Arachnologische Mitteilungen 58

94 T. Hamřík & O. Košulič study suggests that open and barren surfaces are strong deter- minants for this species of spider. Talavera aperta (Fig. 4 j) This species occurs from Europe to Central Asia and is con- sidered a rare European species (Grbić et al. 2015, Nentwig et al. 2019). In Europe, the species was recorded in Serbia, Romania, Ukraine, Russia (Central European), Hungary, Slovakia, Austria, Czech Republic, Poland, Germany, Nether- lands, Belgium, Switzerland, France and Italy (Nentwig et al. 2019).This xerothermic epigeic spider lives in various habitats like oak forest, vineyards and dry forest edges from different parts and altitudes of the eastern part of the Czech Republic (Buchar & Růžička 2002, Bryja et al. 2005). Location: At Site 1, only one individual was collected by sweeping of the sparse vegetation Suggestions for conservation managements The results show that Sites 1 and 2 are the most valuable parts of the study area. These parts are typical for their south or south-easterly orientation and sparse vegetation with scat­ tered small rocks and barren surfaces. A high abundance of the threatened ground-dwelling spiders Alopecosa striatipes and Thanatus arenarius inhabiting open xeric habitats confirm the high value of these sites.The high abundance of these very rare species at Site 2 is likely due to sheep grazing that took place before 2005 and subsequent mowing with the removal of the mown materials. The recent grazing and mowing led to the reduction of plant biomass, which provided a suitable habitat (initial stages of succession) for xerothermic species such as Alopecosa striatipes , Thanatus arenarius , Zelotes aeneus, Zelotes electus , etc. However, part of Sites 1 and 2 is threatened by overgrowth and homogenization caused by the expansion of competitive plant species like Calamagrostis epigejos and Arrhenatherum elatius . This study suggests performing short- term extensive sheep grazing supplemented by mowing in order to reduce only the ungrazed areas with Calamagrostis epigejos (Konvička et al. 2005, Jongepierová et al. 2018). Bur- ning is inappropriate because it supports the spread of expan- sive Calamagrostis epigejos (Házi et al. 2011, Deák et al. 2014). Furthermore, the sites are surrounded by a bush of Prunus spinosa and Rosa canina , which reduce the size of xeric, steppe patches, hence reduction of these shrubs is strongly recom- mended. In contrast, rare and endangered spiders including xero- thermic species were discovered in smaller numbers at Site 3. However, there was a higher occurrence of Alopecosa trabalis and Agroeca cuprea , which are more common in forest-steppes or forest edges than in xerothermic open habitats. A threat to the rocky south-east exposed slope of Site 3 is the overgrowth of expansive shrubs and the accumulation of biomass from leaves, which can strongly change microhabitat conditions (Ausden 2007). In the lower part of the site, there are areas with uniform mesophilic vegetation that are slowly expan- ding to the upper parts with xerothermic vegetation. In parti- cular, this study proposes the reduction of bushes in the lower part of the slope, thus creating a larger area for xerothermic species. Certainly, regular management in the form of mosaic mowing or grazing is requested. It is necessary to leave some older shrubs such as Crataegus monogyna that provide suita- ble habitats for species like Synema globosum , Trichoncus affi- nis, Cheiracanthium oncognathum and more species preferring shadier habitats. Historically, this study acknowledges that grazing was only conducted at small scales, using a limited amount of live- stock. This management approach is beneficial to the overall biodiversity of arthropods. Large scale overgrazing, on the other hand, usually has negative impacts on many organisms (Milchunas et al. 1998, Ausden 2007). Therefore, this study suggests the continuation of grazing which should be carried out in a manner that does not allow the entire area of the re- serve to be grazed. Small non-grazed fences should be main- tained within the grazed areas. These places serve as refuges for invertebrates for whom grazing is not suitable (Konvička et al. 2005). Additionally, prescribed burning in the early spring is suggested in small scales around selected places of the protected area (including all study sites); this can replace mowing. According to Niwa & Peck (2002), this manage- ment can reduce the biomass accumulation that is usually caused by homogeneous mowing (e.g., Noordijk et al. 2010). Burning, together with small-scale grazing and mowing, can enhance the diversity of various habitats, which in turn can improve overall biodiversity (Ausden 2007). In this context, it is also appropriate to leave some small-scale unmanaged parts in all of the sites of the protected area to create a mosaic of habitats in different stages of succession as this will provide biotopes for a wide spectrum of arthropods that may not all profit from regular disturbances such as Agroeca cuprea living in detritus among vegetation (Batáry et al. 2010). In conclusion, diversification of management must be car- ried out in parts of the area throughout the year. Accordingly, each organism has the opportunity to find suitable habitats; if one of the interventions is poorly undertaken, other methods will compensate for its negative effects (Di Giulio et al. 2001, Ausden 2007, Bucher et al. 2016). Acknowledgements The authors would like to thank Petr Dolejš (National Museum in Prague) for the determination and revision of spider taxa that were difficult to identify. We likewise extend our warm appreciation to Denise Paulina V. Doble and Nicole H. Cernohorsky for the English proofreading; to Anna Foltýnová, Josef Hamřík,Lukáš Dolíhal,Marie Hamříková,Ondřej Dohnal,Pavla Vymazalová,ŠárkaMašová,Vikto- rie Košuličová,Vojtěch Václavík, Zdeněk Sucharda and the members of ZO ČSOP Eresus and ZO ČSOP Náměšťské rybníky for their assistance during fieldwork. Additionally, we are grateful to the re- viewers and editor (Theo Blick) for their comments that significantly improved the manuscript. This research was performed within the Zoological inventory of spiders in the Pláně Nature Monument and was financially supported by the South Moravian Region.The study was financially supported by the Specific University Research Fund of the Faculty of Forestry and Wood Technology,Mendel University in Brno (LDF_PSV_2017004/2017). References Ausden M 2007 Habitat management for conservation: A handbook of techniques. Oxford University Press, New York. 424 pp. – doi: 10.1093/acprof:oso/9780198568728.001.0001 BAS (British Arachnological Society) 2019 Spider and harvestman recording scheme website. – In t ernet: http://srs.britishspiders. org.uk (3. Jun. 2019) Batáry P, Baldi A, Sarospataki M, Kohler F, Verhulst J, Knop E, Herzog F & Kleijn D 2010 Effect of conservation management on bees and insect-pollinated grassland plant communities in three