See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/328613752 Both local and landscape-level factors are important drivers in shaping ground-dwelling spider assemblages of sandy grasslands Article in Biodiversity and Conservation · February 2019 DOI: 10.1007/s10531-018-1654-3 CITATIONS READS 7 209 5 authors, including: Roland Horváth Tibor Magura University of Debrecen University of Debrecen 47 PUBLICATIONS 1,088 CITATIONS 121 PUBLICATIONS 4,417 CITATIONS SEE PROFILE SEE PROFILE Béla Tóthmérész János Eichardt University of Debrecen Hamvas Béla Gimnázium 374 PUBLICATIONS 9,740 CITATIONS 10 PUBLICATIONS 82 CITATIONS SEE PROFILE SEE PROFILE Some of the authors of this publication are also working on these related projects: Predators in the service of the humankind View project Diverse seed mixtures for establishing native cover crop vegetation in vineyards View project All content following this page was uploaded by Roland Horváth on 12 November 2018. The user has requested enhancement of the downloaded file. 1 This is the submitted version (preprint) of the article published in Biodiversity and 2 Conservation (Springer). 3 The published article is available at: https://link.springer.com/article/10.1007%2Fs10531- 4 018-1654-3 5 It is free to read or download on this link: https://rdcu.be/baoD7 6 On request we will send the published version of the article. 7 Manuscript Click here to download Manuscript Horvath_et_al_Manuscript- revised-final!.doc Click here to view linked References 1 2 Local and landscape-level factors are equally important drivers in shaping 3 ground-dwelling spider assemblages of sandy grasslands 4 5 Roland Horvátha,, Tibor Maguraa, Béla Tóthmérészc*, János Eichardtb, and Csaba 6 Szinetárb 7 8 a Department of Ecology, University of Debrecen, Egyetem tér 1, Debrecen, H-4032 9 Hungary 10 b Department of Zoology, University of West Hungary, Károlyi Gáspár tér 4, 11 Szombathely, H-9700, Hungary 12 c MTA-DE Biodiversity and Ecosystem Services Research Group, Egyetem tér 1, 13 Debrecen, H-4032 Hungary 14 15 * Corresponding author: 16 telephone number: +36-52-518600, Fax number: +36-52-512743 17 Email address: [email protected] 18 1 19 Abstract 20 21 Due to agricultural production the area of grasslands decreased dramatically and they 22 also become fragmented. Moreover, the proportion of landscape elements surrounding 23 the grasslands also changed considerably. Earlier studies emphasized that landscape- 24 level factors were essential in shaping arthropod assemblages of semi-natural 25 grasslands. Recently several studies demonstrated that local factors were more 26 important than landscape-level factors. Studying ground-dwelling spider assemblages in 27 sandy grassland fragments we found that out of the four investigated landscape-level 28 factors (isolation, total area of croplands in the landscape, total area of forests in the 29 landscape, and landscape diversity), only the area of the sandy grasslands around the 30 fragments was a significant predictor controlling spider diversity. The total number of 31 species, the number of generalist species and the number of hunting species increased 32 significantly with the isolation of fragments. Out of the three studied local factors 33 (fragment size, the shape of grassland fragment, and grazing intensity), only the size of 34 the fragments was a significant predictor of the diversity of specialist spiders, since the 35 number of these species increased significantly as the fragments size increased. Our 36 results suggest that both local and landscape-level factors are equally important drivers 37 in maintaining spider diversity in sandy grasslands; therefore, local and landscape-level 38 factors should be considered simultaneously during the restoration and/or management 39 of grasslands. 40 41 Keywords: fragmentation; generalist species; grazing; habitat specialist species; 42 hunting strategy; isolation 43 2 44 Introduction 45 46 Grasslands are one of the most extensive ecosystems in the world; they cover 40% 47 of the terrestrial area (Sala 2001). In the last century, due to human activities large 48 grassland areas disappeared or decreased considerably, causing serious fragmentation of 49 the remaining grassland habitats (Dengler et al. 2014). Habitat alteration, fragmentation 50 and land use changes are the main anthropogenic processes influencing grasslands at 51 local and global level; these changes caused considerable decrease in populations of 52 certain species by as much as 20-50% throughout Europe as well as change the 53 extinction and colonization rates of grassland inhabiting arthropods (Batáry et al. 2012; 54 Horváth et al. 2013). 55 Traditional management practices like low intensity, wildlife-friendly grazing and 56 mowing resulted in diverse semi-natural grasslands (Batáry et al. 2008). During the 57 second half of the 20th century the more efficient large scale farming techniques, such 58 as better drainage, chemical inputs and abandonment of traditional management 59 practices resulted a considerable reduction, alteration and fragmentation of natural and 60 semi-natural grasslands (Buchholz 2010; Habel et al. 2013; Horváth et al. 2009). Most 61 grasslands were cultivated for crops, or left ungrazed and increasingly taken over by 62 shrubbery and forest. Thus, conventionally managed, species-rich grasslands have 63 declined drastically worldwide. These processes have led to the disappearance of many 64 characteristic plant and animal species in these habitats, contributing to a remarkable 65 loss of biodiversity (Hooftman and Bullock 2012; Krauss et al. 2010; Tscharntke et al. 66 2005). Therefore, it is important that farmers and conservationists across the world re- 67 establish a network of natural and semi-natural grasslands (Ödman and Olsson 2014; 68 Poschold and WallisDeVries 2002). 69 For the maintenance of grasslands and their biodiversity at local scale, appropriate 70 management practices like grazing and/or mowing are necessary, since the lack of 71 managements or very low intensity treatments result in grasslands becoming dominated 72 by perennial rank or tussock grasses and shrubs (Albert et al. 2014; Levin, 2013). At 73 landscape scale, agricultural lands were simplified due to the decrease of landscape 74 diversity caused by the dominance of few crop species and the disappearance of natural 75 and semi-natural grasslands (Concepción et al. 2012). Besides landscape diversity, 76 fragmentation and isolation of natural grasslands have vital influence on local species 77 richness and composition (Horváth et al. 2013, 2015). All these processes have caused 78 habitat degradation, which led to a reduction in the suitability of grasslands for biotas 79 (Benton et al. 2003; Duelli and Obrist 2003). Therefore, to the increase of species 80 diversity in these habitats there is an urgent need to restore natural and semi-natural 81 grasslands and reduce their fragmentation. 82 Sandy grasslands are valuable and the most threatened habitats in Central Europe 83 (Dengler et al. 2014). Since the mid 20th century agricultural management has been 84 causing the fragmentation or disappearance of these grasslands. Thus, rare and sand 85 specialist plant and animal species are highly endangered (Faust et al. 2011; Horváth et 3 86 al. 2013). Spiders are diverse and abundant generalist arthropod predators and play an 87 important role in functioning of natural and semi-natural habitats and agricultural 88 ecosystems and in shaping arthropod communities as natural pest enemies (Horváth et 89 al. 2009, 2013; Marc et al. 1999; Picchi et al. 2016). Moreover, their taxonomy and 90 ecology are well known, they comprise specialist and web-building species which are 91 sensitive to habitat alteration caused by management regime (burning, mowing, and 92 grazing) and fragmentation (Cattin et al. 2003; Horváth et al. 2009; Valkó et al. 2016). 93 In contrast, generalist and hunting species are more adaptive, and less sensitive than 94 specialist and web-building species (Horváth et al. 2009, 2013, 2015). To understand 95 the effects of land use changes on the structure and composition of specialist, generalist, 96 web-building and hunting spider assemblages in natural and semi-natural habitats, it is 97 necessary to study these influences at both local and landscape-level scales (Batáry et al. 98 2008; Horváth et al. 2015). 99 Earlier studies demonstrated that fragment size (Horváth et al. 2013, 2015; Jonsson 100 et al. 2009; Toft and Schoener 1983) and management like grazing (Eldridge and 101 Whitford 2009; Kovac and Mackay 2009; Batáry et al. 2008; Horváth et al. 2009) were 102 the most important local factors in shaping spider assemblages. However, there are 103 several other local factors which also influence species richness and density of spiders 104 such as the shape of habitat (Barbaro et al. 2005), management types (Batáry et al. 105 2008; Picchi et al. 2016), prey density (Horváth et al. 2005). Habitat isolation proved to 106 be the most influential landscape-level factors on spiders (Horváth et al. 2013; Jonsson 107 et al. 2009), but further factors such as extent of grasslands, croplands and forests in the 108 landscape, and landscape diversity were also important (Clough et al. 2005; Schmidt et 109 al. 2008; Horváth et al. 2015; Picchi et al. 2016). There are relatively few studies that 110 investigate the effects of both local and landscape-level factors on spider assemblages 111 (Horváth