Faced with all these processes, we could tend to believe that "appropriating" nature (or "serving" or defending or even "messing it up" because this is our place) is an ordinary act of indigenisation that has put down strong roots in everyday Montreuil life. The head of one environmental association declares in an interview, in relation to the annual festive closure of the A83 Motorway, that "each ethnic group in Montreuil could have its own garden" as part of a big communal garden. Students are often presented with the example of the garden run by Malian women in Bas-Montreuil. Another association uses the vegetable garden (a "farm") in Murs-à-pêches to support the installation of a halting site for Rom immigrants (Écodrome).
Occupying a garden and having the keys based on permission accorded by the Council is possibly the same thing as squatting and working plots, acts that consume a huge amount of time and energy, (e.g., discarding and piling up waste), a singular means of appropriating nature indeed, much like smashing up a footpath in front of your house or feeding colonies of pigeons. In the working class areas visited, a municipal cleaning agent (off duty and looking just then like one of those "inner city youths”) told us they had been working that same morning in a particularly clean street in a smart terraced neighboured and that he had felt uneasy. He had felt as if he was suddenly in Paris. Everything was too clean, it wasn't right, it wasn't like here, it wasn't like Montreuil. Several times, better off respondents, expressing a mixture of doubt and pride, told us to go and take a look at the state of the streets at the juncture of Vincennes/Montreuil. This relatively less well-kept appearance and abundant vegetation running free could also be part of Montreuil's identity. Is it possible to lay claim to this while giving out about the municipality's failure to "look after" things?
The attention paid to these different forms of nature in the city highlights the division between learned and acceptable environmental forms in terms of public policies and other more informal ones referring to a qualified population of marginalized people. Therefore one cannot analyze the status of these environmental forms without wondering about the city as a human space and as a crucible of one's own species and spaces desired, or even controlled, at the expense of other forms described as unwanted.
After these few examples of environmental forms arising from popular ecology and a territory undergoing transformation under the influence of environmental policies, we now wish to briefly examine a public policy that involves creating environmental forms in order to effect socio-cultural urban transformations.
3.2 Greenways, a public policy
Green and blueways are examples of new spatial planning policies devised under pressure from environmentalists. Although they have been part of the urban planning tradition for more than a century for a variety of reasons (Arrif et al., 2011) such as their aesthetics or public health qualities (Ahern, 1995) they are still to become an integral part of urban policy in many countries. Environmental forms aim to organise the reproduction of genetic, specific and ecosystemic diversity, i.e., biodiversity, by means of a territorial grid (Forman, Godron, 1986). Aside from their professed contribution to citizen welfare in numerous different ways, they can also help to balance temperatures and greenhouse gas emissions and/or pollutants by cooling the atmosphere and trapping polluted particles. This is why EU countries have published rules and directives to encourage public policy to integrate Greenways at European level (Strategy for a European-wide Green Infrastructure in the context of post-2010 biodiversity European Commission Policy). French deployment of Green Infrastructure is reflected in the policy of creating greenways and it is one of the key points of the French Government's Grenelle round table on the environment: a national debate that took place in late 2007, culminating in the Grenelle I and Grenelle 2 laws (Law 2009-967 of 08-03-2009, and Law 2010-788 of 07-12-2010). These laws oblige each local government – from administrative region to urban municipality – to reflect on ways of integrating greenways into their local urban (PLU ) and metropolitan (SCoT ) planning in order to respect/create corridors that preserve links between natural spaces and help put a stop to biodiversity erosion.
Do blue and greenways comprise the "meta-form" of a social shift towards a generalised connectivity? We need to break out the components of greenways and wetlands that tend to support an ecological connectivity in a broad sense. First, developing blue and greenways relays a landscape ecology that nurtures a "landscape-type vision" of biodiversity. Second, blue and greenways benefit from a natural link forged between human communities in space and time by protecting nature. Third, from a visual perspective, mapping blue and greenways imposes a policy of relations between natural beings over and above administrative and national boundaries. Maps, drawings and diagrams that visually define greenways contain colour schemes linked by coloured lines. Indeed, deploying networks of natural spaces in the name of biodiversity preservation requires preliminary formalisation by means of an image. Generalised connectivity is contingent on drafting the form of a specifically defined network that transforms the concrete landscape and sets out the ordinary natural and built environment.
Consequently, the blue and greenway landscape, which appears diagrammatic at first, plays on abstraction in order to participate in a policy of forms. The call for papers for the March 2013 multi-disciplinary conference, "Greenways: The interconnected Pathways of Communication and the Environment"  at the University of Tennessee-Knoxville, that brought together planners, writers and ecologists, highlighted the metamorphic aspect of this new policy:
Following the natural contours of the landscape, greenways are man-made paths that work to link human communities to the surrounding environment. In the same way, this conference seeks to promote connectivity between various disciplines and their approaches to the environment.
But what is the relationship between a politically orchestrated planning policy and the reality of this form on the ground?
The French research programme "Urban Greenways" (50 researchers, 11 social science and ecology research teams) conducted an evaluation of green urban infrastructures and proposed the development of a policy framework to guide the deployment of green infrastructure policy at local level. As well as other case studies, three French cities with very different urban cultures and environmental contexts were studied: Paris (Northern France), Marseille (Southern France) and Strasbourg (Eastern France). We examined three categories of stakeholders involved in green infrastructure building: planners/inhabitants/scientists. We sought to ascertain which greenways citizens really dreamed of. Citizen discussion groups were organized . The debates between participants showed us what they see as being part of an environmental aesthetic and point up a relationship to nature that is different from one city to another. Moreover, the opinions of inhabitants show that the green infrastructure they project (as natural networks within the urban fabric) are part of a particular ethic and hark back to the specific values of situations and urban forms, stories and cultures.
Parisians are preoccupied with fauna and refer primarily to undesirable animals with strong links to humans (doves, rats). They demand that building managers limit their spatial development because they consider fauna as a potential parasite. Next, they speak of desirable animals such as squirrels, fish and rabbits. Even though Parisians would like more greenways, they cannot see how there could be place for these corridors or developments in a compact city. One Parisian remarked, "I guess that urban greenways are supposed to form grids and something that links the country to the city, but I cannot visualise that. I don't know what form that could take in a city like Paris.”
In Marseille, the issues are different and revolve primarily around public health problems. Green spaces mainly evoke questions relating to the treatment of waste (removal of waste and animal excrement) and keeping dogs on a lead. Environmental projects are not yet a priority for the inhabitants of Marseille who first need to deal with anti-social behaviour. Urban greenways are mainly bound up with the tramway built recently. Next, they are a potential link between the neighbouring hills and the town centre.
In Strasbourg, people are familiar with the concepts related to urban greenways (i.e., corridor, biodiversity). Strasbourg environmental groups explicitly refer to the expression 'greenway' (sometimes spontaneously, at the beginning of discussions). For non-ecologists, although the term itself is not specifically cited, the description of natural spaces clearly demonstrates this strong idea of continuity for the movement of plants and animals. However, it is when city dwellers use greenways in their day-to-day lives that they are best known, usually for "human" uses. Moreover, nature is a necessity and fulfills a key objective of urban living as revealed in the following comment: "I see nature in two ways: first in terms of observation – look at that space! Second in terms of "health". Observing and contemplating nature and making everyone part of this observation creates an urban fabric. The return of city to life." As regards Strasbourg, urbanisation is not incompatible with the preservation of nature. Inhabitants are willing to change their transport mode and rethink the design of their city.
In these three cases, the environmental forms comprising greenways and wetlands show that they are more or less capable of transforming human lives.