The first local workshop of the LIFE VEG-GAP project in Bologna was held on Friday 25 October. A morning meeting and discussion, at the headquarters of the Metropolitan City “Palazzo Malvezzi”, organizer of the workshop, to present the first months of activity of the "Vegetation for Urban Green Air Quality Plans" project in the Bologna area. Representatives of the institutions that are an active part in VEG-GAP and some directors and stakeholders participated in the worktable. For the former, the task of illustrating to the "guests" the aims, characteristics and progress of the project involving municipalities, universities, research institutes and companies.
After the institutional greetings and the introduction by Marino Cavallo, head of European projects office of Cabinet of the Metropolitan City of Bologna, Mihaela Mircea of ENEA, coordinating body of VEG-GAP, recalled in the opening the two main objectives of the project: first of all to develop a strategy to produce new reliable information to support the design of air quality plans taking into account the characteristics of the vegetation in the urban areas; secondly, to develop and implement a framework (IT platform, guidelines and other support tools) that consistently and realistically considers the link between air pollution and vegetation characteristics. All this as a basis for providing decision makers with data and information to develop effective strategies for controlling air pollution and mitigation/adaptation to climate change. For this reason we are proceeding to map the vegetation characteristics in the project’ cities (Bologna, Milan and Madrid) in order to estimate the contribution of vegetation both as a source and as a filter for atmospheric pollution and to understand the effect of vegetation on temperature.
Giuseppe Cremona, researcher at ENEA, explained how is being carried out the plant mapping of the existing public green areas in the city of Bologna. The information provided by theMunicipality census of plants of boulevards, parks, gardens and green areas is aggregated on 1 km side cells. This has already made possible to estimate the distribution of public green areas in the city, with a details including the plant species and their dimensions.
Sandro Finardi of ARIA-NET instead explained how a detailed mapping of urban vegetation is essential to calculate biogenic emissions of volatile organic compounds (BVOC). Vegetation cover description with species detail is needed together with meteorological conditions, including temperature and solar radiation, which affect plants physiology. It is worth noting that different plant species can generate different amounts of substances that can contribute to ozone and secondary aerosol production. Therefore, a detailed description of the vegetation species is needed. Finardi added that the existing land cover databases cannot satisfy this need, so a new dedicated mapping was built within the project taking into account the existing public green inventories in the three partner cities, which localize and describe the individual tree features. The mapping has shown that plane tree and Mediterranean hackberry are the most frequent species in Bologna and Milan (about 30% of the total). 229 species have been counted in Bologna, 264 in Milan and 418 in Madrid, although some thirty species represent 90% of the total vegetation cover. The researcher then explained that in-depth investigations are now focusing on species responsible of the major contributions to biogenic emissions.
A common requirement emerged is then to find ways to map also the private green area, which is supposed to have a coverage similar to that of the public green in the city, but no detailed data are presently available. The theme was reported by Teodoro Georgiatis and Rita Baraldi from CNR-IBIMET. The VEG-GAP project, they clarified, can be used as a stimulus to start collecting this type of information. Giovanni Fini, coordinator of the environmental sector of the Municipality of Bologna, intervened underlining that a census of the private green is starting within the provisions foreseen by the new municipal urban plan. Francesca Putignano, representative of the Municipality of Milan, added that the plant-by-plant census of private green is fundamental for the city of Milan too, but that it will not be able to be carried out within the VEG GAP project. Mauro Bigi, head of special projects on sustainability of the Foundation for Urban Innovation, highlighted the need to have a mapping scale of less than one square kilometre. This is a need shared by all and on which we will work. Mihaela Mircea recalled that, at present, the mapping by cells identifies the possible presence of trees in a specific area, after which we intend to detect the biogenic emissions and therefore the concentration of pollutants in that specific cell. This will serve to make simulations of vegetation scenarios, evaluating the impact of future variation of the plant species and their surface area cover.
The directors present and the representatives of the associations were very interested in the first results of the project. For Barbara Negroni, councillor for the quality of the environment and the territory of the Municipality of Casalecchio di Reno, near Bologna, the more interesting result of the project would be the knowledge of which plants would be better choose in certain areas, because the administrators need detailed information to support their decisions. On the other hand, understanding the data needed by researchers to improve their job - he underlined - is a central issue for the administrators. The councilor also highlighted the importance of the IT platform, which will contain all the information provided by the project and it will be crucial to carry out adequate communication on the various project aspects, both towards stakeholders and citizens. of the relevance of correct and effective communication was agreed by all the workshop participants.
Maria Rosa Amorevole, president of the Santo Stefano district of Bologna, noted that it would be desirable to have user oriented, easily usable results starting from the data providedby the project. He recalled the landscape constraints and the refusal of the superintendencies to allow the replacement of specific plant species in certain historical urban contexts. Last but not least, it should be taken into account: the management cost borne by the public bodies and the limits imposed to planting activities by various issues including safety and urban decay.
For Daniele Ara, president of the Navile District of Bologna, there is a great need for technical and communication skills and the dissemination of the information provided by the project will be a great opportunity to involve and sensitize citizens. Emphasizing that public green areas are expected to increase in Bologna over the next few years, Ara considers VEG-GAP a perfect tool to help making smart choices on the most suitable and least expensive species to manage, because the future economic sustainability of urban green is not a secondary aspect.
Giulio Kerschbaumer, director of Legambiente Emilia-Romagna, noted the great usefulness of the information obtained from the project in order to provide tools to support the administrators. These should then be helped to explain to the public their choices, such as the possible need to cut or replace vegetation, and citizens should be involved and made an active part of the process.
Rita Baraldi has also paid attention to meadows mowing, a green resource that should be taken into account and whose effects should be investigated. A green areas management aspect that must deal seasonal allergies prevention activities, which very often include the mowing of the lawns to reduce public health problems.
Chiara Marini, representative of the Aria Pesa association, invited to give confidence to the ability of citizens to collect and provide important information for the project, concerning in particular the private green space. Condominium administrators and organized neighborhood groups may be able to provide data on the consistency and variety of plants in private areas.