The role of urban forests in tackling air and soil pollution in Italian cities

Urban forests are increasingly recognized as essential components of sustainable city planning, offering multifunctional ecosystem services that address key environmental challenges. This review explores the role of urban vegetation in mitigating air and soil pollution, using Italy as a representative case study. Air pollution - specifically particulate matter (PM), nitrogen dioxide (NO₂), and tropospheric ozone (O₃) - remains a critical health concern in urban areas, while soil contamination by heavy metals and organic pollutants continues to degrade ecosystem functionality. We examined the mechanisms by which urban greenery mitigates these pollutants, focusing on species-specific traits, functional planning, and integrated monitoring strategies. To bridge research and practice, a new strategy for urban greenery planning is proposed, presented here as two case studies. The case first demonstrates an innovative air quality management approach in Florence, combining high-resolution satellite imagery with a new simple biophysical modeling framework (FlorTree model) to evaluate species effectiveness in pollutant removal. The second case synthesizes field-scale phytoremediation projects across Italy, showcasing how selected tree, shrub, and herbaceous species can remediate contaminated urban soils while providing co-benefits such as biomass production and biodiversity support. These findings highlight the global relevance of urban forestry as a low-impact, cost-effective strategy to enhance environmental quality and public health. By integrating green infrastructure into urban policy and land use planning, cities can optimize air and soil remediation, promote ecosystem resilience, and contribute to climate adaptation goals. The review underscores the need for interdisciplinary collaboration, long-term monitoring, and policy alignment to fully harness the potential of urban forests in addressing complex urban pollution dynamics.