The notion of nature conservation may seem inappropriate for urban ecosystems upon ﬁrst consideration. As urban environments are often complex mosaics of different assemblages, often with limited ‘naturalness’, the idea of preserving or even improving such areas may seem either nonsensical or a waste of effort and resources. Chapters 3-6 have demonstrated that urban ecosystems may have unexpectedly high diversities, and that the species and communities within such systems may be interesting, unusual and ecologically valuable. This is a relatively recent viewpoint, however, and the history of conservation has for the most part ignored urban regions; perhaps because ‘urban’ spaces were characterised by a perceived absence of ‘nature’ (Williams, 1973). This has begun to change in recent years, as both researchers and the wider public have become more aware of the value of urban nature and ecology, and also the potential for urban nature conservation to allow society to respond to environmental change (e.g. climate change), support environmental education, ecosystem services, urban sustainability, and human health, and to behave ethically in relation to the environment. As noted in Chapter 1, there can be substantial resources brought to bear on urban conservation, and there is great potential for both ecological and societal improvement of urban ecosystems. There are three broad forms of conservation, which have varying relevance for
1 The preservation of genotypes, species and ecosystems (including the distinct communities associated with certain ecosystems). This is achieved by the isolation and shelter of organisms directly in zoos and botanical gardens (for genotypes and species), the taking and storage of genetic material for future reference, e.g. seed vaults (for genotypes and species) or the establishment of reserve areas that are protected from future harm (for genotypes, species and ecosystems). Preservation is mainly applied to natural or semi-natural areas of the globe and has relatively limited application to urban areas, though urban green spaces are sometimes preserved in recognition of their ecological or societal value (see Chapter 4).