USA data on loss of open spaces...

from the http://www.landtrustalliance.org/

Latest Data on Land Lost to Development The 2007 National Resources Inventory has been released and provides the latest statistical data about land cover and use, soil erosion and prime farmland and wildlife and wetlands. The report is used to support agricultural and environmental policy development and conservation programs.

Where is All the Protected Land in the U.S.? Learn more about federal, state and locally protected areas with the newly updated Protected Areas Database of the United States (PAD-US). The USGS Gap Analysis Program has just published version 1.1 of this national GIS dataset. The national dataset, organized by state, is available for download at the GAP PAD-US website. http://www.protectedlands.net/  http://gapanalysis.nbii.gov/portal/server.pt/community/maps_and_data/1850/