Astro-turfing the city: quantifying the impact of artificial lawns on the structure and function of urban ecosystems

Understanding how the management of urban habitats affects biodiversity and the provision of ecosystem services is essential for creating sustainable and liveable cities. Lawns are a major land cover in urban ecosystems, particularly in the Global North, where they can cover over 20% of city area (Hedblom et al. 2017). Although the creation and maintenance of lawns can have harmful ecological impacts (e.g., through chemical application and lack of biodiversity), they do provide a range of beneficial ecosystem services, especially relative to impermeable hard surfaces. In addition to cultural services such as recreation, lawns can mitigate flooding through rain infiltration, sequester carbon, moderate urban heat island effects, and provide habitat for biodiversity. Given these benefits, the current trend for replacing living lawns with artificial alternatives warrants urgent attention (Francis 2018). A growing desire for low-maintenance gardens and public green spaces has seen a rapid uptake in the installation of artificial lawns constructed from synthetic polymers (plastics). However, the scale of the uptake remains unquantified and the impacts on the provision of ecosystem services little known.
The PhD project will use a range of methods to quantify the impact of artificial lawns on the structure and function of urban ecosystems. Remote sensing will assess the current distribution of artificial lawns and associated temporal changes and trends in habitat. Data gathered from the client base of an artificial grass installation company will validate the remote sensing methods developed and provide insight into the motivations and management practices of artificial lawn users. RHS data gathered from gardeners will help us to understand the social drivers underlying the observed land-use change and enable us to identify optimal strategies to help facilitate the transition towards more sustainable gardening practises. Field observation and experiments will compare ecosystem functioning and the impacts of various management practises in real vs artificial grass, to include some or all of the following: (i) soil biota and soil health; (ii) aboveground habitat and biodiversity; (iii) carbon sequestration; (iv) infiltration and run-off; (v) surface temperature; (vi) shedding of microplastics.
Project outcomes will establish incentives to encourage more sustainable gardening practises. Alongside quantification of the extent and rate of the uptake of artificial grass and its impacts and the scale of these impacts on urban ecosystems. Impacts will be maximised through collaboration with the case partner, the RHS.