Christine Thuring wins PhD prize for green roof research

Dr Christine Thuring

Dr Christine E. Thuring, one of the Landscape Department’s recent PhD graduates, has been awarded a prize for original contribution to knowledge from the Landscape Research Group (LRG).

Christine, who graduated in July 2016, will receive £500 and a year’s membership to the Landscape Research Group. An abstract of her dissertation will be featured alongside those of other winners in LRG’s publication, LRExtra.

The LRG is a charity, founded in 1967, to promote greater understanding of landscape. This year’s student prizes will be awarded at an official event following the LRG AGM in London on 18 May 2017.

For her thesis Ecological dynamics of old extensive green roofs: vegetation and substrates >20 years since installation, Christine applied ecological methods to some of the oldest extensive green roofs in the world. Much is known about their engineered performance, but little is known about how green roofs function over the long-term.

Most of the roofs supported multi-layered meadows, where Sedums formed a consistent ground layer beneath taller herbaceous species, like Perennial Flax, Carthusian Pink, or Perforate St. John’s Wort

Dr Christine thuring

Christine said: “This work would not have been possible without our industry partner, who facilitated access to many of the old roofs surveyed. Access is probably the biggest barrier to understanding long-term performance, given the risks of liability to the building owner. All of the roofs surveyed were owned by municipal or academic institutions, and most of the contacts with whom I interfaced were interested in the research, which proved invaluable to the logistics of the work.”

“Extensive green roofs are low-maintenance systems, so once the vegetation is established the main human activity is annual weeding. We wanted to know how the vegetation and substrates had changed twenty to thirty years after installation. Our findings show that the initially diverse vegetation of the roofs surveyed became much simpler over time.”

“Yet, and in spite of the dominance by stress-tolerators and ruderal (annual) species, most of the roofs supported multi-layered meadows, where Sedums formed a consistent ground layer beneath taller herbaceous species, like Perennial Flax, Carthusian Pink, or Perforate St. John’s Wort, and with very few grasses. This recalls the German green roof industry’s original commitment to native ecosystems and plant communities.”

“For emerging green roof industries, this suggests that species selection should not be restricted to Sedums, since species with other growth forms exhibit the strategy of stress-tolerance. The long-term floristic diversity of green roofs can be diverse and multi-layered, in spirt of harsh growing conditions.”

Since green roofs have become popular ecological interventions for towns and cities around the world, this research is relevant to urban design and planning. Christine hopes that the methods and findings will help to better connect green roof research and practice with developments in urban ecology.

Dr. Thuring is grateful for the award, and will dedicate the prize money to fund her participation/ presentation at the Green Infrastructure conference, to be held in Orvieto, Italy in April 2017.

Find out more about PhD study in the Department of Landscape here.