Spiders (Araneae) of the northeast of the Luhansk Oblast (Ukraine)

Abstract Background The dataset contains records of spiders collected in the northeast of Luhansk Oblast in the periods 1982-1989, 2009-2011 and 2021. It aimed at the inventory of spider fauna of the Striltsivskyi Steppe Nature Reserve and species distribution in the main grassland and forest habitats of the region. The research was also concerned with the impact of conservation management ‒ hay mowing or strict protection and man-induced steppe fire on spider communities. New information The dataset includes records from seven geographical localities in the northeast of Luhansk Oblast with 1,955 occurrences of 6662 individuals. For the first time, it provides detailed information about spider species composition, phenology and habitat distiribution within the study area, including two conservation areas and the primary material on the studies on the impact of hay making and steppe fire on spider communities. All the records of 246 spider species with georeferencing were published in GBIF.


Introduction
The lands of the Starobilsk Raion of the Luhansk Region, like the whole steppe zone of Ukraine, are highly transformed by human economic activity.The ploughing campaign was launched there in the 1930s and resulted in nearly all natural steppes being converted into agricultural fields.Now zonal forb-fescue-feather grass steppes on the flat interfluves are extant only in the Striltsivskyi Steppe Nature Reserve.Nevertheless, due to the rolling relief and the horse breeding developed in the late 17 -early 20 century, the Starobilsk Steppes are less ploughed than the southern Ukrainian steppes (Borovyk 2018).Remains of the virgin steppes, intensively grazed up to the 1990s, have been preserved on the gully slopes and bottoms.Natural arboreal and shrub vegetation forms narrow strips along the river banks and small patchy forests and shrub thickets in the gullies.
The vegetation of the Starobilsk steppes was investigated first in [1926][1927] (Lavrenko and Dokhman 1933).Subsequently, it has been constantly monitored since the establishment of the Striltsivskyi Steppe protected area, now a department of the Luhansk Nature Reserve (Tkachenko 2009).In contrast, invertebrates were studied at irregular intervals, only some groups of beetles (Glotov 2021) and mites (Yaroshenko and Schtirts 2008) having been sampled thoroughly and analysed.Since various groups of organisms respond differently to the impact of natural and anthropogenic factors, comprehensive multitaxon studies are of critical importance for understanding changes in local biota, assessment of conservation effects (Margules andPressey 2000, Braby andWilliams 2016) and development of optimal management plans of protected areas and ecologically friendly farming (Batáry et al. 2012).
Being abundant and diverse predators, spiders play an important role in trophic webs (Wise 1993, Mallis andHurd 2005).They have various ecological traits and inhabit all vegetation layers in nearly all terrestrial habitats.Spiders' diversity and ecological role make them a suitable model group for bioindication (Marc et al. 1999, Zografou et al. 2017, Cabrero-Sañudo et al. 2022).
Arachnological research in the northeast of the Luhansk Oblast was launched by the first author (NP) in the 1980s.Before that, only one locality in the southeast of the Oblast (Provllia Village, at that time Don Host Area) was investigated and a list of 55 species was published (Greze 1909). In 1982-1989, the studies aimed at the inventory of spider fauna of the Striltsivskyi Steppe department of the Luhansk Nature Reserve and clarifying the impact of mowing management on spider assemblages (Polchaninova 1990a, Polchaninova 1995, Polchaninova 2012a).Hereinafter, E. Prokopenko (Donetsk National University, Ukraine) continued spider inventory (Prokopenko 2001) and the results were summarised in a survey of the state of knowledge of the spider fauna of Ukrainian steppe th th reserves (Polchaninova and Prokopenko 2007) and in the spider checklist of the Luhansk Nature Reserve (Polchaninova and Prokopenko 2011).In total, 334 spider species of 28 families were recorded from the Reserve, with 190 species registered in the Striltsivskyi Steppe.
After the devastating fire of 2008 that destroyed all vegetation in the Reserve and its vicinity, arachnological studies were focused on the effect of large-scale steppe fires on spider communities (Polchaninova 2013a, Polchaninova 2013b, Polchaninova 2015, Zografou et al. 2017).In addition, the study localities were expanded to collect spiders in other habitats typical of the region (chalk grasslands, clayey slopes, forests in the gullies, pine plantations etc.).The obtained data on spider inventory and species habitat preferences were included in the Catalogue of Spiders of Left-Bank Ukraine (Polchaninova andProkopenko 2013, Polchaninova andProkopenko 2017) and used for the comparison of the spider faunas of various steppe reserves (Polchaninova 1990b, Polchaninova 2012b, Prokopenko and Polchaninova 2017, Polchaninova 2021).At present, 223 spider species are known from the Striltsivskyi Steppe Reserve; other 23 species listed in the catalogue were found outside its territory.This is more than half of the species recorded from the Luhansk Oblast (402 species) (Polchaninova and Prokopenko 2019).Twelve recorded species are rare in Ukraine and 16 species are rare or patchily distributed in the study area.They can serve as bioindicators to determine areas of conservation concern.

General description
Purpose: The presented data will contribute to the understanding of the spider fauna of eastern Ukraine, assessment of the effectiveness of conservation management in protected areas and identification of the sites of conservation concern.Moreover, the research on spider post-fire recovery will serve as a basis for evaluating the aftermath of hostilities that arose due to Russia's invasion of Ukraine.Sampling description: Spiders were collected by standard collecting methods: sweep netting, pitfall trapping, quadrat sampling and by hand.Plastic cups of 6.5 cm diameter were used as traps and 4% formalin was used for preservation.At each study plot, we set a line of 10 traps at a 10 m distance.The traps were exposed for 3-5 days once per month in the study period 1982-1989. In 2009-2011, the traps were checked approximately once a month from early May to early July and from September to October.Sweep netting was conducted with a 30-cm diameter entomological net, three to five samples of 50 sweeps per plot/month.The quadrat sampling was performed by collecting spiders by hand from 25 x 25 cm plots on the ground and in the litter and thatch.The number of individuals given in the dataset can be normalised to 100 trap-days, other sampling efforts are not specified.

Project description
The hand collecting was only qualitative.

Quality control:
The collected spiders were preserved in 70% ethanol and identified by the first author (NP).Taxonomy nomenclature follows the World Spider Catalog (http:// wsc.nmbe.ch,accessed 10.11.2022).The material is deposited in N. Polchaninova's private collection (Kharkiv, Ukraine).

1.
Step description: Field expeditions to the study sites.

2.
Establishing a line of ten traps at a distance of 10 m at each study plot.

3.
Regular checking of the traps.

4.
Sweep netting conducted in the same habitats, three to five samples of 25 double sweeps per plot; hand collecting.

5.
Georeferencing with the help of GPS-navigator.

6.
Species identification in the laboratory.

7.
Organising of a dataset according to Darwin Core standards.

Geographic coverage
Description: All collecting localities are limited to the Starobilsk Raion of the Luhansk Oblast.Two localities lie in the north of the region, one in the south and the others in the northeast.The area in question is located on the southern spurs of the Central Russian Upland.The climate is moderate continental.In terms of physical-geographical division, the area belongs to the Starobilsk slope-and-upland oblast of the Transdonets-Don krai, of the Northern steppe subzone of the Steppe zone (Marynych et al. 2003).In terms of geobotanical zoning, it refers to the Siverskyi Donets okrug of the forb-bunchgrass steppes, bairak oak forests and vegetation of the chalk outcrops (tomillares) of the Middle Don subprovince of the Pontic steppe province of the Eurasian steppe region (Didukh and Shelyag-Sosonko 2003).

Taxonomic coverage
Description: The dataset includes records of 6662 spiders belonging to 246 species of 137 genera and 27 families (Table 2).Most individuals were identified at the species level.Spiders (Araneae) of the northeast of the Luhansk Oblast (Ukraine) year

.
We also marked with the letter B the sampling localities in Striltsivskyi Steppe burnt in August 2008.In the Table of species habitat distribution (Table2), we combined in one column shelter forest belts+forest edges as ecotone habitats and pine plantations+bairak forests as the forest ones.

Table 2 .
The list of spider species, their habitat distribution and the number of collected individuals in the northeast of the Luhansk Oblast: 1forb-fescue-feather grass steppe on the flat interfluves and Spiders (Araneae) of the northeast of the Luhansk Oblast (Ukraine) Darwin Core acceptedNameUsage http://rs.tdwg.org/dwc/terms/acceptedNameUsage;thefull name of the currently valid taxon of registered species from Araneae order.kingdom http://rs.tdwg.org/dwc/terms/kingdom; the full scientific name of the kingdom in which the taxon is classified.phylum http://rs.tdwg.org/dwc/terms/phylum; the full scientific name of the phylum or division in which the taxon is classified.class http://rs.tdwg.org/dwc/terms/class;thefull scientific name of the class in which the taxon is classified.order http://rs.tdwg.org/dwc/terms/order; the full scientific name of the order in which the taxon is classified.family http://rs.tdwg.org/dwc/terms/family; the full scientific name of the family in which the taxon is classified.genus http://rs.tdwg.org/dwc/terms/genus;thefull scientific name of the genus in which the taxon is classified.specificEpithet http://rs.tdwg.org/dwc/terms/specificEpithet; the name of the first or species epithet of the scientificName.taxonRank http://rs.tdwg.org/dwc/terms/taxonRank; the taxonomic rank of the most specific name in the scientificName.decimalLatitude http://rs.tdwg.org/dwc/terms/decimalLatitude;geographic latitude in decimal /rs.tdwg.org/dwc/terms/geodeticDatum;spatialreference system upon which the geographic coordinates are given (WGS84).coordinateUncertaintyInMetres http://rs.tdwg.org/dwc/terms/coordinateUncertaintyInMeters; the horizontal distance (in metres) from the given decimalLatitude and decimalLongitude describing the smallest circle containing the whole of the location.recordedBy http://rs.tdwg.org/dwc/iri/recordedBy;authorship of the record.georeferencedBy http://rs.tdwg.org/dwc/terms/georeferencedBy;theperson, who provided the records with correct coordinates.identifiedBy http://rs.tdwg.org/dwc/iri/identifiedBy;authorship of the taxon identification.language http://purl.org/dc/terms/language;the language of the resource.verbatimEventDate http://rs.tdwg.org/dwc/terms/verbatimEventDate;theoriginal form or even date record in the author's notes from the fieldwork.