Amid the gloom of the real-estate downturn, one group has cause to celebrate: conservationists. Rising housing inventories and slackening demand are causing some developers to sell unused tracts and hold off on purchasing new ones. That has opened the way for local governments and nonprofits like the San Francisco-based Trust for Public Land to snap up property, from Florida to Oregon, that can be set aside for parks and recreation. "In a boom market, it's very difficult for us to compete with developers," says Badge Blackett, TPL's director of projects in New England, where the group closed last June on 360 acres along the Nashua River. "It's in this nub of a downturn that the opportunities really present themselves."

In Florida, a region that has been especially hard hit by the tanking market, cities and counties are clamoring for state grant money to buy up land for public use. In 2007 alone, applications for such funds reached $272 million, which is twice the amount in 2004. And Gov. Charlie Crist has instructed the state Department of Environmental Protection to explore new land-acquisition opportunities. Out West, the city of Phoenix bought a 963-acre parcel of pristine desert for $85 million—without competition—in November. A slice of that property will be set aside for a park, ball fields and a library, but the rest will remain open space. The city is now eyeing the next property on its wish list, which totals as much as 8,000 acres of land. Up in Portland, Ore., TPL will close next month on a 27-acre property purchased from a developer who had planned to build a residential neighborhood on it before the market began to sink.

There's just one potential brake on all this activity: the current economic downturn, which is reducing the tax revenue that cities and counties are using to fund their conservation efforts. That's one reason government officials are rushing to take advantage of market conditions while they still can. "Timing is everything," says David Richert, Phoenix's liaison to the state Land Department. "The pressure is there not to miss the opportunity."