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In this paper we aim to present data on current state of steppe-like grasslands dominated by feather grasses (Stipa spp.) in the Transylvanian Lowland (Romania), and to investigate whether management type affects species composition, biodiversity, or the occurrence of rare and endangered vascular plant species in these grasslands. Twelve grassland stands, originating from nine areas and belonging to two associations, Stipetum lessingianae and Stipetum pulcherrimae from the alliance Stipion lessingianae (Festucetalia valesiacae, Festuco-Brometea), were investigated by phytosociological sampling. Our data set contains 60 relevés originating from differently managed grasslands: grazed and abandoned stands as well as former grasslands afforested with Pinus nigra. Transylvanian stands of the Stipion lessingianae occur on steep, south-facing slopes. The species composition has an accentuated sub-continental character, including several steppe elements of Siberian and Pontic origin, many of them reaching the western edge of their distribution in this region. By comparing the species composition of the two associations, we identified 12 differential species for the Stipetum lessingianae and 19 for the Stipetum pulcherrimae, but these associations also contained many species in common, which underlines their close syntaxonomic relatedness. Grazing vs. abandonment had only a slight influence on species composition and vegetation structure, while afforestation with pines resulted in strong transformations: decreased cover of the herb layer, increased cover of litter, decreased representation of diagnostic (i.e. typical) species of the two associations but increased frequency of woody, ruderal, and mesophytic grassland species. As the Stipion lessingianae belongs to the priority habitats of the Habitats Directive, these alterations call for grassland restoration measures. Our study revealed a lack of high-quality data on the vegetation of steppe-like dry grasslands in southeast Europe, where they have their largest and best-developed stands on the continent. Thus, we emphasize the need for compiling such data and for developing a consistent supranational vegetation classification of Festucetalia valesiacae communities in this region.
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 present a report on the second annual symposium of the Dry Grassland Working Group, which took place 26.-28.08.05 in Münster and was entitled ‘Observation scales in dry grasslands’ The Dry Grassland Working Group is a discussion forum for all who are dealing with dry grasslands in central Europe. It organises annual symposia on various topics and aims to prepare the volumes on dry grasslands and closely related vegetation classes within the the ‘Synopsis of the plant communities of Germany’ The Synopsis will be based on a TURBOVEG database. As its structure and reference lists are now almost fixed, we will probably be able to start with data input at the beginning of 2006.
Ziel der Arbeit ist es, die nitrophytischen Saum- und Waldverlichtungsgesellschaften grundwasserferner Standorte in Nordostniedersachsen standörtlich, strukturell und floristisch zu charakterisieren, sie diesbezüglich untereinander und mit den in Teil I behandelten Säumen nährstoffarmer Standorte zu vergleichen und sie schließlich in eine überregional stimmige syntaxonomische Gliederung einzureihen. In Nordostniedersachsen konnten wir auf der Basis von 200 eigenen Vegetationsaufnahmen 16 Assoziationen (oder ranggleiche Einheiten) unterscheiden. Für das temperate Europa haben wir diese mit Aufnahmen und Stetigkeitslisten aus 63 weiteren Literaturquellen aus 16 Ländern zu einer synoptischen Tabelle aller ausdauernden Ruderal- und nitrophytischen Saumgesellschaften grundwasserferner Standorte zusammengestellt, die insgesamt auf 10.347 Einzelaufnahmen beruht.
Sowohl die nordostniedersächsischen als auch die europaweiten Daten sprechen dafür, alle diese Gesellschaften, und damit auch Teile der bisherigen Klassen Epilobietea angustifolii und Galio- Urticetea, in den Artemisietea vulgaris zusammenzufassen. Die nitrophytischen Säume gehören darin zu zwei der vier Unterklassen: Die azidophytischen „Schlagfluren“ (Senecioni sylvatici-Epilobienea angustifolii subcl. nov.) umfassen nach derzeitigem Kenntnisstand nur die Ordnung Galeopsio-Senecionetalia sylvatici mit dem einzigen Verband Epilobion angustifolii (2 Assoziationen in Nordostniedersachsen). Die übrigen nitrophytischen Säume gehören zu zwei Ordnungen innerhalb der Unterklasse Lamio albi-Urticenea dioicae. Die Circaeo-Stachyetalia umfassen das Atropion bellae-donnae (basiphytische „Schlagfluren“, 2 Assoziationen) und das Impatienti noli-tangere-Stachyion sylvaticae (staufeuchte Innensäume, 3 Assoziationen, darunter das Scutellario galericulatae-Circaeetum lutetianae ass. nov.), während die Galio-Alliarietalia aus Geo-Alliarion (frische Innensäume, 5 Assoziationen, darunter das Bromo sterilis-Chelidonietum majoris ass. nov.) und Aegopodion podagrariae (Außensäume, 4 Assoziationen) bestehen. Wir unterziehen alle im Untersuchungsgebiet vertretenen Syntaxa einer nomenklatorischen Revision, mit umfassender Auflistung von Synonymen, Typennachweis bzw. erforderlichenfalls Typisierung für alle gültigen Namen und Begründung vorgesehener Anträge an die Nomenklaturkommission.
In einer vergleichenden Betrachtung (meist auf Verbandsniveau) arbeiten wir abschließend Gemeinsamkeiten und Unterschiede aller nordostniedersächsischen Saumgesellschaften hinsichtlich Standortbedingungen, Vegetationsstruktur und Phytodiversität heraus. Die Säume weisen, verglichen mit anderen Gesellschaften der Region, durchschnittlich eine höhere Artendichte auf. Dabei sind die Syntaxa basenreicher Standorte im Allgemeinen artenreicher als jene saurer Standorte. Unter anderem aufgrund ihres großes Längen-Breiten-Verhältnisses beherbergen Säume entlang von Gehölzen in ihrer Gesamtheit auf sehr kleiner Fläche einen erheblichen Teil des regionalen Arteninventars an Gefäßpflanzen und besitzen so einen bedeutenden Naturschutzwert.
Der diesjährige 8. Trockenrasen-Sonderteil von Tuexenia beginnt mit einen Bericht über die aktuellen Aktivitäten der European Dry Grassland Group (EDGG). Zunächst geben wir einen Überblick über die Entwicklung der Mitgliederzahl und den aktuellen Vorstand, der im Mai 2013 gewählt wurde. Dann berichten wir vom letzten European Dry Grassland Meeting in Prespa (Griechenland, 2012) und informieren über künftige Tagungen und Forschungsexpeditionen der EDGG. Schließlich war und ist die EDGG sehr aktiv darin, Special Features in internationalen Fachzeitschriften herauszugeben. Im zweiten Teil des Vorwortes geben wir eine Einführung zu den sechs Artikeln des diesjährigen Trockenrasen-Sonderteils: Zwei davon beschäftigen sich Biodiversitätsanalyen von Grasland-Ökotonen in einer Flusslandschaft in Lettland bzw. von brachgefallenen Alvar-Trockenrasen in Estland. Der dritte Artikel behandelt die Ökologie und Vergesellschaftung einer Grassippe (Avenula adsurgens subsp. adsurgens) im brachgefallenen, montanen Grasland der Karpaten (Slowakei). Die letzten drei Artikel schließlich sind der Beschreibung und Syntaxonomie von Trockenrasen gewidmet: Zwei davon bilden den Start einer neuen Serie über die pannonischen Trockenrasen Österreichs (Allgemeine Einführung und Trockenrasen des Wienerwalds), während der letzte die Ergebnisse der dritten EDGG-Forschungsexpedition im Jahr 2011 nach Bulgarien präsentiert. Schließlich geben wir einen Ausblick über künftige Pläne für das Special Feature.
We first report from the 5th Dry Grassland Meeting held from 28th to 30st of August 2008 in Kiel, Germany. Then we take stock of the achievements of the German Arbeitsgruppe Trockenrasen and the international Working Group on Dry Grasslands in the Nordic and Baltic Region towards establishment of vegetation databases of dry grasslands in these study regions. At the conference, the European Dry Grassland Group (EDGG) was founded as an international platform of dry grassland researchers and conservationists. As networking tools it provides a homepage on the internet, publishes a quarterly electronical bulletin, and will organise the future European Dry Grassland Meetings. In the last part of this contribution, we give a short introduction to the five articles of this Special Feature. Four of them make a major contribution to supra-national classification of Koelerio-Corynephoretea and Festuco- Brometea communities, respectively, by providing syntaxonomic overviews based on comprehensive data from eastern European countries for which only few data have been available until now. The other major focus of the Feature papers is on degradation and restoration of various types of dry grasslands.
In many regions of Central Europe, semi-natural grasslands have experienced severe vegetation changes, e.g. compositional change and overall species loss, because of land use changes, atmospheric nitrogen input and also climate change. Here we analysed the vegetation change in a dry grassland complex (Gabower Hänge) in the Biosphere Reserve Schorfheide-Chorin (NE Brandenburg, Germany), one of the driest regions of the country. We resampled four 10 m² plots of each of four typical alliances (Festucion valesiacae, Koelerion glaucae, Armerion elongatae, Arrhenatherion elatioris) about 20 years after their original sampling with a recovery accuracy of approx. 10 m. The cover of vascular plants, bryophytes and lichens was recorded in both samplings. The overall compositional change was analysed with a detrended correpondence analysis (DCA). To interpret this change, we calculated unweighted mean Ellenberg indicator values for old and new plots. Furthermore we tested differences in constancy of individual species between old and new plots as well as differences in species richness, cover of herb and cryptogam layer, ecological indicator values and unweighted proportion of species groups (vascular plants, bryophytes, lichens), floristic status (native or not), life forms, CSR-strategy types and Red List species. The results of the ordination indicated no significant vegetation change, but revealed tendencies towards more nutrient-rich conditions. Ellenberg indicator values for nutrients and soil reaction were significantly correlated with the axes of the ordination. There were 28 species exclu-sively found in the new plots and 45 species of the old plots missing. While no species decreased signif-icantly, there were seven species that increased significantly. Mean species richness was significantly increased in the new plots. There were no significant differences in mean Ellenberg indicator values. Proportions of vascular plants, neophytes, hemicryptophytes and CS-strategists decreased. We conclude that overall vegetation changes are small, indicating that the dry grassland complex at the Gabower Hänge is still in a good state and of high conservation value. This relative stability over time compared to the situation in many other dry grasslands throughout temperate Europe is likely attributable to low nitrogen deposition and the dryness of the local climate. However, the detected tendency towards more nutrient-rich conditions should be taken into account in future management.
Elevational gradients in high mountain ranges are particularly suitable to study and understand patterns and drivers of plant community diversity and composition, yet there are only few studies that explicitly addressed this topic for the European Alps. Here we analysed an elevational gradient in grasslands of the Gran Paradiso National Park (NW Italy) from c. 1,700 to 3,100 m a.s.l. We recorded vascular plant species composition in 13 100-m² plots, each with two series of nested subplots from 0.0001 to 10 m², as well as a set of environmental parameters (topography, soil). Beta-diversity was assessed via the z-values of power-law species-area relationships, both across all plot sizes and from one plot size to the next bigger one. Diversity-environment relationships were assessed with multi-model inference based on Akaike information criterion (AIC), while scale dependence in z-values across plot sizes was analysed with an ANOVA. Life forms and three major functional traits (specific leaf area = SLA, canopy height, seed mass) were derived from trait databases to calculate fractions of life forms and community-weighted means for the metric traits. Species richness on 100 m² ranged from 17 to 65, with a mean of 43.5. The z-values were within a typical range known for European grasslands (mean: 0.227), with non-significant scale dependence. The importance of environmental factors for richness changed across grain sizes, with inclination (positive effect), mean soil depth and soil skeleton content (both: negative effect) being most influential at grain sizes of 0.0001–1 m². By contrast, soil pH was most important (with a unimodal relationship) for 10 and 100 m². After account-ing for the other environmental factors, elevation showed a moderate unimodal relationship only for the two largest grain sizes. By contrast, functional composition showed strong and mostly significant rela-tionships with elevation: hemicryptophytes and geophytes became rarer and chamaephytes more fre-quent, while community-weighted means of SLA, canopy height and seed mass decreased. Our findings highlight the scale dependence of biodiversity patterns, thus pointing to the need of multi-scale sampling to reach comprehensive understanding. Further, we could provide one of the first documentations of biodiversity and functional composition along an elevational gradient in the Alps, some in agreement with expectations, others not. This suggests that more extensive studies with a similar design in this and other regions of the Alps could be a valuable contribution to the understanding of how environmental factors drive components of biodiversity as well a functional community assembly.
We studied the dry grasslands of shallow, skeletal soils (Sedo-Scleranthenea, Koelerio-Corynephoretea) in northern Europe, based on a combination of new relevés from southern Oland (Sweden, n = 182) and Saaremaa (Estonia, n = 73) as well as a comprehensive evaluation of literature data, of which 65 suitable relevés were directly included in our analyses. Apart from a few vague indications of acidophytic Sedo-Scleranthenea communities (order Sedo-Scleranthetalia), all data refer to basiphytic communities (Alysso-Sedetalia); our analyses are thus focussed on the latter. The Nordic Alysso-Sedetalia communities proved to be quite different from their temperate counterparts and thus are included in a separate alliance, Tortello tortuosae-Sedion albi, which forms the northern counterpart to the central European Alysso-Sedion. Within the northern alliance, we distinguish two suballiances. The more widespread central suballiance Tortello tortuosae-Sedenion albi inhabits different types of base-rich substrata in both natural and anthropogenic sites, and is comprised of the Cladonio symphicarpiae-Sedetum albi and the Ditricho flexicaulis-Sedetum acris. The second suballiance Tortello rigentis-Helianthemenion oelandici is restricted to the alvar sites (= treeless limestone plateaus) in Oland, Gotland, Västergötland and Estonia. It is characterised by several endemic taxa and a large number of cryptogams typical of alvar. It is comprised of four associations, Crepido pumilae-Allietum alvarensis, Fulgensio bracteatae-Poetum alpinae, Helianthemo oelandici-Galietum oelandici and Gypsophilo fastigiatae-Globularietum vulgaris. All six Nordic associations are described in detail with respect to their floristic composition, ecology, distribution and lower-ranked units, and each is represented by a vegetation table. The floristic differences within the Nordic communities are worked out in a synoptic table. Whereas several vegetation scientists have pointed out that vegetation types occurring at the limits of their distribution ranges in northern Europe are generally difficult to classify, our application of the Braun-Blanquet approach, which is based on a priori separated structural types and the general application of the central syntaxon concept, has enabled us to characterise and adequately define all Nordic communities. The Tortello-Sedion associations are two to three times as species-rich as those of the Alysso-Sedion and are among the most diverse small-scale plant communities ever described. We discuss the reasons for this exceptionally high plant diversity and the peculiar species mixture in the Tortello-Sedion and compare the relationship between Alysso-Sedion and Tortello-Sedion to the situation of other Nordic syntaxa of predominantly temperate vegetation types. Our results further underline the uniqueness of Baltic alvars and their paramount importance for conservation at the European level.
Trockenrasen (v. a. Klassen Koelerio-Corynephoretea und Festuco-Brometea) gehören zu den auf kleinen Flächen artenreichsten Pflanzengesellschaften überhaupt und stellen ideale Modellsysteme für die Analyse von Phytodiversitätsmustern und deren Ursachen dar. Ich gebe einen Überblick der in verschiedenen Trockenrasentypen Europas auftretenden Durchschnitts- und Maximalwerte der Artenzahlen von Gefäßpflanzen, Moosen und Flechten auf unterschiedlichen Flächengrößen zwischen 1 mm2 und 100 m2. Gesellschaften der Festuco-Brometea sind generell artenreicher als jene der Koelerio-Corynephoretea. Die bislang höchsten publizierten Artendichten stammen jedoch aus dem Gypsophilo fastigiatae-Globularietum vulgaris, einer basiphilen Felsgrusflur der schwedischen Insel Öland (Ordnung Alysso alyssoidis-Sedetalia, Koelerio-Corynephoretea). Sie betragen auf 4 m2 durchschnittlich 53,6 und maximal 80 Arten. Die geringsten Artendichten unter den Trockenrasen weisen das Caricetum arenariae und das Corniculario-Corynephoretum (beide Ordnung Corynephoretalia canescentis, Koelerio-Corynephoretea) mit durchschnittlich weniger als 10 Arten auf 4 m2 auf. Die Artenzahl-Areal-Beziehung von Trockenrasen lässt sich über den ganzen betrachteten Dimensionsbereich exzellent durch eine Potenzfunktion S = c • A z beschreiben. Dabei unterscheiden sich die z-Werte verschiedener Trockenrasentypen nur geringfügig und betragen im Mittel 0,21. Das führt dazu, dass die Reihung verschiedener Trockenrasengesellschaften hinsichtlich ihrer Artenzahl auf unterschiedlichen Skalenebenen nahezu unverändert bleibt, und eröffnet die Möglichkeit, Artenzahlen auf andere Flächengrößen zu extrapolieren.
Es folgt eine Erörterung der wichtigsten Faktoren, welche die Verteilung der Phytodiversität in Trockenrasen beeinflussen. Die größte Bedeutung hat hier die Bodenreaktion. Im Allgemeinen wurden stark steigende Artendichten mit zunehmendem pH-Wert, teilweise auch ein erneuter leichter Abfall oberhalb des Neutralpunktes gefunden. Eine Abnahme der Artendichte mit zunehmender Höhenlage im Gebirge konnte zumindest in zwei Fällen auch für Probeflächen gleicher Größe nachgewiesen werden. Abschließend diskutiere ich die Gründe für den überdurchschnittlichen Artenreichtum von Trockenrasen, weise auf Forschungsdefizite hin und unterbreite Empfehlungen für die Konzeption und Durchführung künftiger Studien der Biodiversitätsforschung wie auch der pflanzensoziologischen Datenerhebung allgemein. Als vordringliche Qualitätskriterien erachte ich die Arbeit mit standardisierten Probeflächengrößen und die sorgfältige Berücksichtigung von Moosen und Flechten.
