Designer ecosystems are considered a key mitigation strategy for the loss of ecosystem services in urban areas. Human-made systems have been successful at restoring or replicating particular ecological services such as stormwater retention, pollutant removal, or air temperature regulation in the developed landscape. One increasingly commonly method for designing ecosystems in urban areas are through vegetated or "green" roofs. Green roofs rely upon plants and growing media installed on a roof membrane to mitigate the impact traditional roofing systems have on the surrounding environment.

Results/Conclusions

Using green roofs as a case study, we investigate why many engineered systems are inherently limited in their ability to restore ecosystem forms and functions. Some of these limitations include: limited time horizons for ecosystem complexity to develop, evolutionary discontinuity, required external material and energy inputs, and socially constructed maintenance and aesthetic demands. Understanding current limitations can help designers and ecologists work towards a new framework for the design and construction of ecosystems that explicitly integrates key ecological principles with engineering technology to maximize sustainable restoration potential in urban areas.