Measuring ecosystem services by urban species: the LIFE Urbangreen project : Preliminary results

There is growing interest about the ecosystem services provided by urban green areas, to improve human well-being in urban settings. Trees are a source of a wide range of ecosystem services, including the provisioning of resources (e.g. timber, food) and non-material goods (e.g. cultural, social), the maintenance of key ecological processes (e.g. carbon and water cycles), and the regulation of climatic events (e.g. flash floods, heat waves). It has been highlighted that planting a tree is not enough to get these benefits: when trees are planted without proper species selection, without selecting quality nursery stock, and without scheduling a sound management, they often prematurely decline, becoming source of atmospheric CO2 rather than a source of valuable benefits. Ecosystem services are often implicit and hard to quantify, thus the capacity of the different species to provide them has seldom been quantified and taken into account for urban green areas planning. The Life Urbangreen project is aimed at improving management of urban green areas maximising ecosystem benefits and helping cities to adapt to climate change. Specific actions carried out so far have been aimed at assessing the ecosystem services of widely used plant species growing in the pilot cities. Benefits have been measured by integrating eco-physiological measurements of leaf gas exchange and air particulate pollution adsorption to detailed biometric measurements conducted using a laser scanner. The project started in July 2018 in two cities: Rimini (Italy), and Krakow (Poland). Uneven aged trees and shrubs from ten widely used species with different size at maturity and persistence of leaves were selected in paved and park areas within each city. About 20 trees per species were selected within the experimental areas (200 trees measured in Rimini, 260 in Krakow). Tree diameter and height were measured in July 2018. Leaf gas exchange was measured on leaves located in different portions of the canopy of sampled tree during spring, summer, and fall. Data showed significant differences among the selected species for their capacity to assimilate carbon, to adsorb particulate, and to ameliorate microclimate through transpiration.