New data on the spider fauna (Araneae) of Navarre, Spain: results from the 7th EDGG Field Workshop

Abstract. Multi-taxon investigations are of great importance in biodiversity research. We sampled spiders during the 7th EDGG Field Workshop aimed at studying dry grassland diversity in Navarre, Spain. A total of 99 spider species from 15 families were recorded from 14 localities. Of these, 47 species were new to Navarre. To date, the list of spiders of Navarre accounts for 322 species. During this first dry grassland-specific study of spiders in Spain, 78 species were recorded for the first time in this type of habitat in Navarre, and for 69 species it is a newly recorded habitat in the Iberian Peninsula. The grasslands growing in the submediterranean humid and supramediterranean upper dry territories, belonging to Festuco-Brometea and Festuco-Ononidetea phytosociological classes, were the richest in terms of inhabiting spiders (26 and 23 species respectively) while the communities of mesomediterranean semi-arid area (Lygeo-Stipetea and Salicornietea fruticosae classes) were the poorest (four species each).

The spider fauna of the Iberian Peninsula and of the Balearic Islands is relatively well catalogued. Pedro Cardoso presented a preliminary checklist of Portuguese spiders in 2000 (Cardoso 2000). In 2004, Eduardo Morano published a list of recorded species of Iberian spiders together with a bibliography of available publications on that topic (Morano 2004). This review provided the number of species, Iberian endemics, collecting localities and references for each administrative region of Spain and Portugal. It also revealed the best and worst studied regions of the Iberian Peninsula, and thus outlined promising areas for future investigations.
The next stage of synthesis was the creation of an electronic catalogue of the Iberian spiders (Morano & Cardoso in Cardoso & Morano 2010). An accompanying paper presented an updated checklist of spiders with respect to the provinces and a comparative analysis of the records, species and endemic species in each family and province (Cardoso & Morano 2010). The third (and latest) version of the Iberian spider catalogue provided maps of collecting localities and exhaustive data on the records of 1382 species in 381 genera and 55 families (Morano et al. 2014). Conducting such a huge job, the catalogue authors concluded that the spider fauna of the Iberian Peninsula is still severely incompletely studied. The territory has been unevenly surveyed, there is a shortage in the data on species habitat distribution, and only some families have a sufficient species list (Cardoso & Morano 2010).
The Eurasian Dry Grassland Group EDGG (Vrahnakis et al. 2013) organizes research expeditions (so-called Field Workshops) since 2009, aimed at sampling standardized, high-quality data on species composition and diversity of grasslands and related communities (Dengler et al. 2016). Data collection initially focused on plant diversity; the 7 th Field Workshop conducted in the region of Navarre in Spain (Biurrun et al. 2014) was the first example to include invertebrate collection, namely spiders, in the sampling protocol. This opened the opportunity to expand information about spiders in the study region and specify their distribution in various types of grasslands.
The Iberian spider catalogue includes 539 spider records in the region of Navarre, which correspond to 231 species in 141 genera and 35 families; the 79 collecting localities are documented in 37 papers (Morano et al. 2014). Spider habitat distribution in Navarre is known only for 13 cave species (see Morano et al. 2014) and for 149 species from oak and beech-oak forests (Castro & Ferrandez 1998, Castro & Alberdi 2002, Castro & Barriuso 2004, Castro 2009, Morano et al., 2014. The current paper presents spider records from the 7 th EDGG Field Workshop, thus providing a major supplement to the list of spiders of Navarre, and reports the first data on spider species composition in the dry grasslands of the study region. tains in the northeast to the Ebro depression in the south (Fig. 1). Three biogeographic units are represented in Navarre: Alpine, Atlantic and Mediterranean. The climate changes from Mediterranean in the south of the study area to temperate in the north, with the temperate sub-Mediterranean type in transitional areas. The ombrotype varies from semiarid to subhumid in the Mediterranean Region and from humid to hyperhumid in the Atlantic and Alpine Regions (Peralta et al. 2013). The natural vegetation is highly diverse, given the marked climatic and biogeographic gradient. Deciduous oak and beech forests prevail in the northern areas and Mediterranean evergreen woodlands and scrubs in the south (Loidi & Báscones 2006, Peralta et al. 2013. Sampling was carried out in a great variety of grasslands, ranging from subalpine grasslands, through mesic meadows, dry grasslands to endorheic basins, belonging to ten associations and six phytosociological classes (Berastegi 2013), most of them being semi-natural, i.e. maintained by human activity.
Subalpine grasslands belong to the class Juncetea trifidi, which groups acidophilous swards of the Pyrenees. Basophilous subalpine and supratemperate grasslands in the high mountains are included in the class Elyno-Seslerietea. At middle elevation, in submediterranean territories, the sampled grasslands belong to the classes Festuco-Brometea and Festuco hystricis-Ononidetea striatae. The former occupies deep baso-neutrophilous soils and the latter, rich in dwarf scrubs, grows in shallow and stony soils. The class Lygeo sparti-Stipetea tenacissimae comprises basophilous xerophitic grasslands from dry and semiarid Mesomediterranean areas. Finally, communities growing in endorheic areas with salty soils are included in the class Salicornietea fruticosae (Mucina et al. 2016).

Data collection
Material was collected on 16-23 June 2014 during the 7 th EDGG Field Workshop in Navarre (Biurrun et al. 2014). Fourteen localities were chosen for the dry grassland survey along the climatic and biogeographic gradient (Fig. 1). Spiders were sampled using a standard procedure of sweep netting and hand collecting. In addition to grasslands, we collected spiders in adjacent habitats, and the species were included in the general list.
Below, the study localities, grouped by biogeographic regions, are listed with the following information: locality, geographical coordinates in WGS84, elevation, date of collection, ombro-and thermotype of climate, and phytosociological class of grassland vegetation. Different vegetation classes studied in the same locality are marked with a letter (a, b).

Spider species list
Adult individuals of spiders were identified using Heimer & Nentwig (1991) and Nentwig et al. (2018). For the identification of some rare or sibling species we used Bosmans & Abrous (1992), Barriento (1994), Kastrygina & Kovblyuk (2016), Spasojevic et al. (2016), Bosmans et al. (2018) and Isaia et al. (2018). The annotated checklist of spiders is arranged alphabetically for families and within families following the nomenclature of the World Spider Catalog (WSC 2018). The list is based on the collected adult individuals; we mention juveniles only if adults were absent from a given locality. The number of the locality is provided with a letter if a species was collected in the grassland vegetation of the above-mentioned type. In other cases, we specify both locality and habitat (edge of a beech forest, under stones, etc.). The total number of collected species in a particular family is given in parenthesis after the family name. Species new to Navarre are indicated with an exclamation mark (!).
The bulk of the collected material is deposited in N. Polchaninova's private collection (Kharkiv, Ukraine). Some specimens have been donated to the Museum of Nature of the V.N. Karazin Kharkiv National University, Ukraine (NMKhNU).
Spider species composition was poorest in Bardenas Reales [1], at the bottom of the mountain pass of Puerto de Urbasa [10], and the Larra-Arlas Mountains [12] (7-8 species only), and the richest in Ihabar [8] (43 species) (Tab. 1). If only the spiders collected in grasslands are considered, the same localities were again the poorest, and Ihabar the richest (26 species) followed by the hills in vicinity of Lorca [3] (23 species). Ihabar is located in the Atlantic biogeographic region while Lorca in the Mediterranean one. In the investigated grasslands, we recorded 51 spider species in the Atlantic region, 36 species in the Mediterranean region, and 18 species in the Alpine region.
Two phytosociological classes, Festuco-Odonidetea and Festuco-Brometea, were the most widespread in the study area. The former hosted 32 spider species and the latter 41 species (Tab. 1).

Discussion
Prior to our study, 275 spider species were known from Navarre, 231 species listed in the Iberian spider catalogue (Morano et al. 2014) and additional 44 species recorded from the oak forest of Orgi (Lizaso) (Castro & Barriuso 2004). We found 99 species from 15 families. Of these, 47 species are new to Navarre including one species described as new to science (Kastrygina et al. 2015). Thus, the total list of spiders has been enlarged to 322 species. By number of species registered, Navarre can now be included in the top six provinces of Spain and Portugal regarding spider species richness: Huesca -430 species, Barcelona -356, Coimbra -321, Madrid -313 and Salamanca -300 species (Morano et al. 2014). Nevertheless, considering a large gradient of altitudinal and climatic conditions, the spider species list of Navarre is certainly far from complete.
In all the study localities, arachnological researches were conducted for the first time. In Bardenas Reales, spiders had been previously collected only in Vedado de Eguaras, an 'oasis' of Pinus halepensis in the semi-arid area (Romano in Morano et al. 2014). There were no previous specific studies on dry grassland spiders in Spain. The records of 78 species are new for this type of habitat in Navarre; for 69 species, it is a newly recorded habitat in the Iberian Peninsula.
The Festuco-Brometea grasslands in the mesotemperate humid climate (Ihabar) and the Festuco-Ononidetea in the submediterranean subhumid climate (Lorca) hosted the richest spider communities (26 and 23 species, respectively). Interestingly, the grasslands of Ihabar were also the richest in terms of plant diversity (Biurrun et al. 2014). The poorest was the vegetation of Lygeo-Stipetea and Salicornietea fruticosae phytosociological classes in the mesomediterranean semiarid climate in Bardenas Reales (four spider species each). A higher abundance of spider species collected in the Atlantic grasslands can be explained by a wide variety of altitudes and habitats (from stony pastures to slopes with dense shrubs and herbs) compared with the studied grasslands in the Mediterranean and Alpine regions. Spider communities of the Iberian dry grasslands need further investigation for more detailed analysis.