Arachnologische Mitteilungen 58

86 T. Hamřík & O. Košulič brown forest soils (Matuška 2016). In general, the Pláně NM lies in a distinctly colder region of South Moravia in the phy- togeographical region of Mesophyticum along the border of the South Moravian and Highlands region (Skalický 1988, Slavík 1988, Buchar & Růžička 2002). The average annual temperature is 8 °C and the average annual rainfall is 579 mm (Matuška 2016). The average altitude is 450 m. Its surround- ing landscape is heterogeneous with various habitat types like hedgerows with Prunus spinosa , mixed forests and cereal fields. The study area was traditionally maintained by sheep gra- zing, but there has been no management from 2009 to 2016 (Matuška 2016). Unfortunately, the Pláně NM is currently overgrowing with pine forest, invasive Robinia pseudoacacia , pioneer shrub species and expansive Calamagrostis epigejos. Sample collection and study sites The spiders were collected in two seasons: from 7. May to 15. Oct. 2017 and from 19. Apr. to 21. Sep. 2018. Pitfall traps and sweeping were used as the collection methods for epigeic and herb-dwelling spiders respectively. Each pitfall trap consisted of a plastic cup (500 ml, diameter 9 cm, depth 15 cm) buried in the ground where its rim is level with the soil surface. Each trap was filled with a 3-4% solution of formaldehyde and de- tergent as a killing and fixative fluid. Sweeping sampling was carried out only during favourable weather conditions, i.e. a minimum of 17 °C and sunshine (period between 10:00 h and 17:30 h). After collecting, the samples were preserved in 70% ethanol. The online application BioLib (2018) was used for the mapping of species occurrence, whereas the distribution data were taken from ČAS (2019). The following design was used to assess the effect of con- servation management methods on spider biodiversity in the study location (Hamřík 2019). Three sites in the study area were selected, wherein each had a total of 16 plots (4 m × 5 m) (Fig. 1).Two pitfall traps were placed in the centre of each plot, making a total of 32 pitfall traps for each site. Sweeping of herb vegetation took place inside each plot (20 sweeps per plot). In this publication, we present only the faunistic results. Site 1 (452-448 m a.s.l.) and Site 2 (442-439 m a.s.l.): These slightly steep slopes are characterized by southerly (Site 1) and south-east orientations (Site 2). They are often rocky and herbaceous vegetation is sparse with Festuca ovina gro- wing on shallow soil. Calamagrostis epigejos and Arrhenathe- rum elatius prevail in nutrient-rich parts. Before 2005, sheep grazing and subsequent mowing with removal of the mown material took place at Site 2. Site 3 (435-421 m a.s.l.): This site is characterized by a very steep slope with a south-easterly orientation. The lower part of the slope is covered with nutrient-rich soil and dense vegetation, represented by Calamagrostis epigejos and Arrhena- therum elatius .The upper part of the slope is rocky with sparse herbaceous vegetation, mainly Festuca ovina . Several trees and shrubs like Prunus spinosa and Crataegus monogyna are present at the site. Species identification and classification Using the identification keys of Heimer & Nentwig (1991) and Nentwig et al. (2019), only adult spiders were used and de- termined down to species level. Every species was categorized according to hunting strategies (Fig. 2): sensing-web weavers, sheet-web weavers, space-web weavers, orb-web weavers, am- bush hunters, other hunters, ground hunters and specialists (Cardoso et al. 2011).The most up-to-date data on nomencla- ture were taken from the World Spider Catalog (WSC 2019) and the arrangement of families is based on the spider phylo- genetic tree of Wheeler et al. (2017). The authors determined almost all species; taxonomically complicated taxa were revised and determined by another specialist (Petr Dolejš, National Museum in Prague). Each species was evaluated according to Buchar & Růžička (2002) and Řezáč et al. (2015) (Tab. 1): 1) occurrence level, 2) habitat preferences, 3) thermo preferences, 4) conservation status. Occurrence level is categorized accor- ding to the abundance based on the estimated number and dis- tribution of grid squares with potential species occurrence (the presence of suitable habitats): very abundant (VA), abundant (A), scarce (S), rare (R), very rare (VR). Another evaluation is based on habitat preferences according to degree of habitat originality: climax preferences (C), seminatural habitats (SN), disturbed (D), artificial (A). Thermo preference is categorized according to occurrence of spider species in phytogeographic districts:Thermophyticum (T), Mesophyticum (M), Oreophy- ticum (O).The last evaluation is the conservation status which is based on the Red List categories: critically endangered (CR), endangered (EN), vulnerable (VU), least concern (LC). The basic values are written in regular font; the markedly preferred values are in bold; and some marginal but non-negligible valu- es are in parentheses (see Tab. 1). Species richness estimation For estimation purposes, if the absolute species number in the 48 samples thoroughly represented alpha diversity of the study area, Jackknife1 resampling with 100 randomizations using the Software EstimateS 9.1 was performed (Colwell 2013). Results and discussion Faunistic overview Overall, 11634 adult spiders belonging to 154 species in 88 genera of 25 families were collected (Tab. 1). Altogether, 133 species from 10532 specimens (91%) were caught by pitfall traps and 49 species from 1102 specimens (9%) were caught Fig. 1: Study area (black square in the map) and sites with rectangles whe- re the pitfall traps were placed and sweeping took place (ESRI 2013)