The Habitat Value and Best Practices of Meadow Ecoroofs

Abstract

Designing ecoroofs with the intent of providing habitat is a relatively new field. Contributing to its development, this multi‐phase observational and ecological study spans over 12 years and assesses the habitat value of ecoroofs in the Pacific Northwest region of the United States. Original habitat ecoroofs built on the Gunderson Marine industrial production site from 2011 to 2014 were modeled after native wildflower meadows. Following advisement on habitat design parameters and planting for the meadow ecoroofs, Gunderson Marine commissioned a study to establish and compare habitat values of its four ecoroofs and two control ground sites ranging in size from 530 to 1,015 ft². Was the value of habitat on ecoroofs comparable to that of nearby ground sites? Using a habitat functions matrix approach based on standardized field inventory, the study consistently found ecoroofs designed for habitat can offer a marginally greater value of habitat than comparable ground sites. Over time, the study has also taken a broader view on the habitat of the ecoroofs as the systems evolve ecologically. Comprehensive best practices have been developed through an ecological analysis of the ecoroofs. These include design parameters and an ecologically balanced native plant list, along with establishment and maintenance procedures required to avoid long‐term development issues with ecoroofs and wildflower meadows. Implementation of this knowledge could help to reverse decades of urban habitat degradation, offering efficient, scalable, ecological, and resilient urban design solutions for industrial areas that until now were not considered to be potential urban wildlife habitat.