Valuable properties and heritage items are not being offered to the Irish people because this State has no proper legislation to hold them in trust, according to An Taisce.
Mr John Ducie, vice-chairman of An Taisce, the National Trust for Ireland, said he had personal experience of would-be donors who had not handed over properties simply because there were insufficient safeguards.
"An Taisce holds properties in trust for the people of Ireland. In reality, a county manager can come along and place a CPO (compulsory purchase order) on it for a road," Mr Ducie said.
The State "cannot do it all", he said. There needed to be a third partner in overseeing heritage. In particular, there needed to be a contract between the non-governmental organisation and the State to put in place the necessary safeguards so that the property held in trust could not be interfered with or transferred from the people.
Ireland had fallen well behind most other European states - including states of the former communist bloc - in terms of heritage protection, he said.
Mr Ducie also called for tax credits for donors who gave properties and paintings, particularly with regard to death duties.
Having a properly constituted national trust was particularly important for tourism, he said. The Kerry coast, for example, compared poorly with the Antrim coast: "You can't walk along the Kerry coast; you can walk along the Antrim coast." This was because the Neptune fund, run by the North of Ireland heritage trust, had managed to buy strips of the coast, in many cases just enough to allow walkers room to pass.
All trust organisations had turned to sustainable tourism developments as a key to keeping rural life alive, he said.
"This does not mean building massive interpretative centres on the Cliffs of Moher, for instance."
Sustainable tourism meant enhancing the intrinsic value of heritage, he said. Much of tourism in Ireland was currently unsustainable. The profits made by hotels such as those in Killarney, for example, were being moved out of the area, and not invested back into environment and heritage, which were what attracted tourists in the first place.
During the last government, An Taisce presented the draft heads of a Heritage Trust Act to the Oireachtas committee on heritage, where it received cross-party backing. The full heads would now be brought back to the appropriate committee, probably before Christmas.