Does Habitat Fragmentation impact the species assemblage of pollinators in relict Heathlands across a UK city?

Lowland Heath is a form of ancient landscape characterised by dwarf shrub heather communities. These important ecosystems create complex mosaic habitats that support valuable assemblages of insects. Heathland is on the UK Biodiversity Action Plan (BAP) list of priority habitats (JNCC, 2007). Agricultural intensification and urbanisation have reduced this once prolific landscape to 16% of the total area of England which it occupied in 1800 (English Nature, 2002). Despite substantial urbanisation within the West Midlands, fragmented patches of heathland totaling 500 ha still remain in Birmingham and the Black Country (Trueman et al., 2013).

Researchers agree that the decline of pollinators is a cause for global concern that warrants further research (Winfree et al., 2009; Bates et al. 2011). The UK has lost 14 bee species since 1900 with a further 35 species at risk of extinction (Goulson, 2019). Although several studies have highlighted the value of urban areas to support insect populations (e.g., Bates et al. 2011; Baldock et al., 2015; Hall et al, 2016), and the importance of relict heathlands for sustaining diverse metapopulations of rare pollinators in the region (Falk, 1996; Falk and Lane, 1999; Falk, 2010), no study (to date) has focused on the impacts of urbanisation on pollinator assemblages in relict heathlands.

This research is valuable, as the regeneration of fragmented heathlands could support urban pollinators. This will inform management recommendations for connecting isolated areas of lowland heath across the region. We hope to demonstrate the need to regenerate and expand areas of relict heathland across the West Midlands, as a viable solution to insect decline. This project will examine (i) the impact of urbanisation on pollinator diversity in relic heathlands and test whether (ii) species diversity is lower in fragmented areas of heathland, compared to connected areas. It will assess (iii) the impact of geographical expansion of heathland on pollinator diversity and (iv) quantify the habitat conditions for nesting aggregates for solitary aculeates (bees & wasps).

This project provides opportunities to inform local stakeholders in the fields of landscape management and nature conservation how to regenerate areas of lowland heath for vulnerable insect species, while providing outreach opportunities for the research partnership to work with local residents. The DR will work with a multidisciplinary team of academics (landscape ecologists, insect biologists and conservationists), as well as an experienced drone operator to capture high resolution aerial images of heathland sites across the target area. The drone will produce 20 megapixel images at 300 dpi, showing the extent of vegetation coverage and bare earth in urban heathlands. This project will provide training in a range of skills to develop a pollinator database for the region, updating and refreshing current knowledge of species in the target area. This will involve utilizing citizen science to accumulate data on the geographical locations and species assemblages of important nesting aggregations throughout the West Midlands conurbation.