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Are wildlife subdivisions designed for conservation helping?

Large projects built by weathy developers have the best ecosystem impact track records



For millennia, Colorado's Yampa River Valley has followed the rhythms of wildlife mating and migration, the habits of elk and grouse and bear. The arrival of ranching in the 1880s altered the pattern a little, but radical change didn't occur until the last half of the 20th century. That's when the big ranches began to be broken up into small ranchettes and vacation-home lots, the kind of low-density exurban sprawl responsible for habitat fragmentation across the West.

Desperate to preserve Routt County's character, in the mid-1990s its commissioners fought to pass Land Preservation Subdivision ordinances, or LPS. It was an early form of conservation development, an increasingly popular land-planning tool that develops part of a property to fund the preservation of the rest.

Conservation development is usually regulated at the county level. Ordinances encourage developers to cluster houses on a portion of land and leave 40 to 80 per cent of it as open space, and often give a "density bonus" for such clustering, allowing up to 70 per cent more housing units per project.

Such developments typically sell well and command premium prices. They feel in touch with an agricultural past, where people can live within walking distance of hiking trails and fishing ponds. And they've found favour across the West: The passage of such ordinances took off in the 1990s and has more than doubled in the last decade.

They seem to offer a way for mountain communities to have it all. A 2011 study estimated that conservation development has preserved nearly 10 million acres across the U.S. since the 1960s. But questions about its effectiveness remain: Is that open space really helping to maintain biodiversity?

"The key to integrating nature and urban growth is scale," says Armando Carbonell, chair of the Department of Planning and Urban Form at the Lincoln Institute of Land Policy in Cambridge, Mass. Local land planners and developers, he says, need to understand both the ecosystem context and the ecological consequences of their actions.

Sarah Reed, a conservation biologist with Colorado State University and the Wildlife Conservation Society, co-founded the Center for Conservation Development at CSU in fall 2010 to assess county development choices and their ecological consequences.

In 2010, Reed and her coworkers examined land-planning ordinances in all 414 counties of the 11 western states. While over a third of the counties had regulations that promoted some form of conservation development, many did so in ways unlikely to preserve critical wildlife habitat or other natural values. Few promoted land stewardship, or ensured that open space parcels were contiguous within or among developments.

One of the biggest issues, Reed concluded, is the quality and type of data used to create the conservation design. Her preliminary results show that only 13 per cent of the West's conservation development ordinances mandate a study of the property's ecological attributes. "There's no reason to believe that (the land that) got protected is any better than what got developed," Reed says. In contrast, she points to Routt County, which specifically requires developers to identify and avoid "Critical Habitat of Threatened and/or Endangered species, including nesting, roosting, mating, birthing and feeding areas."