In cities, even Burlington, there is a lack of nature, soils, biodiversity, and ‘green’. Impermeable surfaces channel stormwater runoff down the hill directly into Lake Champlain. A proportional lack of trees elevates temperatures and causes heat island effect. To fix the problem our first reaction is to try to put back the nature that we’ve removed, to put a few artificial organs into an otherwise still functioning body – and in rural areas where fragments of functioning ecosystems remain that we can splice into, restoration efforts are successful. But what happens when the whole ecosystem in an urban context has been destroyed? Where there are no native soils left, no open land large enough to accommodate the vegetation that once lived there, no corridors extensive or wide enough for migrating terrestrial animals – in essence no hope of ever replacing the complexity and diversity of the original system? That’s when you start hearing terms like Urban Greenspace, Novel Ecosystems, and Future Nature.
Nigel Dunnett meadow
I heard a presentation on Novel Ecosystems last winter by Nigel Dunnett, a Professor of Planting Design at the University of Sheffield, UK. He and James Hitchmough of the Department of Landscape along with Sarah Price designed the meadows at the London Olympic Park. (Thomas Rainer has a great blog post about Dunnett’s meadows here.) They went to great lengths to create sterile planting environments, with carefully designed soil mixes, weed-free seeds of annual and perennial species choreographed to bloom in a dramatic sequence, planted in exact weights and proportions, and then groomed to create incredibly colorful “pictorial meadows” for the Games. This approach has come to be known as ‘The Sheffield School’ of planting design.
Dunnett and Hitchmough wrote a book called The Dynamic Landscape, Design, Ecology and the Management of Urban Planting in 2004. Dunnett also co-authored a book on Rain Garden Design (the first one I ever read) in 2007. In both instances his expertise lays firmly in the built environment and in finding ways to marry aesthetics with functional solutions. He proposes that we need to reconsider our definition of ‘ecological’ in the urban context, and specifically that native plant communities may not be the best adapted plants for highly modified and disturbed urban sites. Instead a Novel Ecosystem approach could be used that is based on:
- choosing species from different places to maximize aesthetic and ecological functions
- choosing species that are adapted to the urban environment
- developing systems that deliver ecosystem services (slowing stormwater, providing nectar and pollen, nesting sites etc.) with minimal inputs (fertilizer, water, weeding).
Highline in August
I agree with him that in many cases it would be impossible to try to recreate a natural system where none exists. The High Line is often given as an example of re-introducing a wild aesthetic using plants (many of them native) that are adapted to an urban environment. I hope we continue to see more examples of a wild aesthetic in urban areas mostly because they generally contain a larger diversity of species. In comparison to NYC, Burlington is more of an urban island floating in a sea of functioning ecosystems, and it’s still possible to splice into those systems. Where we can, I think it’s still a good idea to select native plants from our knowledge of the plant communities that existed here before. There are lots of exceptions of course – you can’t put Clayplain Forest species on an extensive green roof and have any of them survive. So yes, it’s a balance of native and non-native, ecological and aesthetic.
Here’s an example of an urban backyard we designed for the VT Flower Show in 2011 that demonstrates how this Novel Ecosystem concept could be applied here – we mimic the style of woodland and meadow plant communities, as well as urban agriculture (greenhouse, spindle fruit trees, compost and chicken run) and green infrastructure components (Permeable paving, RainXchange system, green wall, green roof). The scale is micro rather than macro, as are most urban backyards – yet if we can cobble together many examples of this type of landscape we might supply some of those ecosystem services that are lost in an urban setting.
2011 VT Flower Show Plan
Linden L.A.N.D. Display 2011 Flower Show