Molinio-Arrhenatheretea, including the Arrhenatherion elatioris (submontane grasslands originated mostly on former fields after their abandonment in the past) and the Cynosurion cristati (intensive pastures); and the Festuco-Brometea including the Cirsio-Brachypodion pinnati (abandoned grasslands dominated by Brachypodium pinnatum and Inula salicina). Detrended correspondence analysis indicated that the major compositional turnover was related to altitude and soil reaction. A canonical correspondence analysis confirmed that altitude had the strongest effect on species composition in the analysed dataset, followed by management treatments (former ploughing, grazing intensity). For vascular plant species richness, regression tree analysis identified grazing intensity as the most important predictor at the 1 m² scale. At the 16 m² scale, soil humus content was evaluated as the most important predictor of vascular plant species richness, followed by litter cover and grazing intensity. The number of bryophytes was not determined by the studied environmental factors at either of the two spatial scales. Although the number of analysed relevés in this study was limited, our results significantly contribute to the understanding of submontane grasslands in the Ukrainian Carpathians.
Die Steppenrasen des NSG „Badraer Lehde–Großer Eller“ werden hier erstmalig beschrieben und analysiert. 156 Originalaufnahmen wurden über eine Clusteranalyse in sieben Assoziationen und zwei ranglose Gesellschaften innerhalb der Verbände Alysso-Sedion, Seslerio-Festucion pallentis, Festucion valesiacae, Xerobromion und Cirsio-Brachypodion gegliedert. Die Auswertung alter Luftbilder zeigt, dass die beiden ranglosen Gesellschaften junge Steppenrasen auf ehemaligen Ackerflächen darstellen, während die Assoziationen überwiegend alte Steppenrasen repräsentieren. Der erste floristische Gradient nach einer NMDS in der Vegetation wird durch Variablen erklärt, die die Temperatur und die Wasserversorgung der Standorte anzeigen. Der zweite floristische Gradient kann durch das Alter der Flächen erklärt werden. Alte Steppenrasen enthalten signifikant mehr gefährdete Pflanzenarten als junge Steppenrasen, während sich der Gesamtartenreichtum zwischen jungen und alten Beständen nicht signifikant unterscheidet. Ein CSR-Strategietypenspektrum zeigt in einer Gesellschaft auf ehemaligen Ackerflächen eine höhere Bedeutung der C-Strategie, sonst aber kaum Unterschiede zwischen den Syntaxa. Die beiden Xerobromion-Assoziationen sind besonders artenreich und enthalten überdurchschnittlich viele gefährdete Pflanzenarten. Eine Gesellschaft auf ehemaligen Ackerflächen enthält durchschnittlich viele und die andere fast keine gefährdeten Arten. Der Artenreichtum der Gefäßpflanzen ist am stärksten positiv mit der Bodengründigkeit, der Deckung der Krautschicht und dem Ellenberg-Zeigerwert für Bodenreaktion und negativ mit dem Zeigerwert für Temperatur korreliert. Unsere Studie zeigt die hohe Bedeutung des NSG für den Trockenrasenschutz. Diese beruht vor allem auf der allgemein hohen Artenvielfalt und Diversität an Gesellschaften sowie auf der sehr hohen Zahl gefährdeter Arten.
The Cocktail method was applied to a small data set derived in a regional survey on riparian forest in the Polish part of the Sudetes. Formalised classification revealed the occurrence of seven associations. Considering the ecological character, three distinct groups emerged among them: i) alluvial forests (Salicetum albae, Alnetum incanae), ii) forests of small and medium mountain streams with only a narrow riparian zone (Salicetum fragilis, Stellario nemorum-Alnetum glutinosae and Fraxino-Alnetum) and iii) forests developed on waterlogged soils of spring-fed areas (Carici remotae-Fraxinetum and Piceo-Alnetum). The associations Salicetum fragilis and Piceo-Alnetum are reported for the first time from Poland. Analysis of GIS-derived environmental variables showed that average altitude, stream power index (SPI) and river order were significantly different among the associations, while there were no differences among average values of slope, solar radiation and topographic wetness index (TWI). Significant differences in species richness among the associations were also identified. Application of the Cocktail method in regional studies was also discussed.
The Transylvanian Plateau in Romania is well known to host large areas of a variety of dry grassland types, still traditionally managed by low-intensity mowing or grazing. While this natural heritage is now under threat from changes in agricultural practices, the diversity of Transylvanian dry grasslands is still little understood. There is a lack of both field data sampled with standardised methods and a syntaxonomic treatment with modern statistical methods and supra-regional perspective. Therefore, the European Dry Grassland Group (EDGG) carried out its first international Research Expedition in Transylvania 2009 to study syntaxonomy, vegetation-environment relationships, and biodiversity patterns of these communities. In various locations across Transylvania, we sampled 10-m² vegetation plots (n = 82) and nested-plot series from 0.0001 m² to 100 m² (n = 20), including all vascular plant, bryophyte, and lichen species, as well as structural and soil data. The vegetation classification was carried out with modified TWINSPAN, followed by determination of diagnostic species with phi values and a small-scale re-assignment of relevés with the aim of crispness maximisation. Both TWINSPAN and ordination revealed three major groups of syntaxa, which were matched to three orders from the class of basiphilous dry grasslands, Festuco-Brometea, represented by one alliance each: rocky dry grasslands (Stipo pulcherrimae-Festucetalia pallentis: Seslerion rigidae); xeric grasslands on deep soils (Festucetalia valesiacae: Stipion lessingianae) and meso-xeric grasslands on deep soils (Brachypodietalia pinnati: Cirsio-Brachypodion pinnati). We accepted nine association-level units plus two that potentially merit association status but were only represented by one relevé each. Most of the units could be identified with one or several previously described associations. To support nomenclatural stability, we provide a nomenclatural revision and designate nomenclatural types where previously there were none. Further, we used DCA ordination and analysis of variance to determine the main environmental drivers of floristic differentiation and to determine ecological and structural differences between the vegetation types. The strongest differentiation occurred along the aridity gradient with the dense, particularly diverse stands on more or less level sites on the one hand (Brachypodietalia pinnati) and the more open, less diverse stands on steep south-facing slopes on the other end of the gradient (Stipo pulcherrimae- Festucetalia pallentis, Festucetalia valesiacae). The two xeric orders were then separated along the second DCA axis, with the Stipo pulcherrimae-Festucetalia pallentis inhabiting the stone-rich sites at higher altitudes while the Festucetalia valesiacae occur on soft, deep substrata at lower altitudes. The analysed dry grassland communities have extraordinarily high -diversity at all spatial scales for all plants and for vascular plants, but are relatively poor in bryophytes and lichens. Some formerly mown stands of the Festuco sulcatae-Brachypodietum pinnati (Brachypodietalia pinnati) are even richer in vascular plant species than any other recorded vegetation type worldwide on the spatial scales of 0.1 m² (43) and 10 m² (98); the respective relevés are documented here for the first time. Also, the b-diversity of the grasslands was unexpectedly high, with a mean z-value of 0.275. Despite its limited extent, the methodological thoroughness of this study allows us to shed new light on the syntaxonomy of dry grasslands in Romania and to raise the awareness that Transylvania still hosts High Nature Value grasslands that are bio - diversity hotspots at a global scale but at the same time are highly endangered through changes in agricultural practices.
In our contribution, we report on the 6th European Dry Grassland Meeting held from 31 August to 1 September 2009 in Halle (Saale), Germany. The meeting was attended by 40 participants, who gave 15 oral and 17 poster presentations. The rapid positive development of the European Dry Grassland Group (EDGG), the organiser of this conference, is mentioned: the inclusion of the EDGG in the International Association for Vegetation Science (IAVS) as a working group, the establishment of two new subgroups focussing on Mediterranean and South-East European dry grasslands, respectively, and the organisation of the first EDGG research expedition in 2010 belong to the most important events. In the last part of our contribution, we give a short introduction to the six articles of this Special Feature. Two of them deal with phytosociological classification of semi-natural grassland communities, one with vegetation- environment relationships. Two papers are concerned with conservational topics, one focussing on the population structure of endangered Pulsatilla patens, the other dealing with conservation of xeric grasslands in Transylvania. The last paper examines temporal changes in calcareous grasslands with regard to species diversity.
Dry grasslands of NW Bulgarian mountains : first insights into diversity, ecology and syntaxonomy
(2013)
We present the data of the 3rd research expedition of the European Dry Grasslands Group (EDGG), which was conducted in 2011 in two contrasting areas in NW Bulgarian mountains. The aim was to collect plot data for comparing Bulgarian dry grasslands with those of other parts of Europe in terms of syntaxonomy and biodiversity. We sampled 15 nested-plot series (0.0001–100 m²) and 68 normal plots (10 m²) covering the full variety of dry grassland types occurring in the Vratsa area (Balkan Mts.) and the Koprivshtitsa area (Sredna Gora Mt.). In the plots all vascular plants, terricolous non-vascular plants and a set of soil and other environmental parameters were determined. By applying modified TWIN-SPAN, we distinguished 10 floristically well characterised vegetation types at the association level. After comparison with the regional and European literature, we propose to place them within three classes and five orders: Festuco-Brometea with the orders Stipo pulcherrimae-Festucetalia pallentis (xerophilous dry grasslands of base-rich rocks; alliance Saturejion montanae), Brachypodietalia pinnati (meso-xeric, basiphilous grasslands; alliances Cirsio-Brachypodion pinnati and Chyrsopogono grylli-Danthonion calycinae), Calluno-Ulicetea with the order Nardetalia stricae (lowland to montane Nar-dus swards; alliance Violion caninae), and Koelerio-Corynephoretea with the orders Sedo-Scleranthetalia (open communities of skeleton-rich, acidic soils; alliance unclear) and Trifolio arvensis-Festucetalia ovinae (closed, meso-xeric, acidophilous grasslands; alliance Armerio rumelicae-Potentillion). The Violion caninae with the association Festuco rubrae-Genistelletum sagittalis is reported from Bulgaria for the first time, while the two occurring Koelerio-Corynephoretea communities are described as new associations (Cetrario aculeatae-Plantaginetum radicatae, Plantagini radicatae-Agrostietum capillaris). According to DCA the main floristic gradient was largely determined by soil conditions, differentiating the Festuco-Brometea communities on soils with high pH and high humus content from the Koelerio-Corynephoretea communities on acidic, humus-poor soils, while the Calluno-Ulicetea stands are the connecting link. At 10 m2 Festuco-Brometea and Calluno-Ulicetea stands were richer in species across all investigated taxa and in vascular plants than Koelerio-Corynephoretea stands; the latter were richest in lichen species, while bryophyte richness did not differ significantly among syntaxa. Among the Bulgarian classes, the species-area relationships tended to be steepest in the Festuco-Brometea (i.e. highest beta diversity), but both alpha and beta diversity clearly fell behind the Festuco-Brometea communities in the Transylvanian Plateau, Romania, located less than 500 km north of the study region. Overall, our study contributes to a more adequate placement of the Bulgarian dry grasslands in the European syntaxonomic system and provides valuable data for large-scale analyses of biodiversity patterns.