Urban naturalistic meadows to promote cultural and regulating ecosystem services

This thesis examined the ecosystem services delivered by a new type of vegetation comprised of grasses and forbs organised in biodiverse naturalistic meadows. The study site was a 500 metres retrofitted linear greenway, the Grey to Green, installed in Sheffield (UK) city centre. A street survey showed users highly appreciated the vegetation and had an improved the perception of the urban environment and thus established the delivery of cultural ecosystem services. By means of a questionnaire and micro-climatic measurements, a thermal sensation scale for Sheffield was defined. In addition to evidence for the role of physiological acclimatisation, a link was found between appreciation of the green space and tolerance to thermal discomfort. The influence of psychological factors on thermal comfort was further investigated using a visual questionnaire. Results highlighted interactions between thermal preference, thermal expectation, landscape appreciation and long-term experience. The microclimatic regulating services of meadows was demonstrated via a yearlong comparative study of surface temperature against that of shaded and exposed turf and concrete. The results highlighted meadows have a measurable impact on reducing the Urban Heat Island effect; and, at times, more efficiently so than trees. The environmental simulation software Envi-Met was tested against field data and was showed to predict realistically surface temperature. This thesis demonstrated the usefulness of urban meadows in cultural and regulating ecosystem services delivery. They may ease surface heat accumulation, improve perceptual qualities of the urban environment and improve the sensation of thermal comfort. Thus, they contribute to making cities more liveable.