Biodiversity value of urban hedges

Abstract

Rural hedges are ubiquitous features in the British landscape and are recognised for their biological, cultural and aesthetic importance. Hedges are also present in urban settings; as relicts of previously farmed landscapes and as planted boundaries. Relatively little is known about their composition, spatial distribution nor their biodiversity value to our cities. This thesis responds to this knowledge gap by evaluating the ecological value of urban hedges in the UK with a focus on their use by birds, small mammals and insects. The research involved habitat surveys undertaken in the city of Stoke-on-Trent (2015 – 2017) to collect data including: hedge species and physical structure, surrounding land-use and floral composition of verges. Associated field surveys of birds, insects and small mammals were also completed. In addition to the ecological assessment, a photographic perception study was conducted to investigate the public perceptions of Stoke-on-Trent’s hedges. This sought to identify which type of hedge species, management style and appearance was most valued in the urban context. Results indicated that birds, insects and small mammals all preferred wide hedges with verges, associated with woody habitats. Significant preference was shown by birds and mammals for hawthorn hedges over beech, privet or non-hedged controls. For the first time, arboreal use of urban hedges by small mammals was also demonstrated. The visual and aesthetic characteristics of hedges favoured by the public were in-line with those that enhanced biodiversity. Hedges provide a range of ecosystem services as well as opportunities for contact with nature and their continued existence in cities should be supported. As such, this thesis concludes with a set of management guidelines for local authority staff to use in order to maximise their benefit to the people who live alongside them and the wildlife that lives within them.