№ 17-117112040040-3 «Assessment of modern biodiversity and forecast of its change for the ecosystems of the Volga River Basin in the conditions of their natural and anthropogenic transformation»

№ 18-118021490111-5 «Biological diversity of natural and cultural flora: fundamental and applied research and conservation issues»

Stepan Senator, Alyona Tretyakova, Dmitry Vorontsov

The Middle Volga Region is located in the South-East of the European part of Russia. From the aspect of Regional Administration, it is considered as Samara and Ulyanovsk Oblasts of the Russian Federation (Fig. 1).

Figure 1.  

Alien plant species occurrences points (black dots) and coordinate uncertainty zones (red semi-transparent circles) in the study of the Middle Volga Region.

The first step of the study was to create a checklist of alien plant species found in the Middle Volga Region (Senator and Vasjukov 2019). The conceptual basis of the study is the adoption of the idea of the invasive species as an alien plant naturalising into the natural and semi-natural plant communities (Richardson et al. 2010a, Baranova et al. 2018). Hence, all other alien plant species are either recognised as potentially invasive (established and successfully propagating in places where they are introduced, but not spreading into natural and semi-natural plant communities) or non-naturalised.

The dataset is based on Samara and Ulyanovsk Oblasts’ published data on the flora, which are confirmed through stored samples in Herbaria of the Lomonosov Moscow State University (MW), V.L. Komarov Botanical Institute of the Russian Academy of Sciences (LE), Institute of Ecology of the Volga River Basin of the Russian Academy of Sciences (PVB), Ulyanovsk State Pedagogical University named after I.N. Ulyanov (UPSU), Mordovian State University (GMU), Samara State University (SMR) and Moscow Pedagogical State University (MOSP). Additional field research materials, conducted by specialists from the Institute of Ecology of the Volga River Basin of the Russian Academy of Sciences, were taken into account. The listed data are stored in the Salix system of information and analytics, developed in the Institute of Ecology of the Volga River Basin of the Russian Academy of Sciences (Senator et al. 2018).

The earliest data included, regarding the growth of alien plant species in the territory of the indicated region, dates from 1851 to 2019 as the most recent.

This work was supported by the Competitiveness of the Ural Federal University (Russian Federation Government Regulation no. 211, contract no. 02. A03.21.0006).

The presented dataset is based on the published synopsis of alien plants species of the Middle Volga Region (Senator and Vasjukov 2019) and materials stored in the Salix system of information and analytics (Senator et al. 2018). The dataset does not include alien vascular plant species that have presently disappeared from the territory of the Region, likewise species that are native in one part of the study Region, while in another they are found exclusively in disturbed habitats. The terms "introduced species" and "invasive species" are used in accordance with Richardson et al. (2010b) and the system of terms used in Russian-language scientific literature (Baranova et al. 2018).

In 2017, the Salix database was created in order to store floristic information for the Middle Volga Region. The database contains records of all plant species growing in the area of the study. Each entry contains a link to a literary source or a herbarium specimen confirming the findings. The publication of the synopsis of alien plant species in the Middle Volga Region (Senator and Vasjukov 2019) made it possible to highlight and identify the alien plant species. The information about the collectors of herbarium specimens is presented in Table 1.

There are 1472 occurrences in the dataset with coordinate uncertainty of 100 km. This is due to the fact that, in the literary sources of the late 19th and early 20th centuries, there is no exact geolocation. Instead, it is specified, for example, "Western part of Buguruslansky Uyezd" or "neighbourhood of Sergievsk". This collection could be made within a radius of 100 km or more from a settlement. At the same time, such data are of interest from the point of view of identifying the dynamics of the appearance of alien species in the study area.

During the development process of the dataset, the records obtained from primary sources were examined by the first author, as some names of the species did not correspond to the modern nomenclature. The herbarium samples were collected and identified by scientists from the Institute of Ecology of the Volga River Basin of the Russian Academy of Sciences and are stored in the PVB herbarium. The accuracy of the determination of some samples was confirmed by taxonomists from the Lomonosov Moscow State University (MW) and V.L. Komarov Botanical Institute of the Russian Academy of Sciences (LE). For the purposes of publishing the dataset in the GBIF network, the records have been adjusted to match the Darwin Core specifications (Wieczorek et al. 2012).

1. The initial data for this standardised dataset are the information stored in the Salix system of information and analytics, available at https://саликс.рф/Salix/. This information is updated regularly.

2. The Salix system of information and analytics enables us to generate a report in an Excel table form with the necessary dataset. For the purposes of the report, the fields «Species name», «Family», «Administrative Oblast», «District», «Location», «Geographical coordinates», unique identifiers for each taxon and bibliographic references were generated, containing the necessary information regarding the findings. In cases of an absence of a reference, a herbarium sample collector is specified.

3. The scientific names of plants were adjusted in accordance with the GBIF Taxonomic Backbone.

The dataset fields’ names were chosen according to Darwin Core (Wieczorek et al., 2012) and include the following: "scientificName", "taxonRank", "kingdom", "phylum", "class", "family", "genus", "specificEpithet", "infraspecificEpithet", "stateProvince", "municipality", "locality", "decimalLatitude", "decimalLongitude", "coordinateUncertaintyInMetres", "georeferencedBy", "establishmentMeans", "year", "recordedBy", "identifiedBy", "сollectionCode", "geodeticDatum", "basisOfRecord", "countryCode", "country", "occurrenceID", "institutionCode", "language", "associatedReferences".

The Middle Volga Region is a region located in the South-East of the European part of Russia. In botanical-geographical terms, it is located on the border of the European broad-leaved forest area and the Eurasian steppe area. The area of the region is 99,000 km²; the population density is 48.6 per km². From the aspect of Regional Administration, it is considered as Samara and Ulyanovsk Oblasts of the Russian Federation. The coordinates of the northernmost points are 54.887903 N, 49.289177 E, the southernmost points are 51.774088 N, 50.766883 E, the Western points are 53.988244 N, 45.797979 E and the Eastern points are 54.340690 N, 52.566412 E.

The climatic conditions of the Middle Volga Region are formed under the influence of the drifting western Atlantic Ocean air masses and the Siberian anticyclone macrocirculations. The climate is temperate-continental, with peculiar seasonal circulation, characterised by sharp temperature contrasts between cold and warm seasons, a rapid transition from cold winter to hot summer, moisture deficiency, high evaporation rate and abundance of sunlight. The continentality of the climate increases from west to east. The average January temperature is -11 – -13.5°С, in July – +19°С – +21.0°С. The frost-free period lasts 118–157 days. On the territory of the Region, there is a zonal decrease in annual precipitation from north to south from 540 to 370 mm. The largest part of the area of study is located in the forest-steppe zone, characterised by the presence of typical chernozem soil, an alternation of broad-leaved forests and a rich variety of steppe grasslands. The extreme south point of the territory is occupied by a steppe zone with forb-fescue-feather grass steppes on ordinary and southern chernozem soils.

The largest number of the records was made in the Ulyanovsk Oblast (4052 records or 52%), the smallest in the Samara Oblast (3730 records or 48%).

51.774 and 54.888 Latitude; 45.798 and 52.566 Longitude.

The dataset includes records of expansion on alien plant species in two groups (Pinophyta and Magnoliophyta), 67 families, 247 genera and 413 species (Senator 2020). The majority of the records is occupied by the Magnoliophyta group. The highest number of the records refer to the Dicotyledones (90%), followed by the Monocotyledones (9.7%). The Pinophyta group is represented by a single family of Pinaceae, one genus and one species Larix sibirica (0.3% of records).

The Asteraceae, Poaceae, Brassicaceae, Rosaceae, Fabaceae, Amaranthaceae, Lamiaceae, Solanaceae, Caryophyllaceae and Apiaceae families have a wide range of multi-species and hold the maximum number of records, totalling 255 species that comprise 67% of the records (Table 2). These families are characteristic of European floras’ top spectrum (Lambdon et al. 2008).

A total of 18 families contain a small number of records (less than 10). In this case, the families Cleomaceae, Commelinaceae, Linaceae and Verbenaceae are represented by only one species and one occurrence.

The obtained data provided the proper grounds for identifying the most common alien plant species in the Middle Volga Region. Amongst them are Erigeron canadensis L., Acer negundo L., Tripleurospermum inodorum (L.) Sch.Bip., Lactuca serriola L., Lactuca tatarica (L.) C.A.Mey. etc. (Fig. 2)

Figure 2.  

The species with the largest number of occurrences (species with more than 900 records are shown).

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