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SECTOR:Green/Blue COUNTRY:France

BACKGROUND
Rennes is a university town of 212 000 inhabitants which extends on 50.22 km2. With more than 7.94 km2 of greensapce, 100 000 trees, 660 family gardens, Rennes is a green city (data 2002). Since the 1980’s, the city has adopted a quality approach to cope with an increase of greenspace surface, due to the development of the city. For this reason, it has diversified the greenspace offer instead of horticultural gardens only. Thus, it has developed a differential conception of greenspace, based on an extensive management of the greenspace contrary to the intensive practices which is the norm in France, where the “jardins a la francaise” are typical. Thus, Rennes is one of the first French towns to implement a greenspace differentiated management inspired by experiments carried out by some cities of Northern Europe.
This quality approach results in (tab. 1, fig. 2 & 3):

• a specific management of the greenspace, in close link with their geographical localization, their use and their history (maintenance adapted to each case according to Rennes context);
• a soft management of the vegetal compositions and landscape units (lawns mowing, hedges trim, trees pruning, ponds clearing),
• an ecological design of flowers beds and stand in downtown areas
  

This new conception of differentiated management is more ecological. The cultivation methods are directed to increase greenspace biological potentialities, to ensure multiplication of shelters to favour fauna and flora as well as to manage natural resources more sparingly.

EVALUATION
Differentiated management makes it possible to improve the availability of greenspace in the urban fabric (in 1977, 393 ha were managed by the municipal parks and gardens services, in 1997, 780 ha, that is to say, double). Moreover, this management has widened the scope of parks and gardens, has introduced new landscapes and new natural rural habitats in the city (meadows, ponds, etc). Rennes has set up biological corridors and green malls in order to increase the diversity of natural infrastructures. This green frame has been used to extend pedestrian and cyclists thoroughfare, to increase the presence of natural elements in the urban fabric.

The evaluation related to environmental, economic and social dimensions.

Environmental dimension
Water: It’s preservation is ensured by a reasoned and integrated management (reduction in the frequency of watering and water quantities), by a protection of the springs and drinking water collecting areas, and by a source control of green waste production and/or pollutants emissions. The immoderate use of manure, pesticides and weeding is a significant source of water pollution in the urban environment. The moderate use of pesticides and the use of alternative techniques should tend to decrease this type of pollution.

• Soil: The differentiated management has a driving effect. It enhances the territory, and enables urban landscape preservation. It generates an increase of managed surfaces and a better distribution of greenspace over the whole urban surface.
• Vegetation wastes: those vary according to the type of vegetal structure. The quantity decreases with the minimum maintenance and with the rational use of manures.
• Biodiversity: greenspace management integrates protection and increase of the biodiversity (news hedges with various layers, herbaceous edges on pond banks (Cf. fig. 2)).

Economic dimension
Differentiated management has been a means of setting up cost accounting of day to day greenspace management and maintenance tasks. The software tool makes it possible to establish financial calculation of maintenance and to highlight the average annual maintenance costs for each maintenance class (1, 2, 3…). On the one hand, one can note, that the extensive lawn is cheaper than an intensive lawn. On the other hand, within the ten years, between 1979 and 1989, the costs fell by 25% for spaces with marked horticultural vocation (class 1) and those with simple horticultural vocation (class 2) and from 60 to 65% for the extensive greenspace and those of a rustic vocation (classes 4 and 5). The economical aspect is more noticeable for these last types (fig.1).
Personnel productivity is a relevant indicator to measure the profits released by a differentiated management. It passed from a ratio of 1.01 ha/ gardener/year (386 employees for 393 ha) in 1977 to 2.06 ha/ gardener/year (378 people for 780 ha) in 1997.
Differentiated management proves to be a partial response to the economic problems of the cities (reduction in manpower and credits).

Social dimension

• Taking into account social request related to park and historical gardens attendance as well as aesthetic and cultural links which make the charm of parks and gardens in the downtown area of Rennes.
• Recreation: the possibility of practising sports activities, recreational activities in open air, relaxation activities in greenspace close to its residence (parks, gardens, public gardens, sports field, etc.), to be in permanent contact with diversified natural spaces (lawns, meadows, forests, etc.) take part in the improvement of inhabitants’ lives.
• Education, training: the presence of nature in the city familiarizes young people with nature. School camps can be organized, on site practical work via school. Children become aware of what is at stake, which will make them more responsible when they reach adulthood.

Certain private individuals adopted differentiated management in their own private gardens. They increased the range of shrubs and decorative plants in "copying" the principles of design and in "imitating" plant compositions developed, here and there, by the town of Rennes.

Communication, information, dialogue

• The public: public information has been done through various means (municipal newspaper, radio programs, exhibitions, open days, guided tours, information installation, panels, etc.). Dialogue has been organized using public meetings, investigations, discussions with citizens and associations.
• The personnel: gardeners knowledge and training are of primary importance for the success of differentiated management (professional practices modification, acquisition of a good knowledge of biological balances, etc). The publicity campaigns were carried out using an audio-visual set up, guided tours, on site supplemented meetings. Thus the personnel have maintained a regular assessment of the carried out tasks and of greenspace evolution. This enables the monitoring of the scheme’s effectiveness and the correction of its main defaults.
  

BENCHMARK DATA
There are no national standards on differentiated management. Greenspace designers and managers must nevertheless conform to a general technical document to which the public markets refer.
However the experiment of Rennes took as a starting point European examples carried out in Netherlands (Zwolle, Zotermer), in Switzerland (Zurich, Lausanne, Geneva) or in Germany (Augsburg, Freiburg).

DRIVERS
The project and its practical application has been carried out and coordinated by the park and garden services of the town of Rennes. The legal framework on a national scale concerning greenspace management is weak, even non-existent. In fact city planning documents preserve the existing greenspace (inconstructible zone) and the creation of new ones (land reserve).
Rennes urban greenspace differentiated management falls within a sustainable development policy (environmental respect, taking into account of the inhabitants request to have local natural greenspace, maintenance expenses discount). Its objective consists in meeting the needs of an increasing social demand for nature in downtown, without increasing the cost of this service by raising local taxes.

LESSONS LEARNT
The two principal barriers to a good greenspace differentiated management are as follows:

• the inhabitants, at least in France, remain very attached to greenspace cleanliness and to a model dominated by structured and ordered gardens. This is why, the installation of a differentiated management must be progressive, graduated, to proceed by small successive steps, to take into account the social context and surrounding urban fabric.
• greenspaces are an urban facility of general interest. They have social, cultural, ecological, and landscape functions. Differentiated management implies a minimum of support from the inhabitants. This implies information and dialogue which have to be unceasingly renewed with the residents, the users, associations, teams of gardeners and local councillors.

APPLICATION
For several years, many French cities have followed the example of Rennes: Orleans, Nantes, Montpellier, Mulhouse, Lyon. The French Engineers and Technicians Association (AITF), the National Centre of Territorial Staff Training (CNFPT) as well as the Parks and Gardnens Directors Association are good conveyors for communication, to inform and share the experience feedbacks. Certain cities tried to apply this innovative approach hastily, without any prior preparation or training of their gardeners for their new trade. As a result: the inhabitants have the feeling that the greenspaces are not as well kept as than before and to show their disapproval they press councillors to end the experiment.
Using differentiated management implies taking into account the local context (citizen’s perception, employees’s training, proper governance). A demonstrative area could be a sensitization tool. Because of a lack of agreement between elected representatives, technicians and inhabitants, many cities do not try to realise this possible failing experimentation.

Figure 2: An example of class 1 (Cf.Tab 1) greenspace: Thabor Park

TRANSFERABILITY
The experiment of the town of Rennes constitutes an adaptation of other European cities practices. It was in turn adopted and adapted to other French cities.

IMPACT ON SUSTAINABILITY AREAS
This action does not have a strong irreversibility.
Environmental: high
Social: high
Economic: high
Institutional: medium

Figure 3: An example of class 5 (cf Table 1) greenspace: Gayeules pond. The high grass edges which girdle the pond are not mown in order to preserve the ecotones.

PROJECT CONTACT
Pierre LHOUMEAU,
directeur du service des parcs et jardins de la ville de Rennes
5, bd de la Duchesse Anne
35000 Rennes - France
téléphone : +33 2.99.28.56.62
fax : +33 2.99.28.58.44
email : jardins@ville-rennes.fr
web site : http://www.ville-rennes.fr/

REFERENCES
CERTU, Composer avec la nature en ville. Editions Certu, 2001, 376 p.
CLEMENT (Gilles) et EVENO (Claude), Le Jardin planétaire, Editions de l’Aube, 1997.
DOBNER (Maria), Incidence de la réintroduction biologique, Actes du colloque européen : « Vers la gestion différenciée des espaces verts, CNFPT, AIVF, 1994, p. 141-144.
LE RUDULIER (Jean), Présentation de l’expérience de la ville de Rennes, Actes du colloque européen : « Vers la gestion différenciée des espaces verts, CNFPT, AIVF, 1994, p. 61-66.
PEPIN (Denis), LEMAIRE (Christine) et collaborateurs, Le code vert : pour des espaces verts plus naturels dans l’agglomération rennaise, District de Rennes, AUDIAR, 1995, 52 p.
SCHMIDT (Horst), Bilan économique de la gestion différenciée, Actes du colloque européen : « Vers la gestion différenciée des espaces verts », CNFPT, AIVF, 1994, p. 162-166.
SCHNEIDER (Pierre) et LE BOZEC (André), La production des déchets végétaux des espaces verts publics. Résultats d’une enquête nationale auprès des villes françaises, Editions CEMAGREF, groupement de Rennes, 1995, 112 p.