In 1998 Leslie Sauer Jones wrote The Once and Future Forest: A Guide to Forest Restoration Strategies. Embedded within the book’s forward, landscape architect Ian McHarg implored: “We must participate, with action and all the experience we can bring” in order to attempt to reverse environmental degradation and we can no longer expect our actions to be reversed with inaction. He further suggested that we embrace, “important havens, such as the interstices of cities” as critical canvasses for habitat enhancement and expansion for our native plants and animals.
Within our cities, large, contiguous tracts of vegetation, such as urban forests and riverfront corridors, offer critical ecological value potential. However, in more densely developed fragments of the city, where landscape design increasingly occurs, researchers are discovering that purposely selected woody plants can similarly provide animal species with viable urban habitat. Conceptualizing the ecological value of these urban interstices may be a function of perspective, or scale.
When high-intensity rainfall events roll through cities, particularly those with combined sewer systems, peak flows increasingly overwhelm grey infrastructure, compromise water quality, and induce sedimentation and erosion. New research suggests that engineered soil and purposely selected plants within green infrastructure may help offset these flows by offering more benefit than most stormwater engineering models and municipalities acknowledge.
A handful of progressive entities – like the Chesapeake Stormwater Network and the Commonwealth of Virginia – now award extra stormwater credit for management approaches that deploy high-performance engineered soils, dense and varied planting palettes, or an inter-connected series of green infrastructure elements. More research is needed, however, to mobilize engineers, designers, and policy makers to rely more heavily on the “green” in green infrastructure.