Assessing plant diversity and composition in grasslands across spatial scales: the standardised EDGG sampling methodology

This paper presents the details of the EDGG sampling methodology and its underlying rationales. The methodology has been applied during EDGG Research Expeditions and EDGG Field Workshops since 2009, and has been subsequently adopted by various other researchers. The core of the sampling are the EDGG Biodiversity Plots, which are 100‐m2 squares comprising, in two opposite corners, nested‐plot series of 0.0001, 0.001, 0.01, 0.1, 1 and 10 m2 square plots, in which all terricolous vascular plants, bryophytes and lichens are recorded using the shoot presence method. In the 10‐m2 plots, species cover is also estimated as a percentage and various environmental and structural parameters are recorded. Usually the EDGG Biodiversity Plots are complemented by the sampling of additional 10 m2 normal plots with the same parameters as the 10‐m2 corners of the first, allowing coverage of a greater environmental diversity and the achievement of higher statistical power in the subsequent analyses for this important grain size. The EDGG sampling methodology has been refined over the years, while its core has turned out to generate high‐quality, standardised data in an effective manner, which facilitates a multitude of analyses. In this paper we provide the current versions of our guidelines, field forms and data entry spreadsheets, as open‐access Online Resources to facilitate the easy implementation of this methodology by other researchers. We also discuss potential future additions and modifications to the approach, among which the most promising are the use of stratified‐random methods to a priori localise the plots and ideas to sample invertebrate taxa on the same plots and grain sizes, such as grasshoppers (Orthoptera) and vegetation‐dwelling spiders (Araneae). As with any other method, the EDGG sampling methodology is not ideal for every single purpose, but with its continuous improvements and its flexibility, it is a good multi‐ purpose approach. A particularly advantageous element, lacking in most other sampling schemes, including classical phytosociogical sampling, is the multi‐scale and multi‐taxon approach, which provides data that allow for deeper understanding of the generalities and idiosyncrasies of biodiversity patterns and their underlying drivers across scales and taxa

Scale-dependent plant diversity in Palaearctic grasslands: a comparative overview

Here we present an extensive overview of plant diversity values in Palaearctic grasslands for seven standard grain sizes from 0.0001 to 100 m². The data originate from 20 studies, including the Field Workshops of the Eurasian Dry Grassland Group (EDGG), ranging geographically from Spain in the west to Siberia in the east, from Sicily in the south to Estonia in the north and from the sea coast up to 3100 m a.s.l. The majority of data is from dry grasslands (Festuco-Brometea, Koelerio-Corynephoretea, Cleistogenetea squarrosae), but there are also some mesic, wet, saline, acidic, alpine and Mediterranean grasslands included. Among others, we compiled data from 1795 1-m², 1109 10-m² and 338 100-m² plots. In all cases we present mean, minimum and maximum richness for the seven grain sizes, plus, in cases where also terricolous bryophytes and lichens had been recorded, the same values for total “plant” species richness, non-vascular plant species richness and fraction of non-vascular plants. The maximum richness values were 82, 101 and 134 for all “plants”, and 79, 98 and 127 vascular plants at grain sizes of 1 m², 10 m² and 100 m², respectively (all in Transylvania, Romania). Our overview comprises new, hitherto unpublished world records of vascular plant species richness at the scales of 0.0001 m² (9) and 0.001 m² (19, both shoot presence), from meso-xeric, basiphilous grasslands in Navarre, Spain, which is much higher than the previously known maxima. The highest values of non-vascular plant richness at 1 m², 10 m² and 100 m², respectively, were 49, 64 and 64, respectively (all in Sedo-Scleranthenea communities of Öland, Sweden, and Saaremaa, Estonia). In general, the dry, alpine and Mediterranean grasslands were much richer than the studied mesic, wet or saline grasslands at any spatial scale. The presented set of mean, minimum and maximum values and their metadata is publically available and will be continuously updated. These data can serve as a reference of “normal” richness, both in fundamental and applied research. To facilitate the application, we provide an easy formula based on the power-law species-area relationship that allows the estimation of richness values at intermediate grain sizes not included in our dataset. In conclusion, our data emphasise the role of Palaearctic grasslands as global hotspot of small-scale vascular plant diversity, while at the same time highlighting that in some grassland types also the bryophyte and lichen diversity can be extraordinarily high

Benchmarking plant diversity of palaearctic grasslands and other open habitats

Funding information is provided in Appendix S7. We thank Manuel J. Steinbauer for the concept of the richness map in Figure 2. We thank the hundreds of vegetation ecologists who sampled the high-quality data used in this article and contributed them to GrassPlot.Biurrun, I; Pielech, R; Dembicz, I; Gillet, F; Kozub, L; Marceno, C; Reitalu, T; Van Meerbeek, K; Guarino, R; Chytry, M; Pakeman, RJ; Preislerova, Z; Axmanova, I; Burrascano, S; Bartha, S; Boch, S; Bruun, HH; Conradi, T; De Frenne, P; Essl, F; Filibeck, G; Hajek, M; Jimenez-Alfaro, B; Kuzemko, A; Molnar, Z; Partel, M; Patsch, R; Prentice, HC; Rolecek, J; Sutcliffe, LME; Terzi, M; Winkler, M; Wu, JS; Acic, S; Acosta, ATR; Afif, E; Akasaka, M; Alatalo, JM; Aleffi, M; Aleksanyan, A; Ali, A; Apostolova, I; Ashouri, P; Batori, Z; Baumann, E; Becker, T; Belonovskaya, E; Alonso, JLB; Berastegi, A; Bergamini, A; Bhatta, KP; Bonini, I; Buchler, MO; Budzhak, V; Bueno, A; Buldrini, F; Campos, JA; Cancellieri, L; Carboni, M; Ceulemans, T; Chiarucci, A; Chocarro, C; Conti, L; Csergo, AM; Cykowska-Marzencka, B; Czarniecka-Wiera, M; Czarnocka-Cieciura, M; Czortek, P; Danihelka, J; Bello, F; Deak, B; Demeter, L; Deng, L; Diekmann, M; Dolezal, J; Dolnik, C; Drevojan, P; Dupre, C; Ecker, K; Ejtehadi, H; Erschbamer, B; Etayo, J; Etzold, J; Farkas, T; Farzam, M; Fayvush, G; Calzado, MRF; Finckh, M; Fjellstad, W; Fotiadis, G; Garcia-Magro, D; Garcia-Mijangos, I; Gavilan, RG; Germany, M; Ghafari, S; del Galdo, GPG; Grytnes, JA; Guler, B; Gutierrez-Giron, A; Helm, A; Herrera, M; Hullbusch, EM; Ingerpuu, N; Jagerbrand, AK; Jandt, U; Janisova, M; Jeanneret, P; Jeltsch, F; Jensen, K; Jentsch, A; Kacki, Z; Kakinuma, K; Kapfer, J; Kargar, M; Kelemen, A; Kiehl, K; Kirschner, P; Koyama, A; Langer, N; Lazzaro, L; Leps, J; Li, CF; Li, FY; Liendo, D; Lindborg, R; Lobel, S; Lomba, A; Lososova, Z; Lustyk, P; Luzuriaga, AL; Ma, WH; Maccherini, S; Magnes, M; Malicki, M; Manthey, M; Mardari, C; May, F; Mayrhofer, H; Meier, ES; Memariani, F; Merunkova, K; Michelsen, O; Mesa, JM; Moradi, H; Moysiyenko, I; Mugnai, M; Naqinezhad, A; Natcheva, R; Ninot, JM; Nobis, M; Noroozi, J; Nowak, A; Onipchenko, V; Palpurina, S; Pauli, H; Pedashenko, H; Pedersen, C; Peet, RK; Perez-Haase, A; Peters, J; Pipenbaher, N; Pirini, C; Pladevall-Izard, E; Pleskova, Z; Potenza, G; Rahmanian, S; Rodriguez-Rojo, MP; Ronkin, V; Rosati, L; Ruprecht, E; Rusina, S; Sabovljevic, M; Sanaei, A; Sanchez, AM; Santi, F; Savchenko, G; Sebastia, MT; Shyriaieva, D; Silva, V; Skornik, S; Smerdova, E; Sonkoly, J; Sperandii, MG; Staniaszek-Kik, M; Stevens, C; Stifter, S; Suchrow, S; Swacha, G; Swierszcz, S; Talebi, A; Teleki, B; Tichy, L; Tolgyesi, C; Torca, M; Torok, P; Tsarevskaya, N; Tsiripidis, I; Turisova, I; Ushimaru, A; Valko, O; Van Mechelen, C; Vanneste, T; Vasheniak, I; Vassilev, K; Viciani, D; Villar, L; Virtanen, R; Vitasovic-Kosic, I; Vojtko, A; Vynokurov, D; Walden, E; Wang, Y; Weiser, F; Wen, L; Wesche, K; White, H; Widmer, S; Wolfrum, S; Wrobel, A; Yuan, ZQ; Zeleny, D; Zhao, LQ; Dengler,

Biodiversity surveys of grassland and coastal habitats in 2021 as a documentation of pre-war status in southern Ukraine

Background This paper presents two sampling-event datasets with occurrences of vascular plants, bryophytes and lichens collected in May-June 2021 in southern Ukraine. We aimed to collect high-quality biodiversity data in an understudied region and contribute it to international databases and networks. The study was carried out during the 15th Eurasian Dry Grassland Group (EDGG) Field Workshop in southern Ukraine and the Dark Diversity Network (DarkDivNet) sampling in the Kamianska Sich National Nature Park. By chance, these datasets were collected shortly before the major escalation of the Russian invasion in Ukraine. Surveyed areas in Kherson and Mykolaiv Regions, including established monitoring plots, were severely affected by military actions in 2022. Therefore, collected data are of significant value in the context of biodiversity documentation. The knowledge about the biodiversity of this area will help to assess the environmental impact of the war and plan restoration of the damaged or destroyed habitats. The first preliminary analysis of collected data demonstrates the biodiversity richness and conservation value of studied grassland habitats. New information We provide sampling-event datasets with 7467 occurrences, which represent 708 taxa (vascular plants, bryophytes and lichens) collected in 275 vegetation relevés. Amongst them, vascular plants are represented by 6665 occurrences (610 taxa), lichens - 420 (46) and bryophytes - 381 (51). Several new species were reported for the first time at the national or regional level. In particular, one vascular plant species (Torilis pseudonodosa) and two lichen species (Cladonia conista, Endocarpon loscosii) were new to Ukraine. One vascular plant (Stipa tirsa), two species of bryophytes (Rhynchostegium megapolitanum, Ptychostomum torquescens) and three species of lichens (Cladonia cervicornis, C. symphycarpa, Involucropyrenium breussi) were recorded for the first time for the Kherson Region. Additionally, these datasets contain occurrences of taxa with narrow distribution, specialists of rare habitat types and, therefore, represented by a low number of occurrences in relevant biodiversity databases and particularly in GBIF. This publication highlights the diversity of natural vegetation and its flora in southern Ukraine and raises conservation concerns

Plant species richness records in Ukrainian steppes

We compiled a list of the known maxima of vascular plant species richness in the steppe zone of Ukraine at different sampling scales (0.0001–100 m2) and compared them with the world records. Detailed information on each of the identified species-rich grassland plots is provided, including site descriptions, plot characteristics, coordinates, and species lists. Most of the small-scale records (up to 0.1 m2) were found in mesic grasslands in southern Ukraine (Kherson region) with a high abundance of annual grasses and forbs: 9 and 11 vascular plant species in 0.0001 m2 and 0.001 m2, respectively, in the steppe depression Chorna Dolyna, and 26 species in 0.1 m2 in a mesic psammophytic grassland in the Dzharylhach National Nature Park. Most of the records at larger scales were made in the northern part of the steppe zone, in forb-rich and forb-grass steppes: 15, 39, 73, and 107 species in 0.01, 1, 10, and 100 m2, respectively. All richness records were characterised by neutral to slightly alkaline sub-strates (soil pH 7.0–7.7) and low-intensity management. These characteristics are consistent with the known patterns from world records of species richness. Our inventory provides baseline knowledge for studies on the high species richness in the steppe zone and can stimulate the further investigation of identified species-rich grasslands, as well as the search for new ones. Since we did not specifically search for species-rich sites, and our dataset includes only a relatively small number of plots compared to similar studies in other regions, we expect that more species-rich vegetation will be found with further research. This study highlights the importance of steppe grasslands as global biodiversity hotspots and draws attention to their protection in the context of land-use changes and the consequences of the war in Ukraine

Drivers of vascular plant, bryophyte and lichen richness in grasslands along a precipitation gradient (central Apennines, Italy)

Questions: Semi-natural grasslands in Southern Europe are biodiversity hotspots, yet their patterns of plant species richness are less studied than in Central Europe. In the Central Apennines (Italy), there are large areas of dry calcareous grasslands, across a steep gradient of mean annual precipitation (from 650 to 1350 mm within c. 30 km). We asked: How do these grasslands compare to other Palaearctic grasslands in richness levels? How do the precipitation gradient and other environmental predictors influence species richness? Does this influence differ among taxonomic groups? Location: Submontane and lower-montane belt of the Central Apennines (Abruzzo and Lazio, Italy). Methods: We recorded the species richness of vascular plants and (terricolous) bryophytes and lichens in 97 plots of 10 m2, aligning them with the precipitation gradient while maintaining geological substrate and elevation similar. Mean temperature and precipitation were estimated with a high-resolution regional model. A wide array of environmental variables (including soil properties and grazing load) were measured for each plot. Multivariate relationships within and between response and predictor variables were studied with Canonical Correlation. The relative importance of predictors on response variables was modeled with Boosted Regression Trees

ReSurveyEurope: A database of resurveyed vegetation plots in Europe

Aims: We introduce ReSurveyEurope - a new data source of resurveyed vegetation plots in Europe, compiled by a collaborative network of vegetation scientists. We describe the scope of this initiative, provide an overview of currently available data, governance, data contribution rules, and accessibility. In addition, we outline further steps, including potential research questions. Results: ReSurveyEurope includes resurveyed vegetation plots from all habitats. Version 1.0 of ReSurveyEurope contains 283,135 observations (i.e., individual surveys of each plot) from 79,190 plots sampled in 449 independent resurvey projects. Of these, 62,139 (78%) are permanent plots, that is, marked in situ, or located with GPS, which allow for high spatial accuracy in resurvey. The remaining 17,051 (22%) plots are from studies in which plots from the initial survey could not be exactly relocated. Four data sets, which together account for 28,470 (36%) plots, provide only presence/absence information on plant species, while the remaining 50,720 (64%) plots contain abundance information (e.g., percentage cover or cover-abundance classes such as variants of the Braun-Blanquet scale). The oldest plots were sampled in 1911 in the Swiss Alps, while most plots were sampled between 1950 and 2020. Conclusions: ReSurveyEurope is a new resource to address a wide range of research questions on fine-scale changes in European vegetation. The initiative is devoted to an inclusive and transparent governance and data usage approach, based on slightly adapted rules of the well-established European Vegetation Archive (EVA). ReSurvey:Europe data are ready for use, and proposals for analyses of the data set can be submitted at any time to the coordinators. Still, further data contributions are highly welcome

ReSurveyEurope: A database of resurveyed vegetation plots in Europe

Aims: We introduce ReSurveyEurope - a new data source of resurveyed vegetation plots in Europe, compiled by a collaborative network of vegetation scientists. We describe the scope of this initiative, provide an overview of currently available data, governance, data contribution rules, and accessibility. In addition, we outline further steps, including potential research questions. Results: ReSurveyEurope includes resurveyed vegetation plots from all habitats. Version 1.0 of ReSurveyEurope contains 283,135 observations (i.e., individual surveys of each plot) from 79,190 plots sampled in 449 independent resurvey projects. Of these, 62,139 (78%) are permanent plots, that is, marked in situ, or located with GPS, which allow for high spatial accuracy in resurvey. The remaining 17,051 (22%) plots are from studies in which plots from the initial survey could not be exactly relocated. Four data sets, which together account for 28,470 (36%) plots, provide only presence/absence information on plant species, while the remaining 50,720 (64%) plots contain abundance information (e.g., percentage cover or cover-abundance classes such as variants of the Braun-Blanquet scale). The oldest plots were sampled in 1911 in the Swiss Alps, while most plots were sampled between 1950 and 2020. Conclusions: ReSurveyEurope is a new resource to address a wide range of research questions on fine-scale changes in European vegetation. The initiative is devoted to an inclusive and transparent governance and data usage approach, based on slightly adapted rules of the well-established European Vegetation Archive (EVA). ReSurvey:Europe data are ready for use, and proposals for analyses of the data set can be submitted at any time to the coordinators. Still, further data contributions are highly welcome

Global impoverishment of natural vegetation revealed by dark diversity

Anthropogenic biodiversity decline threatens the functioning of ecosystems and the many benefits they provide to humanity1. As well as causing species losses in directly affected locations, human influence might also reduce biodiversity in relatively unmodified vegetation if far-reaching anthropogenic effects trigger local extinctions and hinder recolonization. Here we show that local plant diversity is globally negatively related to the level of anthropogenic activity in the surrounding region. Impoverishment of natural vegetation was evident only when we considered community completeness: the proportion of all suitable species in the region that are present at a site. To estimate community completeness, we compared the number of recorded species with the dark diversity—ecologically suitable species that are absent from a site but present in the surrounding region2. In the sampled regions with a minimal human footprint index, an average of 35% of suitable plant species were present locally, compared with less than 20% in highly affected regions. Besides having the potential to uncover overlooked threats to biodiversity, dark diversity also provides guidance for nature conservation. Species in the dark diversity remain regionally present, and their local populations might be restored through measures that improve connectivity between natural vegetation fragments and reduce threats to population persistence