Richard G. Davies, Olga Barbosa, Nicholas Burke, Richard A. Fuller, Kevin J. Gaston, Daniel Lewis, Jamie Tratalos & Philip H. Warren
The growing proportion of human populations living in urban areas, and consequent trends of increasing urban expansion and densification fuel a need to understand how urban form and land use affect environmental quality, including the availability of urban green spaces. Here we use Sheffield as a case study of city-wide relationships between urban green space extent, quality (vegetation cover and tree-cover), and gradients in urban form and topography. The total area of buildings and length of the road network are equally strong negative predictors of extent of green space, while the former predictor is amore important negative influence upon green space quality. Elevation positively influences extent of green space but negatively influences tree-cover. In contrast, slope of terrain positively influences green space quality and is the best predictor of tree-cover. Overall housing density is a more important negative predictor of extent of green space and tree-cover than the densities of individual housing types. Nevertheless, the latter are more important influences upon levels of vegetation cover. Threshold effects of densities of different housing types suggest opportunities for optimising green space quality, with implications for housing policy. Variation in ecological quality of green space may partly reflect different historical intensities of industrial activity.
Throughout late antiquity, long after the collapse of the Roman administrative system, Augusta Emerita (Mérida, Spain) retained its role as a primary center for economic, political, religious, and social exchanges. However, the nature and the physical setting of many of those interactions changed significantly in this period. In particular, Emerita’s archaeological record from the fourth and fifth centuries confirms a trend away from the classical ideals that had contributed to the city’s early urban structure. This article argues that the sweeping urban changes experienced by the city are not just symptomatic of economic decline but that these changes should also be taken as important examples of the ongoing vitality of the Late Antique city center. As residents and officials encountered a new set of economic, political, religious, and social demands, they reshaped their urban environment to adapt to these new circumstances. The end result is most clearly distinguished in the remains of the late fifth-century city, but this post-Roman city has its roots in the Late Roman context of the fourth century.
