Grasländer des gemäßigten Europas in einer sich verändernden Welt : Vorwort zum 16. EDGG-Sonderteil in Tuexenia

Mitglieder der Eurasian Dry Grassland Group (EDGG) und deren Vorgängerorganisationen geben seit 16 Jahren Grasland-Sonderausgaben (Special Features) in Tuexeniaheraus. Das diesjährige Special Feature mit dem Titel Grasländer des gemäßigten Europas in einer sich verändernden Welt umfasst sieben Artikel, die verschiedene Aspekte der Graslandforschung beleuchten und dabei unterschiedliche Organismengruppen einbeziehen: LLUMIQUINGA et al. untersuchten Langzeiteffekte von Einsaat, Mahd und Kohlenstoffzusatz (Reduktion der Nährstoffverfügbarkeit durch Verschiebung des C/N-Verhältnis) auf den Renaturierungserfolg von pannonischem Sandgrasland auf ehemaligen Äckern. BÓDIS et al. verglichen die kurzfristigen Effekte verschiedener Pflegemaßnahmen (Mahd mit/ohne Abfuhr des Schnittguts sowie Brennen) auf den ökologischen Zustand aufgegebener Pfeifengraswiesen in Westun-garn. BALOGH et al. analysierten Verzehrraten und Ernährungspräferenzen von Rindern in artenreichen Steppenwiesen der ungarischen Tiefebene, um eine nachhaltige Grasland- und Viehwirtschaft zu er-möglichen. HEER et al. untersuchten Dichteeffekte der zwei Hemiparasiten Melampyrum arvense und M. nemorosum auf die Pflanzenartenvielfalt im Grasland der Insel Saaremaa (Estland). KUMMLI et al. führten 25 Jahre nach der Ersterfassung eine Wiedererhebung der Artenzusammensetzung und Diversi-tät und der Vegetation von urbanen Grasländern in Zürich durch. CHARMILLOT et al. (2021) untersuch-ten die Vegetationsveränderungen von Kalkhalbtrockenrasen des Schweizer Juras in den vergangenen 40 Jahren mittels Wiedererhebungen von bekannten Untersuchungsflächen. ROLEČEKet al. (2021) korrigierten den 2019 in Tuexenia veröffentlichten Höchstwert von 106 Arten (ROLEČEKet al. 2019) in einer siebenbürgischen Steppenwiese (Rumänien), der aufgrund einer fehlerhaften Flächenabgren-zung in einer 10,9 m2-Fläche und nicht wie angegeben in einer 10 m2 großen Fläche ermittelt wurde,und meldeten gleichzeitig neue Höchstwerte für den Artenreichtum an Gefäßpflanzen, die jemals in 10 m2-Flächen ermittelt wurden (115 und 110 Arten in zwei benachbarten Flächen)

Organic vs. Conventional Grassland Management: Do 15N and 13C Isotopic Signatures of Hay and Soil Samples Differ?

Distinguishing organic and conventional products is a major issue of food security and authenticity. Previous studies successfully used stable isotopes to separate organic and conventional products, but up to now, this approach was not tested for organic grassland hay and soil. Moreover, isotopic abundances could be a powerful tool to elucidate differences in ecosystem functioning and driving mechanisms of element cycling in organic and conventional management systems. Here, we studied the δ15N and δ13C isotopic composition of soil and hay samples of 21 organic and 34 conventional grasslands in two German regions. We also used Δδ15N (δ15N plant - δ15N soil) to characterize nitrogen dynamics. In order to detect temporal trends, isotopic abundances in organic grasslands were related to the time since certification. Furthermore, discriminant analysis was used to test whether the respective management type can be deduced from observed isotopic abundances. Isotopic analyses revealed no significant differences in δ13C in hay and δ15N in both soil and hay between management types, but showed that δ13C abundances were significantly lower in soil of organic compared to conventional grasslands. Δδ15N values implied that management types did not substantially differ in nitrogen cycling. Only δ13C in soil and hay showed significant negative relationships with the time since certification. Thus, our result suggest that organic grasslands suffered less from drought stress compared to conventional grasslands most likely due to a benefit of higher plant species richness, as previously shown by manipulative biodiversity experiments. Finally, it was possible to correctly classify about two third of the samples according to their management using isotopic abundances in soil and hay. However, as more than half of the organic samples were incorrectly classified, we infer that more research is needed to improve this approach before it can be efficiently used in practice

Acceptance of near-natural greenspace management relates to ecological and socio-cultural assigned values among European urbanites

Grasslands are widespread elements of urban greenspace providing recreational, psychological and aesthetic benefits to city residents. Two urban grassland types of contrasting management dominate urban greenspaces: frequently mown, species-poor short-cut lawns and less intensively managed, near-natural tall-grass meadows. The higher conservation value of tall-grass meadows makes management interventions such as converting short-cut lawns into tall-grass meadows a promising tool for urban biodiversity conservation. The societal success of such interventions, however, depends on identifying the values urban residents assign to different types of urban grasslands, and how these values translate to attitudes towards greenspace management. Using 2027 questionnaires across 19 European cities, we identify the assigned values that correlate with people's personal greenspace use and their preferences for different types of urban grasslands to determine how these values relate to the agreement with a scenario of converting 50 of their cities� short-cut lawns into tall-grass meadows. We found that most people assigned nature-related values, such as wildness, to tall-grass meadows and utility-related values, such as recreation, to short-cut lawns. Positive value associations of wildness and species richness with tall-grass meadows, and social and nature-related greenspace activities, positively correlated with agreeing to convert short-cut lawns into tall-grass meadows. Conversely, disapproval of lawn conversion correlated with positive value associations of cleanliness and recreation potential with short-cut lawns. Here, people using greenspaces for nature-related activities were outstandingly positive about lawn conversion. The results show that the plurality of values assigned to different types of urban grasslands should be considered in urban greenspace planning. For example, tall-grass meadows could be managed to also accommodate the values associated with short-cut lawns, such as tidiness and recreation potential, to support their societal acceptance

Drivers of plant diversity in Bulgarian dry grasslands vary across spatial scales and functional-taxonomic groups

Questions: Studying dry grasslands in a previously unexplored region, we asked: (a) which environmental factors drive the diversity patterns in vegetation; (b) are taxonomic groups (vascular plants, bryophytes, lichens) and functional vascular plant groups differently affected; and (c) how is fine-grain beta diversity affected by environmental drivers? Location: Northwestern and Central Bulgaria. Methods: We sampled environmental data and vascular plant, terricolous bryophyte and lichen species in 97 10-m2 plots and 15 nested-plot series with seven grain sizes (0.0001–100 m2) of ten grassland sites within the two regions. We used species richness as measure of alpha-diversity and the z-value of the power-law species–area relationship as measure of beta-diversity. We analysed effects of landscape, topographic, soil and land-use variables on the species richness of the different taxonomic and functional groups. We applied generalised linear models (GLMs) or, in the presence of spatial autocorrelation, generalised linear mixed-effect models (GLMMs) in a multi-model inference framework. Results: The main factors affecting total and vascular plant species richness in 10-m2 plots were soil pH (unimodal) and inclination (negative). Species richness of bryophytes was positively affected by rock cover, sand proportion and negatively by inclination. Inclination and litter cover were also negative predictors of lichen species richness. Elevation negatively affected phanerophyte and therophyte richness, but positively that of cryptophytes. A major part of unexplained variance in species richness was associated with the grassland site. The z-values for total richness showed a positive relationship with elevation and inclination. Conclusions: Environmental factors shaping richness patterns strongly differed among taxonomic groups, functional vascular plant groups and spatial scales. The disparities between our and previous findings suggest that many drivers of biodiversity cannot be generalised but rather depend on the regional context. The large unexplained variance at the site level calls for considering more site-related factors such as land-use history

Are we talking about the same thing? Stakeholder perspectives on grassland management intensity

Grassland management crucially influences the delivery of ecosystem services from permanent grasslands. Variability in management practices is often described along a gradient from ‘low intensity’ to ‘high intensity’. These terms are likely to carry different meanings across European regions that differ inenvironmental and socio-economic conditions as well as between different groups of stakeholders. We conducted an online survey among grassland stakeholders asking them to characterise what they consider as ‘low’, ‘intermediate’ and ‘high’-intensity management in terms of cutting frequency, grazing intensity, and nitrogen fertilization. The answers of the 125 respondents revealed high variability in the thresholds between management intensity levels. Professional background (‘agriculture’ vs ‘ecology/ conservation’) explained only a small percentage of the variability. The biogeographical region on which the respondents’ expertise was based also influenced the evaluation of management practices. Our survey exposed the hidden problem of communicating about grassland management across regions and professional backgrounds, and identifies a need for a common terminology when making generalrecommendations for sustainable grassland management

Variability of European farming systems relying on permanent grasslands across biogeographic regions

The relevance of permanent grasslands (PG) for a large share of European farms is high, and yet understudied. We used single-farm records from the FADN (Farm Accountancy Data Network) database 2017, which included 41,926 farms-with-PG to characterize PG-based farming systems. Each farm wasassigned to one class in terms of: (1) main livestock species/category; (2) stocking rate on total farmland; (3) PG share; (4) biogeographic region (BGR). We carried out a Multi Correspondence Analysis (MCA) on the resulting classification, which explained 20% of the variance. The five BGR separated well in the first two MCA dimensions. Alpine farms were predominantly related to beef cattle, with relatively low stocking rates, and intermediate to high PG shares. Atlantic farms also revealed high PG shares, but were linked to higher stocking rates and ‘Mixed bovine’ and ‘Dairy cow’ farming. The dominance of farms without livestock in the Boreal BGR resulted in generally very low stocking rates and showed a limited importance of PG. Continental farms were not clearly related to one specific livestock category or a stocking rate, but consistently showed a share of 10-30% PG per farm. Finally, the Mediterranean BGR separated from the others, being dominated by sheep and goat farming