Long Database Report |
Corresponding author: Jürgen Dengler ( dr.juergen.dengler@gmail.com ) Academic editor: Florian Jansen
© 2024 Nadiia Skobel, Łukasz Kozub, Iwona Dembicz, Steffen Boch, Hans Henrik Bruun, Olha Chusova, Valentin Golub, Aveliina Helm, Dmytro Iakushenko, Paweł Pawlikowski, Piotr Zaniewski, Jürgen Dengler.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Skobel N, Kozub Ł, Dembicz I, Boch S, Bruun HH, Chusova O, Golub V, Helm A, Iakushenko D, Pawlikowski P, Zaniewski P, Dengler J (2024) Nordic-Baltic Grassland Vegetation Database (NBGVD) – current state and future prospects. Vegetation Classification and Survey 5: 75-84. https://doi.org/10.3897/VCS.119968
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This Long Database Report describes the historical background and current contents of the Nordic-Baltic Grassland Vegetation Database (NBGVD) (GIVD-code EU-00-002). NBGVD is the EDGG-associated collaborative vegetation-plot database that collects vegetation-plot data of grasslands and other open habitats (except segetal and deep aquatic vegetation) from the Nordic-Baltic region excluding Germany, namely Belarus, Denmark, Estonia, Faroe Islands, Finland, Iceland, Latvia, Lithuania, Norway, N Poland, NW Russia, Svalbard and Jan Mayen, and Sweden. Target vegetation types are lowland grasslands and heathlands, arctic-alpine communities, coastal communities, non-forested mires and other wetlands, rocky, tall-herb and ruderal communities. As of March 2024, it included 12,694 relevés recorded between 1910 and 2023. These were mainly digitised from literature sources (84%), while the remainder comes from individual unpublished sources (16%). The data quality is high, with bryophytes and lichens being treated in more than 80% of all plots and measured environmental variables such as topography and soil characteristics often available in standardised form. A peculiarity of the Nordic-Baltic region are the relatively small plot sizes compared to other regions (median: 4 m2). The available data stem from 35 vegetation classes, with Koelerio-Corynephoretea, Festuco-Brometea, Sedo-Scleranthetea, Molinio-Arrhenatheretea and Scheuchzerio-Caricetea being most frequent. We conclude that NBGVD provides valuable data, allowing interesting analyses at the regional scale and fills gaps in continental to global analyses. Still, since there are many more data around, we ask interested readers to contribute their own data or help find and digitise old data from the literature.
Taxonomic reference: TURBOVEG species list “Europe”.
Syntaxonomic reference:
Abbreviations: EDGG = Eurasian Dry Grassland Group, EVA = European Vegetation Archive, GIVD = Global Index of Vegetation-Plot Databases, NBGVD = Nordic-Baltic Grassland Vegetation Database
Arctic-alpine vegetation, Baltic region, coastal vegetation, ecoinformatics, European Vegetation Archive (EVA), grassland, macroecology, mire, Nordic region, plot size, relevé, vegetation-plot database
Vegetation-plot databases have an enormous potential for vegetation ecology, macroecology and global-change studies (
In addition, most of the Nordic-Baltic countries (except Germany and Poland) do not have a strong phytosociological tradition as they were in the realms of the Russian (
The Nordic and Baltic region in the sense of NBGVD is defined as the combined territories of Denmark, Faroe Islands, Iceland, Svalbard and Jan Mayen, Norway, Sweden, Finland, NW Russia, Belarus, Estonia, Latvia, Lithuania and the Pleistocene lowlands of N Poland and N Germany. This region approximately corresponds to the maximum extension of the Northern European ice shield during the Pleistocene (Lang 1994). However, German plots have recently been excluded from NBGVD and transferred to our sister database GrassVeg.DE (
According to its Bylaws, NBGVD’s main foci are “all natural and semi-natural grasslands s.l.”. However, any vegetation types except forests, shrublands, true aquatic communities and arable fields are collected. According to
Further, the relevés must refer to contiguous plots with a specified area in the range of 0.09 to 400 m2. Relevés with a direct estimate of percent cover (see
The database originated from data collected by J. Dengler aimed at the phytosociological classification of the dry grasslands of the region, at that time managed in the software for vegetation plot handling SORT (
NBGVD is a self-governed consortium in which every data contributor becomes a member. It is regulated by a set of Bylaws (Suppl. material
Starting with 7,675 plots in 2012 (
Currently, the database is managed using the latest version of the TURBOVEG 2.0 software (
The 12,694 vegetation plots currently included in NBGVD originate from data published by consortium members (19.5%) and other authors (45.6%), while the rest are unpublished relevés from consortium members (34.9%). In total, the NBGVD currently contains data from 124 different sources (Suppl. material
NBGVD has data from all 13 countries or territories within its geographic scope, with the numbers being highest in the Polish lowlands (24.8%) and Sweden (24.6%), followed by Belarus (12.9%) and Estonia (10.3%) (Table
The data were collected from 1910 to 2023 (median: 1997), with a peak in the two decades from 1990 to 2009, but otherwise with rather uniform distribution (Figure
Where this information is available, NBGVD stores the association/community, alliance, and order assignment of the vegetation plots in the source, without attempting harmonization. Moreover, more than 75% of the plots in NBGVD are currently assigned to a vegetation class according to Mucina et al. (
NBGVD also contains various header data fields for structural and environmental variables. Apart from several environmental header data fields with free text, such as land use and soil texture class, there are currently 11 measured environmental variables referring to topography and soil characteristics (Table
It is worth mentioning that according to the header data, bryophytes were treated in nearly 86% of the plots and lichens in 83% of the plots in the database, meaning that NBGVD can provide real absences of non-vascular taxa. The five most frequent vascular plant taxa (after merging taxa determined at different levels across plots into some broader concepts) are Festuca ovina aggr. (30.6% of the plots), Achillea millefolium aggr. (28.9%), Galium verum (25.2%), Hieracium pilosella aggr. (23.5%), and Festuca rubra aggr. (23.4%) (Suppl. material
Countries and other territories covered by NBGVD with their area and available plot number in March 2024, expressed in absolute and relative terms and density per surface area.
Country or part of country | Area included [km2] | Number of plots | Fraction [%] | Plot density [plots/1,000 km2] |
---|---|---|---|---|
Belarus | 207,595 | 1,632 | 12.9 | 7.9 |
Denmark (mainland) | 43,094 | 214 | 1.7 | 5.0 |
Estonia | 45,339 | 1,309 | 10.3 | 28.9 |
Faroe Islands | 1,398 | 720 | 5.7 | 515.0 |
Finland | 338,145 | 222 | 1.7 | 0.7 |
Iceland | 103,125 | 460 | 3.6 | 4.5 |
Latvia | 64,589 | 280 | 2.2 | 4.3 |
Lithuania | 65,300 | 127 | 1.0 | 1.9 |
Norway (mainland) | 324,220 | 716 | 5.6 | 2.2 |
Poland (lowlands) | 230,107 | 3,149 | 24.8 | 13.7 |
Russia (NW part) | 956,305 | 158 | 1.2 | 0.2 |
Svalbard and Jan Mayen | 62,045 | 587 | 4.6 | 9.5 |
Sweden | 450,295 | 3,120 | 24.6 | 6.9 |
Total | 2,891,557 | 12,694 | 100.0 | 4.4 |
Measured environmental variables contained in NBGVD with their degree of availability and the distribution of values.
Variable | Unit | TURBOVEG name | Available (%) | Min | Max | Mean | Median |
---|---|---|---|---|---|---|---|
Elevation | m a.s.l. | ALTITUDE | 27.9% | -0.5 | 1350 | 253 | 135 |
Slope aspect | ° | EXPOSITION | 33.9% | 0 | 360 | 158 | 180 |
Slope inclination | ° | INCLINATIO | 29.4% | 0 | 90 | 13 | 5 |
Microtopography | cm | MICROTOP | 1.9% | 1 | 30 | 5 | 4 |
Mean soil depth | cm | SOILDEPTH | 15.3% | 0 | 60 | 13 | 8.5 |
pH (H20) | - | PH_H20 | 26.2% | 1.70 | 8.50 | 5.21 | 5.40 |
pH (KCl) | - | PH_KCL | 8.9% | 2.70 | 7.70 | 5.88 | 6.60 |
Cation exchange capacity | meq/100 g | CEC | 1.8% | 1.2 | 99 | 37 | 36.5 |
Base saturation | % | BASE_SAT | 1.8% | 67.15 | 100 | 99 | 100 |
Soil organic matter | mass % | ORG_MAT | 10.4% | 0 | 78.7 | 14 | 12.2 |
CaCO3 content | mass % | LIME_PERC | 0.5% | 0.4 | 80 | 19 | 12.3 |
With the current NBGVD update, the data coverage of grasslands s.l. in the Nordic and Baltic regions has significantly improved in EVA and sPlot, thus facilitating regional, continental, and global analyses of non-forest vegetation. Aside from coming from an underrepresented region, the data in NBGVD are particularly useful for their good quality regarding the treatment of non-vascular plants (currently in more than 80% of all plots and thus high above the EVA average) and the careful curation of environmental header data. However, plot sizes could be a challenge when analysing data from the Nordic-Baltic region together with data from the rest of Europe, as the median plot sizes used in most of the NBGVD countries (4 m2 or even 1 m2) are well below the prevailing practice in most other European countries (
Even with the release of this NBGVD update, the data coverage in the region is still poorer than in many other parts of Europe. Thus, we aim at expanding NBGVD further through the inclusion of additional data which could stem from the digitisation of older published sources from the past or from recent data (published and unpublished) in digital format from current and new consortium members. Promising avenues to retrieve further historical sources are searching for the sources underlying the few synthetic vegetation overviews of the region (e.g.
Decision tree (grey) on how to contribute grassland plots s.l. from the Nordic-Baltic region to national and international vegetation-plot databases to achieve optimal benefit for data contributors and for science. The black lines indicate the flow of data to databases of higher aggregation levels.
Since NBGVD has no funding, we rely on voluntary work both for digitising and georeferencing plots and for further improvement of the quality of already included plots (e.g. to increase the georeferencing precision of plots provided in the past). We also would like to adjust the taxonomic backbone to the current European standards of vascular plants, bryophytes and lichens to allow the most effective use of the data. Here, the “Euro+Med augmented” standard from
We anticipate that having more high-quality plot data from the Nordic-Baltic region will not only improve the validity of future macroecological and global-change studies for this region, but be particularly beneficial for the development of data-based broad-scale vegetation classification systems, of which there are only a few for the open habitats of the region so far, namely for the vegetation of fens (
The database described here is collective property with semi-restricted access. Data can be requested from the last author following the rules defined in the NBGVD Bylaws (Suppl. material
JD and ŁK coordinate the NBGVD Consortium as Custodian and Deputy Custodian, respectively. NS and ŁK currently manage NBGVD and have added new relevés and improved existing data in recent years. JD, ŁK, NS, and ID planned and wrote the report together, while all other authors contributed data, edited and approved the manuscript.
We acknowledge the data contributions by Martin Diekmann, Christian Dolnik, Anna Maria Fosaa (deceased), Thomas Gregor, Antti Hovi (contact lost), Nele Ingerpuu, Barbara Juskiewicz-Swaczyna, Brigitta Laime, Swantje Löbel, Meelis Pärtel, Solvita Rūsiņa, Wojciech Stachnowicz, Annett Thiele, Germund Tyler (deceased), and Sergej Znamenskiy. We thank Stephan Hennekens and Ilona Knollová for their help with data handling and the improvement of data consistency. We thank Florian Jansen and two anonymous reviewers for careful comments on a former version of the manuscript and Hallie Seiler for linguistic editing.
List of all data sources currently contained in NBGVD (*.pdf)
Additional descriptive statistics of the current content of NBGVD (*.pdf)