Bringing Life to Urban Landscapes

April 10, 2014

triangle land conservancy

All over the world, national government entities and development groups have been investing in ecosystem restoration. While their efforts may be laudable, writes Richard Coniff for Yale Environment 360, the actual results are often not so positive. With multiple studies summarizing the failure of restored ecosystems to “match the performance of natural systems” or even “meet their own minimal performance targets,” scientists are looking towards new methodologies and partnerships to “fix” some of the world’s most ailing ecosystems.

The newest solution is to create “designed experiments,” which Conniff defines as “experiments designed by ecologists and incorporated into development and landscape restoration projects to test which alternative approaches work best.” The beauty of this methodology is it allows progress to be made on the “project at hand,” while simultaneously providing “a scientific basis for making subsequent projects more successful.”

This sounds like a good idea in theory, but what does it mean in practice? Take what seems like a simple project – tree planting in New York City. The goal is to plant trees covering nearly 2,000 city acres; however, the trees have to survive, and doing so in a city setting is not as simple as it may sound. Which species are most suited for city life? For crowding? For parks or street corners? With or without compost?

To answer these questions, Alexander Felson, a Yale urban ecologist and landscape architect, devised different study plots in the initial phases of the project to provide an ongoing source of data as New York trees are continually planted. As he publishes his findings, cities that would like to replicate the tree planting initiative will have a better understanding of what works and what doesn’t.  Though the project is only a few years old, they have already discovered some useful results: “competition from shrubs will actually make [trees] grow faster, not slower. Some trees, like basswood, do better in more diverse plantings; others, like oaks, prefer less diversity. Compost doesn’t seem to make a difference for the first two years but kicks in during year three.” All these findings will be helpful as the city continues to invest in trees as green infrastructure.

Designed experiments are not merely an American venture. In China, Kongjian Yu tests pond depth and size in Qiaoyuan Wetland Park, “a naturalized landscape of ponds, grasses, and reeds” which restored “a 54-acre forming shooting range that had become an illegal dumping ground.” As he uncovers data on which pond design is best for improving water quality, he can incorporate this information into changes in the Qiaoyuan Wetland Park as well as future wetland park restoration projects.

As we move forward, restoration will become even more critical to local ecosystem health as well as mitigating global climate change. If each project incorporates some element of a designed experiment, our knowledge base could rapidly expand, and thus each restoration project could improve upon itself in addition to being more successful than the iterations that came before it.

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