A framework for a carbon-based urban vegetation typology - A thematic review

Abstract

Generally, the carbon neutrality targets of cities underline the role of vegetation especially natural biotopes and ecosystems. City-wide carbon pool assessments have so far focussed on land cover and land use types, with the role of urban trees receiving particularly significant attention. However, the carbon sequestration and storage (CSS) capacity of various vegetation types in urban areas as well as their potential to enhance urban carbon sinks remains largely unexamined. Planning and managing urban green infrastructure (GI) requires a climate-wise strategy of CSS that provides a scalable link between habitats and individual plant species. Therefore, this study focusses on the CSS capacity of urban vegetation through a thematic review and identifies the key elements influencing CSS in cold-climate cities. The study further highlights that the basis for atmospheric carbon sequestration lies in the favourable growth and stomatal functioning of an individual plant. The CSS of individual plants forms the basis for urban GI and the ecosystem services they provide. Moreover, the growth of urban vegetation is affected by diverse urban growing conditions, which are under continuous change as vegetation is managed, used and modified by residents. Although soils are a major storage for carbon, the role of vegetation in transforming carbon from the atmosphere into soil organic carbon is fundamental. In this study, with; the understanding of the key drivers influencing CSS, we define a framework for a; carbon-based vegetation typology and discuss the links between growing conditions and maintenance practices with regard to the CSS capacity of diverse vegetation types. This framework provides a conceptual basis for further interdisciplinary research into the CSS of urban vegetation, for example, for CSS capacity modelling and life cycle assessment of urban vegetation. It also supports climate-wise planning, design and maintenance by formulating practical and science-based recommendations for multi-professional actors engaged in GI.