Zheng’s PhD research focused on natural ecosystem mimicry to improve green roof performance and ecosystem services, especially hydrological performance.
Green roofs can be an efficient and sustainable technology to address the problem resulting from increasing impervious surfaces, especially excess urban heat and stormwater runoff.
Compared to other technologies, green roofs do not need extra space at ground level and can also provide additional benefits to cities through provision of multiple ecosystem services.
Green roofs are generally constructed as monocultures to accommodate the extreme conditions and climates on the top of buildings, which mean such ecosystem services are lost.
Zheng looked at designing the green roof system, where components are chosen to mimic the structure and function of natural ecosystems to provide more diverse and higher performing systems. Research questions were:
- Can we use ecosystem mimicry to improve green roof performance in stormwater retention and water quality?
- Can functional diversity improve green roof performance and resilience?
Zhang Z, Szota C, Fletcher TD, Williams NSG, Farrell C (2019) Green roof storage capacity can be more important than evapotranspiration for retention performance. Journal of Environmental Management 232:404-412.