Tuexenia : Mitteilungen der Floristisch-Soziologischen Arbeitsgemeinschaft, Band 36 (2016)
Refine
Year of publication
- 2016 (20)
Document Type
- Article (20)
Has Fulltext
- yes (20)
Is part of the Bibliography
- no (20)
Keywords
- species richness (4)
- phytosociology (3)
- succession (3)
- Koelerion glaucae (2)
- plant community (2)
- plant diversity (2)
- Alkali grassland (1)
- Allio-Stipetum (1)
- Alnion incanae (1)
- Armerion elongatae (1)
Halting the loss of grassland biodiversity and restoring degraded ecosystems are high priority tasks in the EU Biodiversity Strategy. Sowing low-diversity seed mixtures is widely used in grassland restoration because of its high predictability and fast, promising results. Generally, the sown perennial grasses establish within a few years and form a dense sward, which effectively suppresses weeds. Unfortunately, these grasslands are often species-poor because the sown grasses hamper the colonisation of target grassland forbs. Our aim was to test a novel approach to increase the diversity of species-poor grasslands. We selected eight 8-year-old grasslands restored by low-diversity seed sowing where we created 32 establishment gaps by breaking up the grass sward and sowing a high-diversity seed mixture (35 native species). Altogether, we established three grazed gaps (1m × 1m, 2m × 2m and 4m × 4m) and one fenced gap (4m × 4m) per site and monitored the presence and abundance of sown and non-sown species within a time frame of two years. We asked the following questions: (1) Which target species establish most successfully? (2) What is the effect of establishment gap size on the establishment success of target species and weeds? (3) What is the effect of management (grazed versus not managed) on the species composition of the establishment gaps? Our results showed that by creating establishment gaps and sowing diverse seed mixtures, we were able to overcome microsite and propagule limitation, successfully introducing target species into the species-poor grasslands. We found that all sown species established in the gaps, and the majority of the species maintained or even increased their first-year cover in the second year. Smaller gaps were characterised by lower cover of sown species and a quite stochastic development compared to the larger ones. Weed cover was moderate in the first year and decreased significantly in the second year, regardless of gap size. Therefore, in restoration practice, the use of larger establishment gaps is recommended. We found that the cover of sown species and weeds were similar in the grazed and unmanaged gaps during our study. However, management by extensive grazing might be crucial in the long-term because livestock can disperse target species propagules and create microsites. Our study shows that establishment gaps can serve as biodiversity hotspots. Further studies need to clarify to what extent they can improve the restoration success across the entire grassland.
Im östlichen Südtirol wurden Wiesen entlang der Gradienten Meereshöhe, Bodenfeuchtigkeit, Bewirtschaftungsintensität über saurem bzw. basischem Gestein erhoben und in 12 Vegetationstypen gegliedert. Sie wurden durch numerische Syntaxonomie bzw. den rechnerischen Vergleich mit einer Auswahl von Tabellen aus der Literatur den entsprechenden Pflanzengesellschaften zugeordnet. Aus den Beschreibungen der jeweiligen Syntaxa wurde die Bewirtschaftungsintensität abgeleitet. Dies führte zur Differenzierung von extensiven (ungedüngten), halbintensiven (schwach bis mäßig gedüngten, ohne flüssige Wirtschafts- und Mineraldünger) und intensiven (reichlich gedüngten, meist mit Gülle) Wiesentypen. Da sich die Stickstoffzahlen signifikant unterschieden, stellen die Wiesentypen zuverlässige Indikatoren für die jeweiligen Bewirtschaftungsintensitäten dar. Intensivwiesen wiesen mittlere Stickstoffzahlen über 6,0 auf und wurden dem Poo-Trisetetum poetosum trivialis zugeordnet, halbintensive Wiesen mit Stickstoffzahlen zwischen 4,0 und 5,0 gehören dem Poo-Trisetetum arrhenatheretosum, dem Trisetetum flavescentis typicum bzw. -nardetosum und dem Angelico-Cirsietum oleracei an. Extensive Wiesen hatten durchschnittliche Stickstoffzahlen unter 4,0 und gehören dem Potentillo erectae-Brachypodietum pinnati brometosum erecti und -avenuletosum praeustae, dem Sieversio-Nardetum strictae typicum und -festucetosum nigricantis, dem Carlino-Caricetum sempervirentis, dem Campanulo scheuchzeri-Festucetum noricae und der Scheuchzerio-Caricetea fuscae-Gesellschaft an. Die extensiven und halbintensiven Pflanzengesellschaften entsprechen traditionell bewirtschafteten Wiesen, die eine größere Artenvielfalt und Variation an Vegetationstypen aufweisen als der floristisch triviale Intensivwiesentyp.
Inland sand vegetation, in our case steppic sandy grassland on base-rich soils, is highly endangered in Europe and therefore in the focus of restoration ecology. While there are studies which deal with short-term restoration success, results for an extended time are rare. We were able to analyse the success of a three-step restoration measure for 10 years.
The experiment was established on an exarable field in the Upper Rhine valley, Hesse, Germany. The three-step restoration approach comprised 1) abiotic restoration by deep-sand deposition, 2) inoculation with raked/mown plant material from two different donor sites with well-developed Koelerion glaucae/Allio-Stipetum vegetation and 3) low-intensity grazing by donkeys. The vegetation of the restoration and donor sites (also serving as reference sites to assess restoration success) was sampled on six permanent plots, respectively. Data analyses included ordination, classification and target-species ratios (TSR: relation of target species to all species).
Detrended correspondence analysis revealed a continuous succession of the restoration plots towards the corresponding reference plots: open soil decreased, ruderal species declined and target species increased. While speed of succession decreased, there was still a further improvement in the tenth year. The qualitative TSR (number of target species) reached a plateau after the sixth year with values only slightly lower than at the reference sites. The quantitative TSR (cover of target species) showed a steady improvement and even excelled one reference site. Koelerion glaucae species were present with constancy 17–67% since the 3rd year, with 33–100% since the 7th year. It does not completely resemble either reference site due to a mixture of propagules of both donor sites (e.g. by wind and donkeys) and input from the surroundings. Already in the first year, three Red-list species established themselves, since the 8th year 23 Red-list/near-threatened species have been present. Some ruderal species colonised the restoration site and occurred permanently.
Additionally, we studied the establishment of the highly threatened species Bassia laniflora after inoculation for 6–12 years on three further plots adjacent to the other ones. One of these plots was located on a former sandy field without abiotic restoration; two other plots represented typical Koelerion glaucae vegetation on a newer deep-sand deposition. Bassia laniflora established itself well on all plots. We conclude that restoration of steppic sandy grassland, including highly threatened species, was not only permanently, but increasingly successful over a time span of 10 years. Management by grazing, however, will remain essential to suppress ruderalisation.
Semi-dry grasslands were once widely distributed communities, but today they represent some of the most vulnerable habitats in Central Europe. European and national legislation and non-governmental organizations have managed to protect some of the remaining fragments. However, despite their status as Natura 2000 habitats, they are often endangered due to improper management, fragmentation and edge effects from adjacent croplands. By using a sample of 44 semi-dry hay meadows in the south-eastern Alpine Foreland of Styria, we investigated how species-richness and trait composition of semi-dry grassland species respond to variation in patch size, connectivity, abiotic site factors and management regimes. We used linear regression models to identify the most important drivers for richness of typical semi-dry grassland species and thus conservation value. The number of typical semi-dry grassland species was highest in well-connected fragments, i.e. units that shared two or more borders with neighbouring species-rich grasslands. Furthermore, large semi-dry grasslands (> 8000 m²) had highest numbers of semi-dry grassland species and highest relevance for conservation; no difference was found among smaller fragment sizes. Unregular management was associated with increased presence of competitive species which replaced stress-tolerant specialists. Our study indicates that under eutrophication, small fragment size and isolation, only large semi-dry grasslands can sustain a high number of species with high conservation value. The conservation value of smaller semi-dry grassland fragments could be improved by buffer zones, adapted mowing treatments and periodical sheep grazing.
The degradation of species-rich mountain meadows has been observed in many parts of Central Europe in the last few decades. It is reflected in decreasing species numbers and changes in the proportions of plant species in the aboveground vegetation. Some species are increasing in abundance and eventually dominate the meadow vegetation. There is still a lack of studies explaining how this process is reflected in the soil seed bank. Therefore, the goal of the current study was to test whether expansive species that degrade aboveground vegetation of mountain meadows also influence, quantitatively and qualitatively, seed rain and seed bank. Soil samples were taken from 14 plots in degraded patches and another 14 plots in non-degraded patches. Nearly the same numbers of seedlings were recorded in both meadow types. In both cases, low similarities between aboveground vegetation and soil seed rain and seed bank were observed. Expansive species causing meadow degradation (Calamagrostis epigejos, Festuca rubra, Deschampsia cespitosa and Lupinus polyphyllus) reached cover values of 60–83% in the aboveground vegetation, and a share of up to 36% in the seed rain and seed bank. The mean species richness in the aboveground vegetation and the soil of degraded meadows was lower than in the non-degraded plots. However, the seed bank may buffer degradation to some extent since the degradation of aboveground vegetation was faster than impoverishment of seed bank. Consequently, seed rain and seed bank of degraded meadows still contained typical mesic meadow species in similar proportions as non-degraded meadows. This indicates that seed rain and seed bank may contribute to the restoration of degraded meadows after the removal of expansive species from the aboveground vegetation.
This paper is the continuation of a survey of the scree vegetation in alpine landscapes of western Pamir-Alai Mts in Tajikistan. In total, 105 phytosociological relevés were collected in the colline and montane belt in 2012‒2014, applying the Braun-Blanquet method. Phytocoenoses inhabiting mobile or fairly stabilised screes of different sizes of rock particles in the montane and colline zone are herein described. A hierarchical syntaxonomic synopsis of scree communities in the western Pamir Alai Mts is provided. The collected vegetation samples represent the majority of the variations among the phytocoenoses of gravel, pebble, cobble and rock block slides and screes. As a result of field survey and numerical analyses, eight associations ‒ Cousinietum corymbosae, Eremostachyetum tadschikistanicae, Cousinietum refractae, Caccinietum dubiae, Eremuretum sogdiani (with two subassociations: E. s. typicum and E. s. delphinietosum decolorati), Feruletum kuhistanicae, Zygophylletum atriplicoidis and Corydalidetum kashgaricae ‒ have been described. Because of their floristic composition, all of these communities have been assigned to a new alliance Alceion nudiflorae within the Sileno brahuicae-Scutellarietalia intermediae order and Artemisio santolinifoliae-Berberidetea sibiricae class. The main factors determining the species composition of the classified associations seem to be scree mobility, rock particle size, elevation above sea level and slope inclination. Saxicolous vegetation in Tajikistan reveal an extraordinary diversity and richness in terms of species composition and beta diversity along the main environmental gradients in this mountaionous areas. A further geobotanical survey is needed, especially in eastern Pamir and adjacent areas to fully recognize the chasmophytic plant communities of this rocky land.
Dry open rocky grassland vegetation on shallow ultramafic soils in the Central Balkans represents typical secondary grasslands, which have developed mainly in the zone of thermophilous mixed deciduous broadleaved and pine forests. Although all relevant national and regional syntaxonomic reviews classify these rocky grasslands within the distinct order Halacsyetalia sendtneri, the syntaxonomic position of the order in different systems of classification has varied in the past. Considering this as well as the fact that there have been no synoptic works on this specific vegetation type, we gathered all available data on the order Halacsyetalia sendtnerii from the serpentinites of the Western and Central Balkan Peninsula for its critical evaluation. The results obtained in our analyses allowed us to propose a new syntaxonomic concept, which is partly in accordance with previously published syntaxonomic schemes. Two alliances can be distinguished: Centaureo kosaninii-Bromion fibrosi and Potentillion visianii, for which the diagnoses, diagnostic and constant taxa are given. Furthermore, we discussed the syntaxonomic position of the order Halacsyetalia sendtneri with respect to the classes Festuco-Brometea and Koelerio-Corynephoretea, as within the analysed associations, many taxa diagnostic for the class Koelerio-Corynephoretea were registered. The thermophytic pioneer grasslands and therophyte sward communities included in the alliance Thymion jankae nomen. inval., characterised by the absence of typical species of the order Halascyetalia sendtneri and presence of taxa diagnostic for the class Koelerio-Corynephoretea, are temporarily left within the order Halacsyetalia sendtneri. Finally, we provided nomenclatural adjustments for the analysed associations when necessary, although a conclusive judgement regarding all the associations currently included within the analysed order can only be made after more detailed field surveys including data on cryptogams as well as joint analyses including all floristically and ecologically similar syntaxa (e.g. Astragalo-Potentilletalia, Festucetalia valesiacae).
Um zu überprüfen, ob sich die Artenzusammensetzung alpiner Kalk-Magerrasen (Blaugras-Horstseggenrasen, Polsterseggenrasen) im Nationalpark Berchtesgaden während der letzten drei Jahrzehnte geändert hat, wurden Vegetationsaufnahmen aus den 1980er Jahren 2013/14 zum zweiten Mal wiederholt vegetationskundlich erfasst.
Ziel der Arbeit war es, durch den Vergleich der Aufnahmenkollektive Vegetationsveränderungen während der letzten drei Jahrzehnte aufzuzeigen und diese als allogene oder autogene Prozesse zu interpretieren. Dabei wurde insbesondere der Frage nachgegangen, ob anthropogene Stickstoff-Einträge als Hauptursache für mögliche Veränderungen angesehen werden können.
Tatsächlich konnten ausgeprägte floristische Veränderungen im Vergleichszeitraum aufgezeigt werden. So hat sich seit den 1980er Jahre die mittlere Artenzahl sowohl im Polsterseggenrasen als auch im Horstseggenrasen um mehr als 10 Arten pro Aufnahmefläche erhöht. Im Polsterseggenrasen wurde ferner eine signifikante Abnahme der mittleren Kontinentalitätszahlen nachgewiesen.
Die dokumentierten floristischen Veränderungen könnten auf die globale Erwärmung und die damit verbundenen Klimaeffekte zurückzuführen sein. Auch natürlich ablaufende Sukzessionsprozesse könnten die aufgezeigten Änderungen in der Artenzusammensetzung erklären, allerdings ist die Zeitspanne von 30 Jahren zu kurz, als dass eine autogene Sukzession als der Hauptfaktor angesehen werden kann. Denkbar ist aber, dass Sukzessionsprozesse durch die globale Erwärmung heutzutage beschleunigt ablaufen. Stickstoffeinträge oder Landnutzungsänderungen spielen als Erklärungsmodell für die Vegetationsveränderungen dagegen wohl eher eine untergeordnete Rolle.
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.
The majority of studies investigating plant functional traits have used species average trait values, and assumed that average values were sufficiently representative of each species considered. Although this approach has proven valuable in community ecology studies, plant functional traits can significant-ly vary at different scales, i.e. between but also within populations. The study of species functional trait variability can facilitate increasingly accurate studies in community ecology. Nevertheless, the current extent of within-site plant trait variability has been poorly addressed in the literature. Calcareous grass-lands are ecosystems well-suited to study plant trait variation at small spatial scales. Many species are present on heterogeneous calcareous sites, with significant differences in hydric status due to variations in soil depth, soil moisture, aspect, and slope. This study assesses the extent of intra-population func-tional trait variability and tests the hypothesis that this variability can be explained by within-site envi-ronmental heterogeneity. Three functional traits (SLA-specific leaf area, LDMC-leaf dry matter con-tent, and plant vegetative height) were assessed in three populations of four calcareous grassland spe-cies totalling 950 individuals. The heterogeneity in soil depth and potential direct incident radiation was also quantified and related to plant functional trait variability. The intra-population functional trait variability was compared to the inter-population variability of collected data and global inter-population variability data obtained from the worldwide TRY functional traits database. The results showed that SLA, LDMC, and plant height are characterized by considerable intra-population variation (SLA: 72–95%, LDMC: 78–100% and vegetative height: 70–94% of trait variability). The results also indicate higher plant height and larger SLA for individuals located in plots with deeper soils or lower potential direct incident radiation, on gentle slopes or north-facing slopes. Our findings additionally support the concept that higher plant height, higher SLA, and lower LDMC are related to higher availability of soil water. Individuals on shallow soils or in more exposed areas are better equipped to cope with environ-mental stress. Our results indicate plasticity or local adaptation in individuals to environmental hetero-geneity. This study suggests that detailed analyses involving plant functional traits require measure-ments in situ from a large number of individuals, as the degree of individual response strongly depends on an individual’s location and its micro-environmental conditions. Neglecting intra-population trait variability may be critical, as intraspecific variation can be very high at the population scale, and is likely to be driven by local environmental heterogeneity.
Plant diversity change for cities and their surroundings is well documented. For rural areas such studies are difficult as literature data are mostly insufficient. We reconstructed phytodiversity change in the Feldatal community (Germany, Hesse) by comparison of historical herbarium collections (1945–1976, Hans Hupke) with a recent floristic survey (2012). The study area is a rural area typical for Central Europe, dominated by agriculture and forestry and with a stable human population. Floristic diversity decreased (683 to 497 species; 31% of the total flora), principally by disappearance of species of unimproved grassland, fields and villages. The small number of newly documented species (33 spp.; 5% of total flora) comprises mostly naturalized ornamentals and salt tolerant species along roads. Plant diversity change of the last decades in rural landscapes in Central Europe was mainly dependent on the intensification of agriculture.
In Italy most of the habitats hosting terricolous lichens are found in the Alps and along the coasts, but some lichen-rich plant communities are also present in the Po Plain. We report a study of terrico-lous lichen communities found in dry grasslands attributed to Spergulo vernalis-Corynephoretum canescentis in the western Po Plain (Northern Italy), in accordance with the Braun-Blanquet approach. Relevés (138) were carried out in several developmental stages of the Corynephorus grassland. They were sorted manually and analyzed using ANOSIM, non-parametric MANOVA and PCA. Indicator species of the groups were found by means of INDVAL and SIMPER analyses and literature. Seven lichen vegetation types were distinguished. These were attributable to 4 described associations: Stere-ocauletum condensati, Cladonietum foliaceae (in which we found 3 subassociations: typicum, cladonietosum furcatae and cladonietosum subrangiformis), Cladonietum mitis and Cladonietum rei, and to one impoverished community (Cetraria aculeata community). Ordination of floristic variables showed several overlaps between communities, underlining the depleted floristic conditions found in the study area, where several species occur in many communities and other species are very rare, and thus play a minor role in the differentiation of the lichen vegetation types. Overlaps are also referable to intermediate conditions between one community and another, reflecting dynamic relationships, with Stereocauletum condensati, Cetraria aculeata community and Cladonietum foliaceae typicum having the most distinct pioneer character and Cladonietum mitis being the most evolved. Ordination of eco-logical variables based on the indices of substrate pH, light and humidity requirements and tolerance to eutrophication showed several overlaps between the communities, found to be from acidophytic to subneutrophytic, from rather to very photophytic, from mesophytic to rather xerophytic and from anitrophytic to slightly nitrophytic. Rarity in Italy and conservation needs are discussed in detail, also in comparison with the situation of the same communities in central European Corynephorus grasslands. These grasslands and their typical lichen communities are rare in Italy and, though somewhat depleted, they are the habitat of several threatened lichen species at the southern margin of their distribution range. Therefore management plans should always consider both the cryptogamic and the vascular plant communities.
Verglichen mit Laubwaldgesellschaften sind Langzeitstudien über Waldkiefern-Bestände (Pinus sylvestris L.) in Mitteleuropa selten und die Sukzessionsdynamik von Kiefernwäldern wurden in dieser Region bisher kaum untersucht. Obwohl es sich um den am stärksten von Feuern betroffenen Waldtyp in Mitteleuropa handelt, liegen lediglich wenige Daten zu den Auswirkungen von Bränden auf die Vegetation von mitteleuropäischen Kiefernwäldern vor. Außerdem sind Kiefernwälder in besonders hohem Maße von Eutrophierung betroffen, die starke Veränderungen in der Vegetation verursachen können. In der vorliegenden Studie wurden naturnahe, waldbrandbeeinflusste Kiefernwälder (Leucobryo-Pinetum) im Nationalpark Sächsische Schweiz (Sachsen, Deutschland) untersucht. Dauerbeobachtungsflächen wurden mit bis zu vier Wiederholungen von Vegetationsaufnahmen seit 1963 untersucht. Gemäß den einzelnen Waldbrandereignissen und dem Jahr der Flächeneinrichtung wurden drei Zeitreihen analysiert. (A: 1963-2012, Feuer: 1948/1953); B: 2002-2014, Feuer: 1993; C: 2002-2014, Feuer: 2000), Hierbei wurden unerwartet geringe Veränderungen der Pflanzendiversität und des Artenspektrums der Vegetation gefunden. Nur wenige Arten wurden kurzzeitig durch Waldbrände gefördert, und lediglich einzelne Arten zeigten signifikante Veränderungen in ihren Deckungsgraden in Abhängigkeit vom Waldbrandereignis. Nitrophyten fehlten weitgehend. Offenbar liegen die lokalen Stickstoff-Depositionsraten noch deutlich unter den für einen Vegetationswandel kritischen Werten. Verglichen mit Kiefernforsten und durch traditionelle Nutzung entstandenen Kiefernwäldern stellen naturnahe Bestände des Leucobryo-Pinetum einen relativ stabilen Waldtyp dar, der nur wenig von Waldbränden beeinflusst wird und langfristig nur einer trägen Sukzession unterliegt.
Im ersten Teil wurden erstmals für den jahreszeitlichen phänologischen Wandel einer Kulturlandschaft 12 Geophänophasen beschrieben. Die Phasen 1-9 sind vor allem durch den Blühbeginn von phänologischen Artengruppen definiert. In diesem zweiten Teil werden für diese Phasen einige quantitative Merkmale von Farbspektren vorgestellt. Die Auswertung beruht auf 520 blühenden Arten der untersuchten Landschaft. Sie wurden den Farbgruppen Gelb - Weiß - Rot - Blau sowie der Gruppe der Unscheinbaren und Grünen zugeordnet. Die Zahl blühender Arten zeigt einen Anstieg bis zum Hochsommer (Phase 8: 261 blühende Arten) mit folgendem deutlichen Rückgang. Gelb und weiß blühende Arten haben in allen Phasen die höchsten Werte. Besonders hingewiesen wird auf Kurz- und Langzeitblüher. Nach der Bedeutung ihrer Blüten für Landschafts-Farbaspekte wurden alle Arten fünf neu definierten Aspektwerten (1-5) zugeordnet. Durch Addition dieser Werte für jede Geophänophase ergeben sich für die fünf Farbgruppen absolute und relative Diagramme der Landschaftsaspekte. Dominante Farben sind in allen Phasen Gelb und Weiß. Rot zeigt eine Zunahme im Sommer. Am Ende wird die Bedeutung der farbigen Landschaftsspektren für Mensch und Tier diskutiert.
Seit 11 Jahren werden von Mitgliedern der Eurasian Dry Gassland Group (EDDG) und deren Vorgängerorganisationen Grasland-Sonderteile in Tuexenia herausgegeben. Der diesjährige Sonderteil präsentiert sechs Artikel mit unterschiedlichen Fragestellungen zu Trockenrasen und verwandten Graslandtypen aus sechs europäischen Ländern: Belgien, Bosnien-Herzegowina, Deutschland, Italien, Serbien und Ungarn. Ein Artikel behandelt syntaxonomische Aspekte der Serpentin-Steppenrasen des Balkans (s. auch Umschlagfoto). Zwei Beiträge untersuchen funktionelle Eigenschaften von Pflanzenarten im Grasland, der eine (in belgischen Trockenrasen) die Variationen funktioneller Merkmale in Abhängigkeit von den Umweltbedingungen und der andere die Mengenverhältnisse von funktionellen Merkmalen entlang eines Höhengradienten in den italienischen Alpen. Ein Artikel zeigt mithilfe eines experimentellen Ansatzes, dass artenarmes ungarisches Grasland durch Diasporenzufuhr in artenreiche Wiesen überführt werden kann, während ein anderer Beitrag ökologische Theorien am Grasland in einer ungarischen Stadt überprüft. Der sechste Artikel behandelt schließlich Vegetationsveränderungen von Steppenrasen in Nordostdeutschland nach 20 Jahren.
This paper compares the floodplain forests from Romania to those described from Central and Southeastern Europe from syntaxonomical and ecological perspectives and proposes a clear and ade-quate vegetation classification system that was needed for the Romanian floodplain forests. We performed a syntaxonomical analysis and classification of 473 vegetation relevés published from all nine Romanian provinces, between the years 1968 and 2015. The plant communities, established on the basis of character and differential species, were grouped within the alliance Alnion incanae Pawłowski 1928, according to current phytosociological consensus. The floristic structure of each syntaxon is presented in a synoptic table with species constancy expressed as a percentage. Since plant communi-ties specific to intramontane river floodplains are notably different from those in the plains, we grouped the associations within two different suballiances. Within the suballiance Alnenion glutinosae-incanae Oberdorfer 1953, we included the associations Stellario nemorum-Alnetum glutionosae Lohmeyer 1957, Telekio speciosae-Alnetum incanae Coldea 1990, and Carici remotae-Fraxinetum excelsioris Koch ex Faber 1936. In the suballiance Ulmenion Oberdorfer 1953, we included the associations Fraxino pannonicae-Ulmetum glabrae Aszód 1935 corr. Soó 1963, Ulmo campestris-Fraxinetum holotrichae Borza ex Sanda 1970 and Fraxino pallisae-Quercetum pedunculiflorae Oprea 1997. In order to show the distribution of these associations within the territory of Romania, we have generated two maps displaying the provenance of the analyzed relevés. The proposed classification system will facilitate the phytosociological and ecological investigation of floodplain forests and support the activities aiming at their conservation.
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.
The intensification of agricultural practices has led to a severe decrease in grassland biodiversity. Although there is strong evidence that organic farming can reduce the negative impacts of land use, knowledge regarding the most beneficial management system for species richness on organic grasslands is still scarce. This study examines differences in the biodiversity of plants and butterflies on rotationally and continuously grazed pastures as well as on meadows cut twice per year on two large organic suckler cow farms in NE Germany. Vegetation and flower abundance, as factors likely to influence butterfly abundance and diversity, were compared and used to explain the differences. The data attained by vegetation assessments and monthly transect inspections from May to August were analyzed using descriptive statistics and nonparametric methods. The abiotic site conditions of the studied plots had more influence on plant species numbers than the management method. Dry and nutrient-poor areas (mainly poor types of Cynosurion) and undrained wet fens (Calthion) were important for phytodiversity, measured by the absolute number of species, indicator species for ecologically valuable grasslands and the Shannon Index. Meadows tended to have more indicator species than pastures, where small-scale special sites such as wet depressions were crucial for plant diversity. Butterfly diversity was very low, and 90% of the recorded butterflies were individuals of the generalist species Pieris napi. Butterfly abundance depended mainly on occurrence of specific habitat types and specific larval host plants. Supply of flowers was crucial only in certain time periods. Differences in butterfly abundance between the management systems could be explained by the site conditions of the studied grasslands. We conclude that meadows are more favorable to support ecologically valuable plant species; however, their extension is contradictory to the organic farming method of suckler cows maintained outside of stables. Rotationally grazed pastures could be a compromise that would enhance the temporal heterogeneity of flower abundance and vegetation structure. The plant diversity on pastures should be improved by less intensive grazing on special sites and plant species enrichment by means of hay transfer. For enhancing butterfly diversity we suggest to reduce land use intensity especially on poor soils. Considering the economic perspective of the farms, small parts of the agricultural area could be sufficient if connectivity to other suitable habitats is assured. Flower abundance and diversity of larval host plants could be promoted by high diversity of farming practices as well as pre-serving small uncut strips of meadows.
Orange lily Lilium bulbiferum subsp. bulbiferum occurs in the mountains of Western and Central Europe. Within almost the entire area of distribution, it is considered to be rare and endangered. The main purpose of the present study is to analyse the variability of environmental conditions of sites of the orange lily that are considered natural on its north-eastern border of occurrence. Using vegetation databases from Poland, the Czech Republic and Slovakia and our material collected during field work in the Western Carpathians and the Sudetes, we analysed the variability of species composition within communities with the occurrence of L. bulbiferum subsp. bulbiferum. The classification was performed using a modified TWINSPAN algorithm in the JUICE software. Ecological analysis was performed on the basis of Ellenberg indicator values with a Zelený-Schaffers modified permutation test. In general, the findings indicate that in the study area there are at least seven plant communities, within three separate classes, with the occurrence of the orange lily. All vegetation units distinguished here are semi-natural communities, which are maintained through extensive and traditional agricultural practices. Microclimatic conditions, which indicate a narrow ecological tolerance of the species to light availability and temperature, may have a crucial effect on the distribution of L. bulbiferum subsp. bulbiferum on the north-eastern border of its range in Europe. These factors significantly reduce the possibility of penetration of the species into forest or scrub communities. On the other hand, owing to far wider ranges of tolerance to moisture conditions and soil reaction than previously considered typical of the species, the orange lily can occur in different light-demanding communities, from acidic pastures up to calcareous thermophilous grasslands. An almost exclusive presence of L. bulbiferum subsp. bulbiferum in semi-natural habitats suggests that active management and protection are crucial to protect its full genetic variation on the European continent.
Despite the high significance of the Western Siberian grain belt for crop production in Russia, its weed communities are largely unknown. In this region spring wheat is grown on fertile Chernozem soils with large field sizes but land-use intensity per area is low compared to Central Europe. By using a randomized sampling design we studied arable weed assemblages in the northern forest-steppe zone of Tyumen region on 99 within-field sampling plots of 100 m² size. Surprisingly, with average of 9.8 ± 3.8 species 100 m-2 species richness was low when compared with low-input farming in Central Europe and did not differ between areas of different land-use intensity. Against expectations species composition was not predominantly controlled by soil characteristics and climate, most likely due to short natural gradients. Instead, management factors such as fertilization and tillage intensity seemed to be important factors. Except for two species the Tyumen weed flora consisted mainly of species that are widespread throughout the temperate zone. We found only 10 species with an origin or core area in North Asia or Eastern Europe. The species pool was generally small and with 26% the proportion of non-native species (archaeophytes) was low, when compared to Central European weed communities. Given that weed communities with higher species richness are described from neighboring Bashkiria, we conclude that arable land-use intensity in Tyumen region is high enough to reduce community species richness within arable fields estimated by a randomized sampling design. Since measured soil nutrient values did not affect species richness, herbicide use is most likely the crucial management factor. Furthermore, species-richness was vitally restricted by the small species pool. The low proportion of thermophilous arable weed species that originate from the Mediterranean or Middle-Eastern area and contribute signif-icantly to the Central European weed diversity indicate that climatic dispersal limitations may be re-sponsible for the small number of weed species in the Tyumen flora. An additional constraint was the short history of arable farming in Western Siberia, where considerable arable land use was started only by the end of the 17th century.