Browsing by Author "Dengler J."
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Item Festuco-Brometea communities of the Transylvanian Plateau (Romania) - A preliminary overview on syntaxonomy, ecology, and biodiversity(Floristisch - Soziologische Arbeitsgemeinschaft, 2012) Dengler J.; Becker T.; Ruprecht E.; Szabó A.; Becker U.; Beldean M.; Bita-Nicolae C.; Dolnik C.; Goia I.; Peyrat J.; Sutcliffe L.M.; Turtureanu P.D.; Uǧurlu E.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 α-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 β-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.Item Dry grassland vegetation of central Podolia (Ukraine) - A preliminary overview of its syntaxonomy, ecology and biodiversity(Floristisch - Soziologische Arbeitsgemeinschaft, 2014) Kuzemko A.A.; Becker T.; Didukh Y.P.; Ardelean I.V.; Becker U.; Beldean M.; Dolnik C.; Jeschke M.; Naqinezhad A.; Uğurlu E.; Ünal A.; Vassilev K.; Vorona E.I.; Yavorska O.H.; Dengler J.We present the data of the 2nd research expedition of the European Dry Grassland Group (EDGG), which was conducted in 2010 in Central Podolia, Ukraine. The aim was to collect plot data to compare Ukrainian dry grasslands with those of other parts of Europe in terms of syntaxonomy and biodiversity. We sampled 21 nested-plot series (0.0001-100 m2) and 184 normal plots (10 m2) covering the full variety of dry grassland types occurring in the study region. For all plots, we recorded species composition of terrestrial vascular plants, bryophytes and lichens, while for the 226 10-m2 plots we estimated and measured percentage cover of all species, structural, topographic, soil and landuse parameters. The 10-m2 plots were used for phytosociological classification based on iteratively refined TWINSPAN classification as well as for DCA ordination. Differences between the derived vegetation types with respect to environmental conditions and species richness were assessed with ANOVAs. We assigned our plots to nine association-level units but refrained from placing them into formal associations with two exceptions. In the study area, dry grasslands of the Festuco-Brometea were far more common than those of the Koelerio-Corynephoretea. Among the Festuco-Brometea, xeric Festucetalia valesiacae grasslands were more frequent and represented by the Festucion valesiacae (2 associations, including the Allio taurici-Dichanthietum ischaemi ass. nova) and the Stipion lessingianae (1) compared to the Brachypodietalia pinnati with the Agrostio vinealis-Avenulion schellianae (3). The Koelerio-Corynephoretea were represented by three associations, each from a different order and alliance: basiphilous outcrops (Alysso alyssoidis-Sedetalia: Alysso alyssoidis-Sedion?), acidophilous outcrops (Sedo-Scleranthetalia: Veronico dillenii-Sedion albi?) and mesoxeric sandy grasslands (Trifolio arvensis-Festucetalia ovinae: Agrostion vinealis). We discuss the issue of the mesoxeric order Galietalia veri placed within the Molinio-Arrhenatheretea by Ukrainian authors and conclude that the content of that order would probably be better placed in the mesoxeric orders of the Koelerio-Corynephoretea and Festuco-Brometea. Other syntaxonomic questions could not be solved with our geographically limited dataset and await a supraregional analysis, e.g. whether the Ukrainian outcrop communities should be assigned to the same alliances as known from Central Europe or rather represent new vicariant units. The analysis of the biodiversity patterns showed that at a grain size of 10 m2, Podolian Koelerio-Corynephoretea communities were overall richer than Festuco-Brometea communities (46.4 vs. 40.6 species). This difference was due to the Koelerio-Corynephoretea containing twice as many bryophytes and nine times more lichens, while vascular plant species richness did not differ significantly between classes. The orders within the classes showed no real differences in species richness. The richness patterns observed in Podolia were almost the opposite of those usually found in dry grasslands, where Brachypodietalia pinnati are richer than Festucetalia valesiacae, and these richer than stands of the Koelerio-Corynpehoretea - and we do not have a good explanation for these idiosyncrasies. In conclusion, Podolian dry grasslands behave quite unexpectedly regarding biodiversity, and their syntaxonomy is still poorly understood. These knowledge gaps can only be addressed with supra-national analyses based on comprehensive datasets.Item European Vegetation Archive (EVA): An integrated database of European vegetation plots(Wiley-Blackwell, 2016) Chytrý M.; Hennekens S.M.; Jiménez-Alfaro B.; Knollová I.; Dengler J.; Jansen F.; Landucci F.; Schaminée J.H.J.; Aćić S.; Agrillo E.; Ambarli D.; Angelini P.; Apostolova I.; Attorre F.; Berg C.; Bergmeier E.; Biurrun I.; Botta-Dukát Z.; Brisse H.; Campos J.A.; Carlón L.; Čarni A.; Casella L.; Csiky J.; Ćušterevska R.; Dajić Stevanović Z.; Danihelka J.; De Bie E.; de Ruffray P.; De Sanctis M.; Dickoré W.B.; Dimopoulos P.; Dubyna D.; Dziuba T.; Ejrnæs R.; Ermakov N.; Ewald J.; Fanelli G.; Fernández-González F.; Fitzpatrick U.; Font X.; García-Mijangos I.; Gavilán R.G.; Golub V.; Guarino R.; Haveman R.; Indreica A.; Işik Gürsoy D.; Jandt U.; Janssen J.A.M.; Jiroušek M.; Kacki Z.; Kavgaci A.; Kleikamp M.; Kolomiychuk V.; Krstivojević Ćuk M.; Krstonošić D.; Kuzemko A.; Lenoir J.; Lysenko T.; Marcenò C.; Martynenko V.; Michalcová D.; Moeslund J.E.; Onyshchenko V.; Pedashenko H.; Pérez-Haase A.; Peterka T.; Prokhorov V.; Rašomavičius V.; Rodríguez-Rojo M.P.; Rodwell J.S.; Rogova T.; Ruprecht E.; Rusiņa S.; Seidler G.; Šibík J.; Šilc U.; Škvorc Z.; Sopotlieva D.; Stančić Z.; Svenning J.-C.; Swacha G.; Tsiripidis I.; Turtureanu P.D.; Uğurlu E.; Uogintas D.; Valachovič M.; Vashenyak Y.; Vassilev K.; Venanzoni R.; Virtanen R.; Weekes L.; Willner W.; Wohlgemuth T.; Yamalov S.The European Vegetation Archive (EVA) is a centralized database of European vegetation plots developed by the IAVS Working Group European Vegetation Survey. It has been in development since 2012 and first made available for use in research projects in 2014. It stores copies of national and regional vegetation- plot databases on a single software platform. Data storage in EVA does not affect on-going independent development of the contributing databases, which remain the property of the data contributors. EVA uses a prototype of the database management software TURBOVEG 3 developed for joint management of multiple databases that use different species lists. This is facilitated by the SynBioSys Taxon Database, a system of taxon names and concepts used in the individual European databases and their corresponding names on a unified list of European flora. TURBOVEG 3 also includes procedures for handling data requests, selections and provisions according to the approved EVA Data Property and Governance Rules. By 30 June 2015, 61 databases from all European regions have joined EVA, contributing in total 1 027 376 vegetation plots, 82% of them with geographic coordinates, from 57 countries. EVA provides a unique data source for large-scale analyses of European vegetation diversity both for fundamental research and nature conservation applications. Updated information on EVA is available online at http://euroveg.org/eva-database. © 2016 International Association for Vegetation Science.Item How plot shape and spatial arrangement affect plant species richness counts: implications for sampling design and rarefaction analyses(Wiley-Blackwell, 2016) Güler B.; Jentsch A.; Apostolova I.; Bartha S.; Bloor J.M.G.; Campetella G.; Canullo R.; Házi J.; Kreyling J.; Pottier J.; Szabó G.; Terziyska T.; Uğurlu E.; Wellstein C.; Zimmermann Z.; Dengler J.Questions: How does the spatial configuration of sampling units influence recorded plant species richness values at small spatial scales? What are the consequences of these findings for sampling methodology and rarefaction analyses?. Location: Six semi-natural grasslands in Western Eurasia (France, Germany, Bulgaria, Hungary, Italy, Turkey). Methods: In each site we established six blocks of 40 cm × 280 cm, subdivided into 5 cm × 5 cm micro-quadrats, on which we recorded vascular plant species presence with the rooted (all sites) and shoot (four sites) presence method. Data of these micro-quadrats were then combined to achieve larger sampling units of 0.01, 0.04 and 0.16 m² grain size with six different spatial configurations (square, 4:1 rectangle, 16:1 rectangle, three variants of discontiguous randomly placed micro-quadrats). The effect of the spatial configurations on species richness was quantified as relative richness compared to the mean richness of the square of the same surface area. Results: Square sampling units had significantly lower species richness than other spatial configurations in all countries. For 4:1 and 16:1 rectangles, the increase of rooted richness was on average about 2% and 8%, respectively. In contrast, the average richness increase for discontiguous configurations was 7%, 17% and 40%. In general, increases were higher with shoot presence than with rooted presence. Overall, the patterns of richness increase were highly consistent across six countries, three grain sizes and two recording methods. Conclusions: Our findings suggest that the shape of sampling units has negligible effects on species richness values when the length–width ratio is up to 4:1, and the effects remain small even for more elongated contiguous configurations. In contrast, results from discontiguous sampling units are not directly comparable with those of contiguous sampling units, and are strongly confounded by spatial extent. This is particularly problematic for rarefaction studies where spatial extent is often not controlled for. We suggest that the concept of effective area is a useful tool to report effects of spatial configuration on richness values, and introduce species–extent relationships (SERs) to describe richness increases of different spatial configurations of sampling units. © 2016 International Association for Vegetation ScienceItem Patterns and drivers of phytodiversity in steppe grasslands of Central Podolia (Ukraine)(Springer Netherlands, 2016) Kuzemko A.A.; Steinbauer M.J.; Becker T.; Didukh Y.P.; Dolnik C.; Jeschke M.; Naqinezhad A.; Uğurlu E.; Vassilev K.; Dengler J.We asked: (i) Which environmental factors determine the level of α-diversity at several scales and β-diversity in steppic grasslands? (ii) How do the effects of environmental factors on α- and β-diversity vary between the different taxonomic groups (vascular plants, bryophytes, lichens)? We sampled nested-plot series ranging from 0.0001 to 100 m2 and additional 10-m2 plots, covering different vegetation types and management regimes in steppes and semi-natural dry grasslands of Central Podolia (Ukraine). We recorded all terricolous taxa and used topographic, soil, land-use and climatic variables as predictors. Richness-environment relationships at different scales and across taxonomic groups were assessed with multimodel inference. We also fitted power-law species-area relationships, using the exponent (z value) as a measure of β-diversity. In general, the richness values in the study region were intermediate compared to those known from similar grasslands throughout the Palaearctic, but for 1 cm2 we found seven species of vascular plants, a new world record. Heat index was the most important factor for vascular plants and bryophytes (negative relation), while lichen diversity depended mainly on stone and rock cover (positive). The explanatory power of climate-related variables increased with increasing grain size, while anthropogenic burning was the most important factor for richness patterns at the finest grain sizes (positive effect). The z values showed more variation at the finest grain sizes, but no significant differences in their mean between scales. The results highlight the importance of integrating scale into ecological analyses and nature conservation assessments in order to understand and manage biological diversity in steppe ecosystems. © 2016, Springer Science+Business Media Dordrecht.Item Species richness effects on grassland recovery from drought depend on community productivity in a multisite experiment(Blackwell Publishing Ltd, 2017) Kreyling J.; Dengler J.; Walter J.; Velev N.; Ugurlu E.; Sopotlieva D.; Ransijn J.; Picon-Cochard C.; Nijs I.; Hernandez P.; Güler B.; von Gillhaussen P.; De Boeck H.J.; Bloor J.M.G.; Berwaers S.; Beierkuhnlein C.; Arfin Khan M.A.S.; Apostolova I.; Altan Y.; Zeiter M.; Wellstein C.; Sternberg M.; Stampfli A.; Campetella G.; Bartha S.; Bahn M.; Jentsch A.Biodiversity can buffer ecosystem functioning against extreme climatic events, but few experiments have explicitly tested this. Here, we present the first multisite biodiversity × drought manipulation experiment to examine drought resistance and recovery at five temperate and Mediterranean grassland sites. Aboveground biomass production declined by 30% due to experimental drought (standardised local extremity by rainfall exclusion for 72–98 consecutive days). Species richness did not affect resistance but promoted recovery. Recovery was only positively affected by species richness in low-productive communities, with most diverse communities even showing overcompensation. This positive diversity effect could be linked to asynchrony of species responses. Our results suggest that a more context-dependent view considering the nature of the climatic disturbance as well as the productivity of the studied system will help identify under which circumstances biodiversity promotes drought resistance or recovery. Stability of biomass production can generally be expected to decrease with biodiversity loss and climate change. © 2017 John Wiley & Sons Ltd/CNRSItem sPlot – A new tool for global vegetation analyses(Wiley-Blackwell, 2019) Bruelheide H.; Dengler J.; Jiménez-Alfaro B.; Purschke O.; Hennekens S.M.; Chytrý M.; Pillar V.D.; Jansen F.; Kattge J.; Sandel B.; Aubin I.; Biurrun I.; Field R.; Haider S.; Jandt U.; Lenoir J.; Peet R.K.; Peyre G.; Sabatini F.M.; Schmidt M.; Schrodt F.; Winter M.; Aćić S.; Agrillo E.; Alvarez M.; Ambarlı D.; Angelini P.; Apostolova I.; Arfin Khan M.A.S.; Arnst E.; Attorre F.; Baraloto C.; Beckmann M.; Berg C.; Bergeron Y.; Bergmeier E.; Bjorkman A.D.; Bondareva V.; Borchardt P.; Botta-Dukát Z.; Boyle B.; Breen A.; Brisse H.; Byun C.; Cabido M.R.; Casella L.; Cayuela L.; Černý T.; Chepinoga V.; Csiky J.; Curran M.; Ćušterevska R.; Dajić Stevanović Z.; De Bie E.; de Ruffray P.; De Sanctis M.; Dimopoulos P.; Dressler S.; Ejrnæs R.; El-Sheikh M.A.E.-R.M.; Enquist B.; Ewald J.; Fagúndez J.; Finckh M.; Font X.; Forey E.; Fotiadis G.; García-Mijangos I.; de Gasper A.L.; Golub V.; Gutierrez A.G.; Hatim M.Z.; He T.; Higuchi P.; Holubová D.; Hölzel N.; Homeier J.; Indreica A.; Işık Gürsoy D.; Jansen S.; Janssen J.; Jedrzejek B.; Jiroušek M.; Jürgens N.; Kącki Z.; Kavgacı A.; Kearsley E.; Kessler M.; Knollová I.; Kolomiychuk V.; Korolyuk A.; Kozhevnikova M.; Kozub Ł.; Krstonošić D.; Kühl H.; Kühn I.; Kuzemko A.; Küzmič F.; Landucci F.; Lee M.T.; Levesley A.; Li C.-F.; Liu H.; Lopez-Gonzalez G.; Lysenko T.; Macanović A.; Mahdavi P.; Manning P.; Marcenò C.; Martynenko V.; Mencuccini M.; Minden V.; Moeslund J.E.; Moretti M.; Müller J.V.; Munzinger J.; Niinemets Ü.; Nobis M.; Noroozi J.; Nowak A.; Onyshchenko V.; Overbeck G.E.; Ozinga W.A.; Pauchard A.; Pedashenko H.; Peñuelas J.; Pérez-Haase A.; Peterka T.; Petřík P.; Phillips O.L.; Prokhorov V.; Rašomavičius V.; Revermann R.; Rodwell J.; Ruprecht E.; Rūsiņa S.; Samimi C.; Schaminée J.H.J.; Schmiedel U.; Šibík J.; Šilc U.; Škvorc Ž.; Smyth A.; Sop T.; Sopotlieva D.; Sparrow B.; Stančić Z.; Svenning J.-C.; Swacha G.; Tang Z.; Tsiripidis I.; Turtureanu P.D.; Uğurlu E.; Uogintas D.; Valachovič M.; Vanselow K.A.; Vashenyak Y.; Vassilev K.; Vélez-Martin E.; Venanzoni R.; Vibrans A.C.; Violle C.; Virtanen R.; von Wehrden H.; Wagner V.; Walker D.A.; Wana D.; Weiher E.; Wesche K.; Whitfeld T.; Willner W.; Wiser S.; Wohlgemuth T.; Yamalov S.; Zizka G.; Zverev A.Aims: Vegetation-plot records provide information on the presence and cover or abundance of plants co-occurring in the same community. Vegetation-plot data are spread across research groups, environmental agencies and biodiversity research centers and, thus, are rarely accessible at continental or global scales. Here we present the sPlot database, which collates vegetation plots worldwide to allow for the exploration of global patterns in taxonomic, functional and phylogenetic diversity at the plant community level. Results: sPlot version 2.1 contains records from 1,121,244 vegetation plots, which comprise 23,586,216 records of plant species and their relative cover or abundance in plots collected worldwide between 1885 and 2015. We complemented the information for each plot by retrieving climate and soil conditions and the biogeographic context (e.g., biomes) from external sources, and by calculating community-weighted means and variances of traits using gap-filled data from the global plant trait database TRY. Moreover, we created a phylogenetic tree for 50,167 out of the 54,519 species identified in the plots. We present the first maps of global patterns of community richness and community-weighted means of key traits. Conclusions: The availability of vegetation plot data in sPlot offers new avenues for vegetation analysis at the global scale. © 2019 International Association for Vegetation Science