The planned community of Reston is having a hard time deciding what to do with a large tract of open space land that for years has been left undisturbed except for a few trails.

The Reston Home Owners Association held a public hearing last week for residents to discuss possible uses for the 70-acre parcel located in the southern part of Reston. Part of the tract -- 40 acres wedged between Glade Drive and Lawyers Road -- until recently was called the Nature Center.

At issue now is whether to leave the site as is, in a natural state with a partial trail system, or to develop it to encourage more visitors, looking forward to the time when Reston has grown to a projected population of 60,000.

Planning groups of residents and professional naturalists have suggested expanding the existing path system with trail markers and ecological stations and creating managed meadowlands and forests. Probably the most controversial proposal is for a pavilion and a 35-space parking lot.

Most speakers at the hearing urged the association to leave the area unchanged. Some said that development would compromise the ideals of Reston founder Robert E. Simon. Several who protested any changes live in homes backing on the woods of the open space area. Other speakers supported such limited uses of the space as facilities for day campers.

The parcel constitutes 40 acres already owned and managed by the homeowners associaiton and 30 adjacent acres that are expected to be deeded to the association by Reston Land Corp.

No date has been set for the handover, according to Reston Land Corp. president Francis Steinbauer, although it is expected to come as the developer finishes work in the south part of Reston, as the company is now doing, and moves its bulldozers north across Rt. 606.

Responding to residents' criticism over the developer's involvement in the open space issue, Steinbauer said Reston Land Corp. has no ideas on what should go there, but wants to focus residents' attention on it. "We are concerned about the community and we want to make sure that the assets that are given to the community are thought about," he said.

According to Judi Ushio, president of the homeowners association's board of directors, the board will decide how to use the site after surveying residents and holding more committee meetings.