Urban domestic gardens (V): relationships between landcover composition, housing and landscape

The contribution to urban green space by private or domestic gardens in residential zones was investigated in the city of Sheffield, UK, as part of a wider study of the garden resource and its associated biodiversity. The attributes of 61 gardens, including patterns of landcover and vegetation cover, were explored in relation to housing characteristics and the nature of the surrounding landscape. The number of surrounding houses, and the areas of buildings and of roads were negatively correlated with garden area. The proportion of a housing parcel comprising garden increased with parcel size, although the proportion that was rear garden remained relatively constant. Garden size played an overwhelming role in determining garden composition: larger gardens supported more landcovers, contained greater extents of three-quarters of the recorded landcovers, and were more likely to contain trees taller than 2 m, vegetable patches, and composting sites. Unvegetated landcovers made greater proportional contributions as garden size declined. All categories of vegetation canopy increased with garden size, and large gardens supported disproportionately greater cover above 3 m. House age was a less significant factor determining garden landcover. Gardens of newer houses were more likely to occur towards the edge of the urban area, and older properties, that contained fewer hedges, possessed less canopy between 2-3 m. The extent and occurrence of different landcovers in gardens, and their consequences for wildlife, are considered for residential patches in urban areas. The implications for urban planners are discussed.