Introduction

How to value, govern and protect the non-human creatures that share our cities, and how to do so sustainably, is a question that is increasingly occupying ecologists, politicians and conservation groups. While green space may be broadly defined as ‘open vegetated areas’ within the urban environment, and although aquatic ecosystems are also often included, such a definition masks considerable variation (Francis and Chadwick, 2013). In London, green space can refer to everything from the Rainham marshes, an extensive area of wetlands in the Thames estuary, to small private gardens, to post-industrial brownfield sites. It is now widely recognised that the urban green often represents a crucial habitat for many species. Green space abundance is used as an indicator of both ecological health and quality of life in urban areas around the world, and London scores highly in such matrices (Environment Agency, 2010). At the same time, the field of urban conservation biology has grown steadily over the last two decades (Francis et al, 2012), and while urban nature lacks the political clout or romantic appeal of wilder lands, an energetic mix of non-governmental organisations (NGOs) and voluntary sector organisations now exists with the purpose of improving people's access to and connection with urban nature, as well as surveying, monitoring and advocating on behalf of non-human species that live in, or visit, London. The first reason we might care about sustaining London's urban green, then, is that the city is home to more than just human life, and that these other species deserve political consideration.

This chapter begins by considering the recent history of green space conservation in London, before exploring the emergence of new ecological policies, in particular, the idea of a ‘green grid’. It then addresses how a move beyond connectivity to a model of ‘saturation’ may be necessary, discussing private space and conservation. While we understand that London's geographies of ecological responsibility extend well beyond the city's immediate territory, encompassing, for instance, networks of consumption and financial flows of virtual natures, we do not have the space to focus on those dimensions here. We take up the more modest task of exploring the challenge of sustaining the urban green within London's administrative area.