Biodiversity Data Journal 9: e68046 doi: 10.3897/BDJ.9.e68046 Data Paper Flora of Vladimir Oblast, Russia: an updated grid dataset (1867–2020) Alexey P. Seregin ‡ ‡ Lomonosov Moscow State University, Moscow, Russia Corresponding author: Alexey P. Seregin ([email protected]) Academic editor: Ivan Chadin Received: 29 Apr 2021 | Accepted: 24 May 2021 | Published: 28 May 2021 Citation: Seregin AP (2021) Flora of Vladimir Oblast, Russia: an updated grid dataset (1867–2020). Biodiversity Data Journal 9: e68046. https://doi.org/10.3897/BDJ.9.e68046 Abstract Background The dataset covers wild tracheophytes (native species, naturalised aliens and casuals) of Vladimir Oblast, Russia. It includes only one occurrence per species per grid square, thereby recently confirmed earlier records are not duplicated. Georeferences are based on the WGS84 grid scheme with 342 squares with areas ranging from 94.7 km2 in the northernmost part to 98.2 km2 on the southern boundary (5′ lat. × 10′ long.). Each occurrence is linked to the corresponding grid square centroid, therefore actual coordinates, habitat details and voucher information are unavailable. In late 2011, the earlier version of the dataset was used for the production of grid maps in the standard "Flora of Vladimir Oblast: checklist and atlas". Additional records, obtained during field excursions of 2012 and 2013, were fully included in the "Flora of Vladimir Oblast: grid data analysis". The stable version of the dataset with 123,054 grid records (as of 1867–2013) was published in GBIF in 2017. New information Data obtained in the field during 2014–2020, as well as those extracted from recently published sources, were digitised, structured and finally published in GBIF in April 2021. © Seregin A. 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. 2 Seregin A The last update added 7,000 new grid records. Currently, "Flora of Vladimir Oblast, Russia: an updated grid dataset (1867–2020)" contains 130,054 unique occurrences of 1,465 vascular plant taxa (species, hybrids, species aggregates) from Vladimir Oblast and tiny parts of the adjacent areas. The average number of grid records has grown over the seven years from 363 to 380 species. The grid occurrences are largely based on the field studies by the author, performed during 1999–2020 (121,737 records), as well as on data extracted from the relevant literature, unpublished sources, herbarium collections and citizen science projects (8,317 records). The taxonomic backbone of the occurrence grid dataset follows the accompanying checklist dataset to ensure correct cross-linking of the names. As of April 2021, the dataset on the Vladimir Oblast flora represents the fourth largest dataset on vascular plants of Russia published in GBIF. Keywords vascular plants, dataset, flora, Vladimir Oblast, Russia, occurrence Introduction Since 1999, the author has been working on the grid mapping of the Vladimir Oblast flora. The region covers an area of 29,074 km2 . The oblast was divided into 342 grid squares measuring 5′ lat. x 10′ long. or ca. 9.2 x 10.4 km. Thus, the area of the grid cells slightly increases southwards from 94.7 to 98.2 km2 (Fig. 1). Cyrillic letters were used to designate 21 rows from north to south, while numbers were used to indicate the squares within the rows from west to east. The northern border of the northernmost row А follows 56°50′N, while the southern border of the southernmost row Х follows 55°05′N, the western border of the squares Г1 and Д0 follows 38°10′E, while the eastern border of the square З28 follows 43°00′E. The grid is available as a supplementary *.kml file (Suppl. material 1) with a copy on Zenodo (https://doi.org/10.5281/zenodo.4724913). The grid is visualised on Google Maps at https://maps.google.com/maps/ms?msid=200284766630468455543.00 0462414ec0fd70a9c6f&msa=0 Every year, data obtained by the author in the field were imported into the distribution database on the Vladimir Oblast flora (MS Excel spreadsheet). The earlier version of the database supplemented by all available records from the literature and herbarium collections was used to produce maps for the standard "Flora of Vladimir Oblast: checklist and atlas" (Seregin 2012). At the time of map production for the flora in November 2011, the database contained 118,231 records. In 2012–2013, the author continued the grid mapping of the Vladimir Oblast flora. By the end of 2013, the regional flora included 1,399 species of vascular plants (Seregin 2014). The stable version of the dataset with 123,054 grid records (as of 1867–2013) was published in GBIF in November 2017 (Seregin 2021b). Flora of Vladimir Oblast, Russia: an updated grid dataset (1867–2020) 3 Figure 1. The grid scheme with 342 squares currently used for the floristic surveillance of Vladimir Oblast, Russia (5′ lat. x 10′ long.). There were 335 grid squares in the initial scheme (white squares). Subsequently, Seregin (2012) added Л0 and C0, whereas Seregin (2014) added A0 and Д0. In 2018, three grid squares (Б0, Л25 and М22) were included for the better curation of some small areas of Vladimir Oblast outside the regular grid. The squares added during 2011–2018 are shown here in grey. In line with the call for data papers describing datasets from Russia by GBIF, we completely revised the dataset and made the following improvements and ammendments: 1. Field data obtained by the author during 2014–2020 and new data published recently in various references were fully integrated into the dataset. New field data were obtained by the author during 77 standard one-day grid square surveys, as well as dozens of occasional field excursions focused on specific plant habitats, communities or species. 2. This update added 7,000 new grid records into the dataset, including records of 26 new species. For at least 11,190 grid records, the date of the last record was updated to show current presence of the species. 3. Three new grid squares were added on the fringes of Vladimir Oblast. The average number of grid records increased within seven years from 363 to 380 species (Table 1). 4. The taxonomic backbone of this occurrence dataset follows Seregin (2014), available in GBIF as a checklist dataset (Seregin 2021c) to ensure correct cross- linking of the names. 5. An aggregation of the records by standard grid square surveys was performed using the "eventID" field of the DarwinCore. 4 Seregin A Table 1. The growth of the dataset during 2011–2020. The earlier version of the dataset with 118,231 grid records (as of late 2011) was used for the map production in the standard flora (Seregin 2012). End of the year Number of records Number of grid squares Average number of records per grid square 2011 118,231 337 350.8 2012 120,854 337 358.6 2013 123,049 339 363.0 2014 124,100 339 366.1 2015 126,682 339 373.7 2016 127,245 339 375.4 2017 127,415 339 375.9 2018 128,966 342 377.1 2020 130,073 342 380.3 We amended the dataset on 29 Apr 2021 after a thorough data audit, performed by Dr Robert Mesibov (https://www.datafix.com.au) in line with preparation of the data paper. As of 19 April 2021, the Vladimir Oblast occurrence dataset on the flora makes the seventh largest dataset on biodiversity of Russia published in GBIF (Table 2) and the fourth largest for vascular plants after Ueda (2021), Seregin (2021a) and Artemov and Egorova (2021). This is the only complete grid dataset for the first-level administrative divisions across Russia, although there are at least three GBIF-mediated datasets based on grid surveys of specific second-level administrative units in Tver, Saratov and Yaroslavl Oblasts of European Russia (Abramova and Volkova 2018, Frontova 2019, Pashkina 2019). Table 2. Top-10 datasets by the number of records on the biodiversity of Russia published in GBIF (as of 19 April 2021). Rank Dataset Reference Number of records 1 iNaturalist Research-grade Observations Ueda (2021) 1,247,040 2 Moscow University Herbarium (MW) Seregin (2021a) 659,565 3 RU-BIRDS.RU, Birds observations database from Russia Ukolov et al. (2019) 433,635 and neighbouring regions 4 EOD - eBird Observation Dataset Levatich and Ligocki (2020) 282,227 Flora of Vladimir Oblast, Russia: an updated grid dataset (1867–2020) 5 Rank Dataset Reference Number of records 5 Geographically-tagged INSDC sequences European Nucleotide Archive 195,451 (EMBL-EBI) (2019) 6 Locations of plants on dot distribution maps in the Flora of Artemov and Egorova (2021) 169,854 Siberia (Flora Sibiraea, 1987–1997) 7 Flora of Vladimir Oblast, Russia: an updated grid dataset Seregin (2021b) 130,054 (1867-2020) 8 Finnish Floristic Database (Finnish Museum of Natural Lampinen and Laiho (2021) 106,396 History Collections) 9 Birds of Northern Eurasia Karyakin et al. (2020) 86,992 10 Chronicle of Nature - Phenology of Plants of Zhiguli Kiseleva (2021) 86,524 Nature Reserve Amongst the datasets published by the Russian institutions, this occurrence dataset on the flora makes the fourth largest dataset available in GBIF (Table 3*1) and the third largest dataset for vascular plant diversity after Seregin (2021a) and Artemov and Egorova (2021). Table 3. Top-10 datasets by the number of records published in GBIF by the Russian institutions (as of 19 April 2021). Rank Dataset Reference Number of records 1 Moscow University Herbarium (MW) Seregin (2021a) 1,025,148 2 RU-BIRDS.RU, Birds observations database from Russia Ukolov et al.