ABSTRACT
This chapter begins by briefly exploring the ecology of natural and urban cliffs and the similarities and contrasts between the two. It then examines the Urban Cliff Hypothesis, an early framework for understanding urban cliffs, before considering the ways in which some species thrive in urban cliff environments. Natural cliffs are relatively under-explored ecosystems. The species commonly found on cliffs tend to be stress-tolerating lichens and bryophytes, though some herbaceous plants and even small trees may be found on cliff faces. Clearly urban cliffs have the capacity to support a range of rock outcrop specialists as well as more opportunistic species, if the right conditions occur. Urban cliffs are an important – and growing – element of the built environment, but their ecology, and ecological potential, remains under-explored. Greater understanding of urban cliffs may allow them to be more effectively incorporated into attempts to ecologically improve cities, particularly through the ecological engineering of more ‘biodiversinesque’ urban landscapes.
