Introduction to the special issue ‘Urban green spaces: insights into cultural ecosystem services’

This thematic issue is based on the research program SERVEUR (Ecosystem Services of Urban Greenspace 2013-2016). It is funded by the Center Loire Valley Region in France and estimates the services rendered by ecosystems. This notion is recent. However, it has long been recognized that nature provides many benefits to human groups. Although little research has been carried out until the end of the 20th century, scientific publications have multiplied since the 1990s. But it was the Millennium Ecosystem Assessment (MEA) that popularized the concept. The definition of ecosystem services proposed by the MEA is very simple: it is the benefits that human groups derive from ecosystems (MEA, 2005). The MEA also distinguishes several categories of uses, that we will explain thereafter. The definition was inspired by those proposed in 1997 by two groups of researchers: Daily et al (1997) emphasize that ecosystem services are "the conditions and processes by which natural ecosystems and the species that compose them sustain human life and respond to his needs" and Costanza et al. (1997) present "ecosystem goods (eg. food) and ecosystem services (eg. waste assimilation)" as "the benefits that men derive directly or indirectly from ecosystem functions". The definition of the MEA takes up Daily's idea by using the term "services" to refer to the tangible and intangible benefits that men derive from ecosystems and the opinion of Costanza by including both natural ecosystems and those modified by humans as sources of ecosystem services. Its benefits are to be simple compared to the other two and to allow a flexible use of the notion. The expert assessment carried out within the framework of the MEA allowed highlighting the values of biodiversity for the life of human beings, and hence the costs of its loss, either observed or projected. The benefit of the concept of ecosystem service is now well recognized for its properties of highlighting the dimensions of the "value" of biodiversity related to human beings. It therefore focuses on aspects of ecosystems that have a direct relationship to well-being, that is to say that they can be used or appreciated in one way or another by people (Staub C., Ott W. et al ., 2011). Four main types of services are distinguished by the MEA: supply services (agricultural products, wood, drinking water, fiber and fuel, fish, etc.), regulation services (regulation of climate, floods, etc.), cultural services (aesthetic, religious, recreational and educational) and support services, which form the basis of the other 3 types of service (major geochemical cycles, soil formation and primary production) . In general, ecosystems provide many goods or products. Comprehensive assessment of ecosystem services is impossible; it is rarely performed and reveals very complex. Therefore, the SERVEUR project proposes to carry out an in-depth study on the cultural services of urban green spaces. These spaces play an essential role in social and cultural life: places of relaxation and recreation, well-being and care, where one can escape, meet or have a rest, sources of inspiration and beauty, marker of personal or collective identity, memory of the territory and traditions... Yet they are less documented in the bibliography because they include less concrete and indirect services (Maresca et al., 2011) and are certainly the most complex to grasp. Moreover, these are services that can hardly quantify or monetize. IUCN, in its panorama of ecosystem services provided by urban ecosystems (IUCN, 2013), proposes the classification into six categories: spiritual, pedagogical, recreational, scientific, aesthetic and the health service. These categories are of course not separated and some services may be applied to different situations depending on specificities related to land or individuals. …