Habitat associations of epigeal spiders in upland calcareous grassland landscapes: the importance for conservation

Abstract

Upland calcareous grassland landscapes are typically comprised of a matrix of calcareous grassland, acid grassland and limestone heath plant communities. This matrix of habitats is produced by a combination of underlying geology, climate and management. These landscapes are typically managed through grazing, with management targeted to maintain particular plant communities in the calcareous grassland habitat, whilst patches of acid grassland and limestone heath are not targeted by conservation management. The biodiversity value of acid grassland and limestone heath patches within the calcareous grassland matrix are unknown. This study provides the first assessment of their biodiversity value by examining aspects of epigeal spider diversity supported by these non-target habitat patches in comparison to calcareous grassland. Spiders were sampled in each habitat from April to August 2014 using pitfall traps across three upland regions in Great Britain. Spider species assemblages were distinct between limestone heath and both grassland types. Distinction in species assemblages are likely due to differences in vegetation structure and microclimate, e.g., humidity, degree of shade. Each habitat type supported several rare species (e.g., Jacksonella falconeri, Agyneta subtilis) revealing the contribution Communicated by David Hawksworth. Electronic supplementary materialThe online version of this article (https://doi.org/10.1007/ s10531-017-1488-4) contains supplementary material, which is available to authorized users. to spider fauna. The distinct spider species assemblage and presence of rare species in limestone heath patches demonstrate their importance in the upland calcareous grassland matrix. This study highlights the value of monitoring biodiversity in non-target habitats within a habitat matrix alongside those that are actively targeted by management.

Friend and foe? The effects of grassland management on global patterns of spider diversity

“…The effects of grazing on spiders are usually in accordance with the general trend found in other taxa, where low to moderate grazing regimes may support higher spider taxonomic and guild diversity (Vona-Túri et al, 2017;Szmatona-Túri et al, 2018;Lyons et al, 2018a;Ferreira et al, 2020), whereas heavy grazing (e.g. high density of grazers) is related to negative impacts on spider diversity (Polchaninova et al, 2016;Hashemi et al, 2019;Torma et al, 2019).…”

Macrohabitat associations and phenology of carrion beetles (Coleoptera: Silphidae, Leiodidae: Cholevinae)

“…The Alice Holt unforested site had significant losses giving a total of 28 trapping days. Across sites the data was standardised by dividing the number of individuals in each species by the number of trapping days at that site and multiplying it by the maximum number of trapping days (70) across all sites, following Lyons et al (2017). All analyses were carried out using the statistical programme R (version 3.2.0) (R Development Core Team, 2016).…”