Project highlights

  • Take the lead on a new green roof experimental platform being established
  • Close involvement with industry and good potential for impact into UK practice
  • Opportunity to focus on a range of ecological and biogeochemical processes

Overview

Green roofs, vegetated rooftops designed to provide environmental and well-being benefits, are a nature-based approach to address the challenges of urbanising environments and develop more sustainable cities. They provide a range of benefits, including floodwater mitigation, thermal regulation of buildings in summer and winter, habitat to encourage biodiversity and aesthetic environments for residents. Green roof coverage is currently about 5 million square meters and increasing in the UK, but much of what we know about green roof performance comes from European and North American studies. There is a paucity of data on the performance of green roofs in the UK context and the implications for urban ecosystem functioning when present at scale. This represents a significant knowledge gap for the development of sustainable cities in the UK context. 

It is unclear how the combination of plant species and substrate type and depth influence the different ecosystem services and the long-term performance and resilience of the vegetation under a changing climate. Urban areas are typically a few degrees warmer than surrounding areas (the urban heat island effect), amplifying the impacts of a warming world and raising the question of what are the best adapted species for future conditions. Plant ecology, physiology and plant-soil interactions all influence green roof function and derived benefits, but systematic data collected under UK conditions is lacking. 

The Open University is establishing a new green roof experimental platform in partnership with industrial partner Bridgman & Bridgman to investigate how the ecology, physiology and plant-soil interactions of roof ecosystems influence their function and ecosystem service delivery. Consisting of an array of replicated 2 m2 blocks, it will enable combinations of vegetation and substrate to be investigated across a range of processes. Depending on the interests of the doctoral researcher, the research can focus on plant ecophysiological responses, botanical dynamics, energy balance, phenology, pollinator and biodiversity responses, and/or water and carbon fluxes and biogeochemistry. Collaboration with industry will ensure the project will generate data that can help shape the future of green roofing in the UK and beyond. 

A computer-generated grayscale image of a building from above showing the roof, with an array of different green roof types shown in colour on the roof, arranged in 10 blocks of 4 units each.

Figure 1: An artist’s impression of the green roof experimental platform being installed on a building at the Open University campus. Credit: Bridgman & Bridgman. 

CENTA Flagship

This is a CENTA Flagship Project

Case funding

This project is suitable for CASE funding

Host

The Open University

Theme

  • Climate and Environmental Sustainability
  • Organisms and Ecosystems

Supervisors

Project investigator

Co-investigators

How to apply

Methodology

The green roof platform will initially consist of 15-20 treatment plots replicating 3 or 4 treatments of substrate and vegetation combinations, including Sedum, wildflowers and a variety of substrate types and depth. Monitoring will include microclimate, digital imagery and water balance, with periodic soil, plant and water biogeochemistry analyses. Additional data collection possibilities include gas flux and photosynthesis measurements, leaf and surface hyperspectral reflectance, leaf traits, and plant community dynamics. Modelling city-scale impacts of green roofs from the experimental will be possible using data on roof suitability and high–resolution airborne imagery across Milton Keynes and other cities. Additional controlled experiments studies are possible through controlled environment units at the OU.  

Training and skills

DRs will be awarded CENTA Training Credits (CTCs) for participation in CENTA-provided and ‘free choice’ external training. One CTC can be earned per 3 hours training, and DRs must accrue 100 CTCs across the three and a half years of their PhD.  

You will gain experience in plant trait assessment, physiological measurements, plant survey and identification, microclimate monitoring and sample element analysis. You will receive the necessary training in all analytical techniques and instruments, and will develop your skills in experimental design, data analysis and statistical techniques. You will have opportunities to work with industry and engage with various stakeholders associated with the project. A rich and varied training programme is available to OU PG students, which includes academic writing, research design, data management, communicating your research, as well as opportunities to get involved in public engagement, media and remote digital teaching. 

Partners and collaboration

This project is a collaboration and CASE partnership with Bridgman & Bridgman, an award-winning green roof company at the forefront of the industry in the UK. They established the Green Roof Project in Milton Keynes as a training roof and to demonstrate what green roofs can offer to planners and decision makers. They will provide the material and work to establish the experimental platform, provide input and feedback from the industry perspective and ensure results are disseminated to practitioners, policy makers and other stakeholders.   

Further details

For any enquiries related to this project please contact Kadmiel Maseyk ([email protected]).  

We invite applications from students with a strong background in plant ecology, environmental physiology, green infrastructure or similar fields, an interest in urban environments and an enthusiasm for work outdoors and independent research.   

If you’re not sure whether your academic background is suitable, please contact Kadmiel Maseyk ([email protected]) or at [email protected].  We’d be happy to hear from you.  

The successful student will join well-established teams researching environmental and ecosystem processes and urban ecology in a vibrant postgraduate community at the Open University.

To apply to this project:  

Possible timeline

Year 1

Literature review, maintenance and analysis of ongoing data collection, training and first data collection for project-specific investigations.

Year 2

Analysis of first season data, national conference presentation (eg BES Annual meeting). Second season data collection and analysis, upscaling and modelling. 

Year 3

Final data collection and complete analyses. Writing up thesis. International conference presentation.

Further reading

Molineux C.J., Fentiman C.H., Gange A.C. (2009) ‘Characterising alternative recycled waste materials for use as green roof growing media in the U.K.’, Ecological Engineering, 35 (10), pp. 1507-1513. doi: 10.1016/j.ecoleng.2009.06.010. 

Vaz Monteiro M., Blanuša T., Verhoef A., Richardson M., Hadley P., Cameron R.W.F. (2017) ‘Functional green roofs: Importance of plant choice in maximising summertime environmental cooling and substrate insulation potential’, Energy and Buildings, 141, pp. 56-68. doi: 10.1016/j.enbuild.2017.02.011. 

Shafique M., Xue X., Luo X., (2020) ‘An overview of carbon sequestration of green roofs in urban areas’, Urban Forestry & Urban Greening, 47, 126515. doi: 10.1016/j.ufug.2019.126515.