
Qiaoyuan Wetland Park in Tianjin, China, has terraced ponds that incorporate designed experiments to monitor benefits.
My latest for Yale Environment 360:
Restoring degraded ecosystems — or creating new ones — has become a huge global business. China, for instance, is planting 90 million acres of forest in a swath across its northern provinces. And in North America, just in the past two decades, restoration projects costing $70 billion have attempted to restore or re-create 7.4 million acres of marsh, peatland, floodplain, mangrove, and other wetlands.
This patchwork movement to rebuild the natural world ought to be good news. Such projects are, moreover, likely to become far more common as the world rapidly urbanizes and as cities, new and old, turn to green infrastructure to address problems like climate change, flood control, and pollution of nearby waterways. But hardly anyone does a proper job of measuring the results, and when they do, it generally turns out that ecological restorations seldom function as intended.
A 2012 study in PLOS Biology, for instance, looked at 621 wetland projects and found most had failed to deliver promised results, or match the performance of natural systems, even decades after completion. Likewise, an upcoming study by Margaret A. Palmer at the University of Maryland reports that more than 75 percent of river and stream restorations failed to meet their own minimal performance targets. “They may be pretty projects,” says Palmer, “but they don’t provide ecological benefits.”
Hence the increasing interest in what Alexander Felson, an urban ecologist and landscape architect at the Yale School of Forestry and Environmental Studies, calls “designed experiments” — that is, experiments designed by ecologists and incorporated into development and landscape restoration projects to test which alternative approaches Read the rest of this entry »