Managing biodiversity in upland calcareous grassland landscapes: A case study of spiders and ground beetles

PREFACE: This document is the product of a research project that examined the impacts of contrasting grazing management on plants, carabid beetles and spiders in upland calcareous grasslands and associated habitats in Britain. The project was funded by Edge Hill University and conducted by researchers at the same institution between 2013 and 2017. The initial project idea was developed following discussion with Natural England site managers who highlighted a knowledge gap on the impacts of commonly used management practices. Throughout the project a series of meetings were held between the authors and practitioners from a range of organisations involved in upland calcareous grassland management (including: Natural England, The National Trust, The Yorkshire Dales National Park Authority) to ensure research was as relevant and as reflective to practice as possible. This document summarises results of this project and makes management recommendations based on these results and wider information known about the ecology of spiders, beetles and plants. The full project can be accessed at: https://www.edgehill.ac.uk/biology/calcareous-grassland-research/. Details of publications resulting from this work are available from the authors or: https://www.researchgate.net/profile/Ashley_Lyons/publications?pubType=article. Suitability of management recommendations presented in this document were discussed with practitioners, academics and graziers at the Upland Calcareous Grassland Workshop at Ingleborough NNR on 15th August 2017, and where required they were amended based on input from the workshop. The document has been written in discussion with Natural England and is intended to assist conservation practitioners and policy makers in making management decisions that contribute to the conservation of spiders, ground beetles and plants in upland calcareous grassland landscapes. The authors would like to thank Richard Jefferson, Colin Newlands, Martin Furness, Claire Pinches and David Key of Natural England for helpful discussion when planning this document, along with all participants at the Upland Calcareous Grassland Workshop for their input. Thanks is also extended to the Agroecology group at Georg-August University Göttingen for hosting Ashley Lyons when conducting further research for this project. Thanks also to the Belgian Arachnological Society ARABEL and Jim Lindsey for kindly providing spider images and to Thom Dallimore for producing illustrations of grassland structure. Particular thanks to Jacqueline Loos, David Key and Colin Newlands for their helpful reviews of this document prior to publication. Funding for this project was provided by The Stapledon Memorial Trust and Edge Hill University. Cite this document as: Lyons A., Oxbrough A. and Ashton P.* (2018) Managing biodiversity in upland calcareous grassland landscapes: a case study of spiders and ground beetles. Edge Hill University, Lancashire, UK. Pages 1-36. ISBN: 978-1-900230-62-9 * Corresponding author: Paul Ashton, Edge Hill University, [email protected]

The response of ground-dwelling spiders (Araneae) and hoverflies (Diptera: Syrphidae) to afforestation assessed using within site tracking

In many countries throughout the world, the area of plantation forests continues to increase and they now dominate many landscapes. In recent decades, forest cover in Ireland has expanded largely due to commercial afforestation with non-native conifers. This study provides the first within-site assessment of the response of two important arthropod groups to afforestation in agricultural grasslands in Ireland. Five sites were studied 1 year before and 7 years after afforestation using pitfall trapping for active ground-dwelling spiders and Malaise trapping for hoverflies. Both species groups were studied in grassland habitat, and spiders were also sampled in field boundary hedgerow habitat. Afforestation within the study sites had a positive effect on ground-dwelling spider diversity over the first 7 years; total species richness increased in afforested grassland and hedgerow habitats, and forest specialist species richness increased in afforested grassland habitat. This was concurrent with, and most likely influenced by, the increase in habitat structure created by the forest vegetation, litter and deadwood layers and the increase in canopy cover. There was no effect of afforestation on hoverfly species richness over the first 7 years, possibly due to confounding effects of hoverfly movements across landscapes. Spider and hoverfly species compositions were also positively affected by afforestation. These results indicated that afforestation in our study sites, set within a predominantly agricultural landscape, benefitted arthropod diversity by increasing habitat diversity. Hedgerow habitats were also an important contributor to biodiversity in these newly planted forests. Ecologically oriented planning and management of afforestation must consider the influence of habitat quality in forest plantations, including the protection of biodiversity rich habitats and the quality of the land being afforested, to improve the contribution to biodiversity enhancement and conservation

Can ground-based assessments of forest biodiversity reflect the biological condition of canopy assemblages?

© 2015 . Biological assessments of forest systems often involve a single ground-invertebrate sampling method that may ignore the biological component of the non-sampled canopy. Pitfall trapping for ground-active arthropods is a widely implemented technique for biological assessment in forested and open habitats. Although much evidence highlights the biases of pitfall trapping, this evidence typically comes from open-habitat crop and grassland systems. In forest systems where much of the biodiversity is found within the above-ground structure, management recommendations based solely on ground sampling may not represent the diversity within the three dimensional forest habitat. We provide evidence from combined ground and canopy sampling of three major forest types within the study region. We use canopy insecticide fogging to compare with more traditional ground-based pitfall trapping, and use spiders as a comparative species-rich biota that is able to colonise most terrestrial habitats and is strongly affected by changes in environmental condition.We identified 3933 spiders from 109 species from the 18 forest patches sampled. Both types of sampling defined differences in community composition between forest types in a similar manner; hence, either method could be used to evaluate differences or test management regimes in well-replicated experiments of forest type. However, the association in community composition between ground and canopy assemblages at the individual site-based level was weak; we found low correlation between the two data sets indicating that surrogacy between methods was not supported at this level. Furthermore, disparities in spider habitat association, body size, hunting guild and vertical stratification of spider families indicates that where detailed species and family-based information is required, or if inventorying is necessary, then multiple targeted surveys are essential