A land purchase meant to thwart Long Island McMansion mania is expected to be approved Monday by the Nassau County Legislature. The measure will preserve 108 nature-packed acres snapped up for $32 million taxpayer dollars.

If approved, the county will take over seven different properties, including three acres of wetlands in Baldwin, two tracts of land in Old Westbury, one in Glen Cove and three in Oyster Bay Cove. Nassau voters are largely behind the county?s efforts. In 2004, they approved a $50 million referendum to create an open space program for Nassau County.

Environmentalists say the only way to save the dwindling number of pristine natural acres is to buy them. Lawmakers say they have to make their purchases slowly and steadily so as not to blow through their approved funding even if it means the loss of some land. Since the list of purchasable properties was drawn up several parcels of land have been lost to developers, including 40 acres in Old Westbury.