The implications are that the total assets shown on the balance sheet may not reflect the true situation. The trustees should consider revaluing land values from time to time and seek professional view, if appropriate.
There is no automatic link between the value of a property and its insurance value for rebuilding purposes. Many people seem to think they they should insure a property for its market value; this is nonsense. Rebuilding cost reflects demolition following a buildings total destruction in a fire, say, then reconstruction. In parts of the country where market valuations are high, the rebuilding cost will be far less. The difference is the value of the land, which cannot be destroyed.