Anti-development activists in Baltimore County are tapping a comprehensive, once-every-four-years rezoning process to save more than 2,300 acres of threatened land.

The county received about 310 requests for rezoning before last week?s deadline for property owners, county agencies, developers and community groups, said Jeff Mayhew, the county?s community planning chief. Many parcels are already slated for development and requests for rezoning are builders? attempts to maximize space ? and opponents? strategy to stop them.