**Preface to "Ecosystem Services, Green Infrastructure and Spatial Planning"**

With regards the United Nations Convention on Biological Diversity, ratified by Italy by Law no. 1994/124, an ecosystem is "a dynamic complex of plant, animal and micro-organism communities and their nonliving environment interacting as a functional unit." Ecosystem goods and services, univocally defined as "ecosystem services" represent the benefits human populations derive, directly or indirectly, from ecosystem functions.

When trying to assess the ecosystem services of natural resources, the usual vision is always based on qualitative approaches. The importance of environmental services is generally recognized, as well as how much they are worth protecting and restoring. However, it is very difficult to compare the costs, which can be easily revealed in monetary terms, to the benefits, which are always in the abstract world of ideas. Actually, it is impossible to compare apples to oranges. It would be of huge utility for planning and managing to have tools that bridge this gap.

It has to be emphasized that the strategic environmental assessment (SEA) of management plans (MPs) for Natura 2000 sites has to be regarded as an assessment exercise concerning not merely a single node of the ecological network (that is, a single Natura 2000 site), but rather the network as a whole. SEA is intrinsically connected to sustainability because it establishes environmental protection-related objectives, and, therefore, it acts as a sustainability-oriented plan which becomes part of the planning process itself. This is of particular importance with reference to the definition of conservation measures, including the preparation of MPs, as SEA can help integrate sustainability within MP objectives and can be regarded as a real and effective learning path for the administrations in charge of Natura 2000 sites. Within the SEA, a fundamental issue is the assessment of the restoration of ecosystem services.

In the Communication from the Commission to the European Parliament, the Council, the European Economic and Social Committee and the Committee of the Regions (COM (2013) 249 final), a working definition of green infrastructure (GI) is proposed as follows: "A strategically planned network of natural and semi-natural areas with other environmental features designed and managed to deliver a wide range of ecosystem services. It incorporates green spaces (or blue if aquatic ecosystems are concerned) and other physical features in terrestrial (including coastal) and marine areas. On land, GI is present in rural and urban settings." Moreover, the Commission puts in evidence how and to what extent the issue of GI relates to the network of sites of community importance (SCI), special areas of conservation (SAC), and special protection areas (SPA): "The work done over the last 25 years to establish and consolidate the network means that the backbone of the EU's GI is already in place. It is a reservoir of biodiversity that can be drawn upon to repopulate and revitalize degraded environments and catalyze the development of GI. This will also help reduce the fragmentation of the ecosystem, improving the connectivity between sites in the Natura 2000 Network and thus achieving the objectives of Article 10 of the Habitats Directive."

Hence, it is evident that the definition of GI is strictly connected to the category of ecosystem services. Moreover, it has to be a planned network. Spatial planning, at the regional and urban levels, is an important and effective perspective to address the complex issue of defining, implementing, and managing networks of ecosystem services and GI.

As a consequence, GI has a decisive role in promoting the restoration of biodiversity and in reducing the fragmentation of ecosystems, and, eventually, in their capability of delivering ecosystem services. Therefore, a general goal of the SEA of MPs of sites of the Natura 2000 Network can be defined in order to address the issue of the role of GI in promoting and enhancing habitat restoration and the delivery of ecosystem services.

A wide range of issues related to ecosystem services and GI, as important points of reference for spatial planning, related to urban and rural contexts, with particular reference to the definition and implementation of planning policies aimed at protecting nature and natural resources, are discussed in the articles of the Special Issue.

> **Corrado Zoppi** *Editor*
