This page aims to identify tree related research to inform good practice in urban environments. Please contact us if you have research that may be of interest to TDAG:
For updates for urban trees from Forest Research please contact:
Dr Kieron Doick
Green Infrastructure for Roadside Air Quality tool – planting in the right place
Street planting, or ‘green infrastructure’, is an essential part of the urban realm, but there is a misconception that plants remove or ‘soak up’ a lot of pollution. Instead, planting at this scale primarily serves to redistribute pollution by changing air currents within streets and beside open roads.
Clean Air, Planning and Design
Focus on the Planning White Paper – a chain of consequences for clean air.
Dr Suzanne Bartington & Dr James Levine, University of Birmingham
Tree replacement for carbon sequestration parity
In line with the net-zero commitments of the city, UBoC attempt to inform an updated tree replacement policy for Leeds City Council which ensures zero net loss of carbon sequestration in the city attributed to the required felling of trees in planned development works. Our analysis utilises the best available local estimates for rates of carbon sequestration of urban trees outside of woodlands, within the Leeds area, and uses this data to calculate tree replacement rates based on tree condition, size, and species in a new Leeds4Trees method, to provide a scientific underpinning for a revised replacement rate policy. You can find the report here, as well as the link to the summary report which illustrates the calculations.
The role of trees and greenspaces in urban climate regulation (June 2021).
A briefing note from Forest Research on the role of urban greening and climate adaptation can be found here.
Some recent papers investigating ecosystem services provision; the role of trees and urban cooling and a survey of historic urban tree canopy cover in Great Britain reviewing ten urban areas and their changing canopy cover since the 1940s.
Data reveals the power of big trees, and the impact of tree management on the benefits we derive from trees
Forest Research has compiled extensive datasets on tree benefits arising from UK-based i-Tree Eco studies together with literature from academic, industry, central and local government sources to investigate how ecosystems services provided by trees vary across 30 species commonly found in the urban landscape, and how management decisions further impact benefits derived.
Findings from this excellent work illustrate that management practices significantly influence ecosystem services delivery by urban forests through selection of the trees planted, how trees are maintained, and when and for what reasons trees are removed. This research also demonstrates that healthy large trees provide the greatest quantities of ecosystem services per tree, emphasising the importance of urban forest management that values and protects these trees.
This work is available in three separate publications:
For updates for urban trees from Forest Research please contact Dr Kieron Doick firstname.lastname@example.org
Trees and urban air quality
Role of trees & other green infrastructure in urban air quality (2019) Emma Ferranti, James Levine and Rob MacKenzie explain the role of vegetation for air quality management in our cities. https://www.the-ies.org/analysis/role-trees-and-other-green.
Using Green Infrastructure to Protect People from Air Pollution (2019) This guide summarises the current best practice for how green infrastructure can reduce public exposure to air pollution in the urban environment. It has been produced in consultation with the Birmingham Institute of Forest Research (University of Birmingham), the Global Centre for Clean Air Research (University of Surrey) and Transport for London. https://www.london.gov.uk/WHAT-WE-DO/environment/environment-publications/using-green-infrastructure-protect-people-air-pollution.
What we know and don’t know about the cooling, stormwater attenuation and carbon sequestration benefits of urban trees
Some considerable research has been and continues to be carried out on the physical benefits of urban trees in the UK, the rest of Europe and beyond. However, initial surveys of the literature suggest that, while some areas have already been well covered, the work has been carried out by many isolated groups of researchers and consequently there has been no overall methodological framework, or even consistent physical basis for their investigations. In addition, some of the benefits have only been modelled, not investigated by experiment, while in many other cases only generic benefits of “typical” trees have been quantified with little investigation of the influence of tree species or cultivation techniques. The result is that, while there is good deal of literature, it is often quite inaccessible to practitioners and the general public.
Conducted Dr. Mohammad Rahman from the Technical University of Munich and Prof. Roland Ennos from University of Hull thanks to a £5,000 Fund4Trees research grant, this project aimed to collect and review the research that has been carried out on the physical benefits of urban trees, identify what is and what is not known about them, and how best to improve our knowledge. The list of physical benefits delivered by trees in the urban environment being quite long, the research scope was narrowed to the following three areas of physical benefits which are often used as a basis for decision-making on urban greening policies and pursued through landscape design in individual projects:
“The aim of urban forestry is to improve the welfare of urban residents;
the planting and care of trees is a means to that end, not an end in itself.”
Dr. Mark Johnston (1985) Community Forestry: a sociological approach to urban forestry, Arboricultural Journal 9, 121-126