Linking Mesoscale Landscape Heterogeneity and Biodiversity: Gardens and Tree Cover Significantly Modify Flower- Visiting Beetle Communities
Total Page：16
File Type：pdf, Size：1020Kb
Linking mesoscale landscape heterogeneity and biodiversity: gardens and tree cover significantly modify flower- visiting beetle communities Article Published Version Creative Commons: Attribution 4.0 (CC-BY) Open Access Foster, C. W., Neumann, J. L. and Holloway, G. J. (2019) Linking mesoscale landscape heterogeneity and biodiversity: gardens and tree cover significantly modify flower-visiting beetle communities. Landscape Ecology, 34 (5). pp. 1081- 1095. ISSN 1572-9761 doi: https://doi.org/10.1007/s10980- 019-00822-x Available at http://centaur.reading.ac.uk/84497/ It is advisable to refer to the publisher’s version if you intend to cite from the work. See Guidance on citing . To link to this article DOI: http://dx.doi.org/10.1007/s10980-019-00822-x Publisher: Springer All outputs in CentAUR are protected by Intellectual Property Rights law, including copyright law. Copyright and IPR is retained by the creators or other copyright holders. Terms and conditions for use of this material are defined in the End User Agreement . www.reading.ac.uk/centaur CentAUR Central Archive at the University of Reading Reading’s research outputs online Landscape Ecol (2019) 34:1081–1095 https://doi.org/10.1007/s10980-019-00822-x (0123456789().,-volV)( 0123456789().,-volV) RESEARCH ARTICLE Linking mesoscale landscape heterogeneity and biodiversity: gardens and tree cover significantly modify flower-visiting beetle communities Christopher W. Foster . Jessica L. Neumann . Graham J. Holloway Received: 30 August 2018 / Accepted: 20 April 2019 / Published online: 3 May 2019 Ó The Author(s) 2019 Abstract Results The composition of immediately adjacent Context Maintaining biodiversity in multifunction habitat (30 m) and mesoscale landscape heterogeneity landscapes is a significant challenge. Planning for the (200 m) explained unique portions of the variation in impacts of change requires knowledge of how species flower-visiting beetle communities. A number of respond to landscape heterogeneity. Some insect species, including those affiliated with deadwood groups are known to respond to heterogeneity at the habitats, were positively linked to tree cover in the mesoscale, defined here as hundreds of metres. surrounding mesoscale landscape. Gardens covered a However, for many taxa these effects are poorly smaller area than trees but modified beetle communi- known. ties to the same extent. Objectives To identify key elements of mesoscale Conclusions The local abundance of some flower- landscape heterogeneity influencing community com- visiting beetles is modified by the composition of the position in flower-visiting beetles, and whether land- surrounding landscape. Results highlight the impor- scape explains any variation in beetle communities tance of tree cover for maintaining insect biodiversity beyond that driven by immediate habitat cover. in agricultural landscapes, while suggesting that Methods Flower-visiting beetles were sampled from gardens associated with small urban areas may have 36 transects, laid out using a 6 km2 grid located in a disproportionate influence on biodiversity. southern Britain. Landscape heterogeneity was mea- sured for 30 and 200 m buffers around the transects Keywords Flower-visiting beetles Á Landscape and the relative response of beetle communities to heterogeneity Á Landscape mosaics Á Mesoscale each assessed using ordination analyses followed by landscape Á Urban biodiversity variation partitioning. Introduction C. W. Foster (&) Á G. J. Holloway Centre for Wildlife Assessment and Conservation, School of Biological Sciences, University of Reading, Reading, The need for landscapes to maintain or even exceed UK current levels of biodiversity is well recognised, with e-mail: [email protected] both governmental and non-governmental conserva- tion strategies increasingly adopting landscape-scale J. L. Neumann Department of Geography and Environmental Science, approaches (Lawton et al. 2010). This is a significant University of Reading, Reading, UK 123 1082 Landscape Ecol (2019) 34:1081–1095 challenge in lowland mosaic landscapes where urban mitigation for single housing developments, or to the development and agricultural intensification have spatial optimisation of agri-environment schemes at a fragmented habitats over long timescales, with vari- farm scale. These processes would ideally take able but consistently negative impacts on biodiversity account of biodiversity in all elements of the land- (Andre´n 1994; Haila 2002; Fahrig 2003; Kappes et al. scape, but whilst the synergistic effect of complete 2009; Fletcher et al. 2018). Successful management of landscape mosaics has been shown to have an impact landscapes for wildlife requires an understanding of on community composition, species communities how landscape heterogeneity determines patterns of drawn from multiple mosaic components are less species distribution and modifies community often considered (Bennett et al. 2006; Neumann et al. composition. 2016b; Duflot et al. 2017). This is perhaps due to the Landscape heterogeneity can be considered a challenge of gathering data from multiple habitats and function of both landscape composition—the amounts taxonomic groups; methods that rapidly capture a of different habitat cover types within the landscape— ‘snapshot’ of landscape biodiversity by sampling a and landscape configuration, i.e., the heterogeneity of single species community would facilitate this. their spatial arrangement (Fahrig et al. 2011). Land- Flower-visiting beetles cover a range of habitat scape heterogeneity is recognised as a key driver of affiliations within a single well-studied order, but few species distributions in lowland agricultural land- studies consider the effect of landscape heterogeneity scapes for many taxonomic groups including birds on their distributions (Sjo¨din et al. 2008; Horak 2014). (Fuller et al. 1997; Virkkala et al. 2013; Neumann Among the flower-visitors are saproxylic beetles (one et al. 2016a), bees and wasps (Fabian et al. 2013; of the most threatened groups of species in Europe Steckel et al. 2014), mammals (Mortelliti et al. 2011; (Ca´lix et al. 2018) as well as many phytophagous and Bender and Fahrig 2012) and plants (Jules and predatory species associated with tall sward and scrub Shahani 2003). habitats. By focussing on flower-visiting beetles, this However, whilst landscape conservation or land- study aims to provide a window into how mesoscale scape planning tends to consider landscape from an landscape heterogeneity influences the distribution of anthropogenic point of view, perhaps at a kilometres- a diverse insect assemblage across a lowland agricul- wide scale, there is no single ‘landscape scale’ tural mosaic. relevant to all species groups (Schweiger et al. 2005; Sampling was carried out on linear patches of Ekroos et al. 2013; Fuentes-Montemayor et al. 2017). flowering plants in the Apiaceaea (e.g., cow parsley, Highly mobile species groups such as birds or Anthriscus sylvestris, and hogweed, Heraclium spho- Orthoptera respond to landscape composition even ndylium), which are very abundant in a range of when examined at fairly broad scales, e.g., cricket lowland habitats across Northern Europe. Apiaceaea species richness in 10-km2 (Cherrill 2015) or bird attract a diverse variety of insect visitors (Willis and community composition in 2-km tetrads (Neumann Burkill 1892; Zych 2007a) and are key plant species in et al. 2016a). For invertebrates with more limited some ecological networks (Zych 2007b; Pocock et al. dispersal power, landscape heterogeneity within a 2012). Their tendency to grow in dense stands radius of hundreds of metres is important, as seen for alongside public roads and footpaths facilitates access ground beetles (Carabidae) at a 400-m radius (Barbaro to ready-made sampling transects. We also restricted et al. 2007; Barbaro and Van Halder 2009) and sampling to Apiaceaea in order to reduce variation Lepidoptera, hoverflies (Syrphidae) and bees at 600 m arising from e.g. flower preference among beetle (Sjo¨din et al. 2008). In common with Barbaro et al. species, which is not the focus of this study. (2007), we describe this as a mesoscale landscape. We asked the following key questions: (i) Is there a This spatial scale is comparable to the size of common unique contribution of mesoscale landscape hetero- units of land management, with many new housing geneity to flower-visiting beetle community compo- developments in the United Kingdom, for example, in sition apart from as a predictor of the immediate the range of 5–20 ha. presence of suitable habitat? (ii) Which elements of Links between mesoscale landscape heterogeneity landscape heterogeneity are the most important and biodiversity might therefore be successfully drivers of community composition? and (iii) In what applied to the planning of new habitat networks as way do they shape the community? 123 Landscape Ecol (2019) 34:1081–1095 1083 Appropriate scales of response to represent mesos- Beetle sampling cale (200 m buffer) and immediate habitat (30 m buffer) in the case of flower-visiting beetles were Each transect was surveyed three times by a single determined a priori from published estimates of beetle observer. The first visit was made between 16th May dispersal distances. The response of beetle communi- and 10th June 2013, the second between 26th June and ties to these two spatial scales was compared using 8th July 2013 and the third between the 10th and 26th variation partitioning. July 2013. Sampling was carried out between 10 a.m. and 6 p.m.