Article ID: 2415
Abstract: Green infrastructure (GI) is a conceptual framework for using ecosystems to support human social infrastructure. In recent years, there has been a growing trend to view urban green spaces as GI and examine the ecosystem services they provide. In this study, we quantitatively evaluated the potential air purification function of several tree species in urban green spaces based on their absorption of trace metal pollutants. From December 2022 to January 2023, we collected fallen leaves of four species (Quercus myrsinifolia Blume, Quercus serrata Murray, Acer palmatum Thunb., and Zelkova serrata (Thunb.) Makino) from the grounds of Tokyo Metropolitan University, Hachiōji, Tokyo, Japan. We used inductively coupled plasma atomic emission spectrometry (ICP-AES) to measure the abundance of four trace metals in fallen leaves: cadmium (Cd), copper (Cu), lead (Pb), and nickel (Ni). Quercus myrsinifolia, Q. serrata, and A. palmatum all absorbed pollutants (Z. serrata was excluded from analysis due to technical problems), but differed in the extent to which they absorbed each trace metal. Acer palmatum displayed high absorption of both Cd and Cu, but was uncommon in the study area. Quercus myrsinifolia displayed high absorption of Ni only; as an evergreen species, it could contribute air purification services year-round. In contrast, Q. serrata showed relatively limited trace metal absorption; however, as a deciduous species, its leaves can be readily collected and removed from the environment. The absorption characteristics of the three species are complementary and show promise as a component of comprehensive and effective GI.
