The Lowcountry Open Land Trust has raised enough money to purchase 17 acres to expand Angel Oak Park, but an apartment community may be built on an adjacent 17 acres.

If you go

What: Ceremony to celebrate preserving 17 acres adjacent to Angel Oak Park

When: 1 p.m., Thursday

Where: Angel Oak Park, Johns Island.

Charleston Mayor Joe Riley said the land trust hopes also to buy and preserve the second portion of the 34-acre parcel, but the price the Raleigh-based Dominion Realty Partners is asking for it may be too high.

Riley would not say how much the developer wants for the property, "but there's a wide chasm between the Lowcountry Open Land Trust and the developer on cost," he said.

Conservationists have said they want the land around the historic tree on Johns Island protected from intense development to maintain the health of the massive live oak, which is believed to be at least several centuries old.

Elizabeth Hagood, the trust's executive director, has called the property "an ecological preserve." She also said that keeping that land in its natural state is essential to the health of the Angel Oak. The ancient tree needs an expanded forest that's natural, she said.

The Raleigh-based Coastal Federal Credit Union has owned the property since it fell into foreclosure during the economic downturn; Dominion has a contract with the bank to purchase it.

The land was set to be developed with multifamily homes and businesses before it fell into foreclosure.

Now, Dominion plans to build an apartment community on the land, which would include roads and many buildings comprising at least 250 rental units, Riley said. The plan also includes some commercial space on Maybank Highway.

The developer already has technical, engineering and design approvals from the city, Riley said. But Dominion hasn't yet sought building permits. The land, Riley said, is properly zoned for the type of development Dominion has planned.

Andy Andrews, Dominion's president and chief executive officer, did not respond to several voicemail messages for comment.

Riley said representatives from the trust, city and Charleston County currently are discussing the issue with the bank and Dominion. "It would be wonderful to acquire the remaining 17 acres," he said. "It's a work in progress."

Hagood said the trust also would consider preserving just a portion of the second 17 acres, but she hopes to save all of it from development. "We've heard from the community that it's very important to preserve the rest if it's available. Ideally, we would love to see it all protected."

The trust will close on the first 17 acres Thursday, Hagood said. That parcel cost $3.6 million. Charleston County contributed $2.4 million from the rural Greenbelt program, $890,000 came from the state Conservation Bank, and the city contributed $250,000. The rest came from 10,000 private donors who made small contributions.

The trust raised about $4 million for the $3.6 million property, Hagood said. The balance will be used either toward the purchase of the second 17 acres or for education programs related to the Angel Oak. "The money stays with the tree," she said.

Reach Diane Knich at 843-937-5491 or on Twitter at @dianeknich.