ASLA’s The Dirt recently covered the 2010 Dumbarton Oaks Garden and Landscape Study Symposium. This year’s focus was “Designing Wildlife Habitats,” which looked at ways to preserve biodiversity in rural and urban environments. America’s cities are an appropriate laboratory for such a movement, given that many city-dwellers’ encounters with wildlife are limited to rats, raccoons and pigeons.
The inherent traits of the urban environment: warmer and drier air, poor nutrient cycling and high levels of pollution hinder efforts to attract and sustain wildlife populations. The forest fragmentation that accompanies urban development displaces species which require large swaths of contiguous habitat, including many mammals and forest interior songbirds. Even where large preserves exist, suitable habitats must be connected by park corridors to other wild places to maintain wildlife populations. On the other hand, a park system of smaller, scattered parks close to neighborhoods is more accessible to humans than one of a few, large, concentrated parks. Additionally, many of the features of parks which attract wildlife, like multi-level vegetative canopy and tall, unmowed grass, are incompatible with park amenities like athletic fields, playgrounds, and manicured gardens.
In spite of these challenges, access to wildlife has significant benefits for park users. Spending just a few minutes in a natural setting is correlated with improved cognitive function and emotional outlook. Additional research suggests that bird watching improves mood, promotes social cohesion, and can slow or reverse the onset of Alzheimer’s. Park designers need not pit the needs of ecosystems against the needs of users; ecosystem integrity is an important amenity for many park-goers.
Urban nature preserves, like Jamaica Bay in New York and oil-threatened Bayou Sauvage in New Orleans are wild treasures. But even small designed parks can provide important wildlife habitat while supporting recreational use, through park connectivity like in Boston and Minneapolis, or careful plant selection, like in Chicago’s green roofs or Washington D.C.’s butterfly garden. The connection with our natural heritage is a cherished privilege for city dwellers; one which merits inclusion in our vision for livable cities.